text:
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System.Threading.Tasks;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.RemoveUnnecessaryCast;
using Microsoft.CodeAnalysis.Editor.UnitTests.CodeActions;
using Microsoft.CodeAnalysis.Test.Utilities;
using Microsoft.CodeAnalysis.Testing;
using Roslyn.Test.Utilities;
using Xunit;

namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.RemoveUnnecessaryCast
{
    using VerifyCS = CSharpCodeFixVerifier<
        CSharpRemoveUnnecessaryCastDiagnosticAnalyzer,
        CSharpRemoveUnnecessaryCastCodeFixProvider>;

    public class RemoveUnnecessaryCastTests
    {
        [Theory, CombinatorialData, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public void TestStandardProperty(AnalyzerProperty property)
            => VerifyCS.VerifyStandardProperty(property);

        [WorkItem(545979, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545979")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToErrorType()
        {
            var source =
@"class Program
{
    static void Main()
    {
        object s = "";
        foreach (object x in ({|CS0246:ErrorType|})s)
        {
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                new[]
                {
                    // /0/Test0.cs(5,20): error CS1010: Newline in constant
                    DiagnosticResult.CompilerError("CS1010").WithSpan(5, 20, 5, 20),
                    // /0/Test0.cs(5,22): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(5, 22, 5, 22),
                },
                source);
        }

        [WorkItem(545137, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545137"), WorkItem(870550, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/870550")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task ParenthesizeToKeepParseTheSame1()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class Program
{
    static void Main()
    {
        int x = 2;
        int i = 1;
        Goo(x < [|(int)|]i, x > (2 + 3));
    }

    static void Goo(bool a, bool b) { }
}",

            @"
class Program
{
    static void Main()
    {
        int x = 2;
        int i = 1;
        Goo(x < (i), x > (2 + 3));
    }

    static void Goo(bool a, bool b) { }
}");
        }

        [WorkItem(545146, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545146")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task ParenthesizeToKeepParseTheSame2()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;

class C
{
    static void Main()
    {
        Action a = Console.WriteLine;
        ([|(Action)|]a)();
    }
}",

            @"
using System;

class C
{
    static void Main()
    {
        Action a = Console.WriteLine;
        a();
    }
}");
        }

        [WorkItem(545160, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545160")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task ParenthesizeToKeepParseTheSame3()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;

class Program
{
    static void Main()
    {
        var x = (Decimal)[|(int)|]-1;
    }
}",

            @"
using System;

class Program
{
    static void Main()
    {
        var x = (Decimal)(-1);
    }
}");
        }

        [WorkItem(545138, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545138")]
        [WorkItem(44422, "https://github.com/dotnet/roslyn/issues/44422")]
        [Fact(Skip = "https://github.com/dotnet/roslyn/issues/44422"), Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveTypeParameterCastToObject()
        {
            var source =
@"class С
{
    void Goo<T>(T obj)
{
    int x = (int)(object)obj;
}
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                new[]
                {
                    // /0/Test0.cs(1,8): error CS1056: Unexpected character '¡'
                    DiagnosticResult.CompilerError("CS1056").WithSpan(1, 8, 1, 8).WithArguments("¡"),
                    // /0/Test0.cs(1,8): error CS1513: } expected
                    DiagnosticResult.CompilerError("CS1513").WithSpan(1, 8, 1, 9),
                    // /0/Test0.cs(1,8): error CS1514: { expected
                    DiagnosticResult.CompilerError("CS1514").WithSpan(1, 8, 1, 9),
                    // /0/Test0.cs(2,1): error CS1022: Type or namespace definition, or end-of-file expected
                    DiagnosticResult.CompilerError("CS1022").WithSpan(2, 1, 2, 2),
                    // /0/Test0.cs(7,1): error CS1022: Type or namespace definition, or end-of-file expected
                    DiagnosticResult.CompilerError("CS1022").WithSpan(7, 1, 7, 2),
                },
                source);
        }

        [WorkItem(545139, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545139")]
        [WorkItem(44422, "https://github.com/dotnet/roslyn/issues/44422")]
        [Fact(Skip = "https://github.com/dotnet/roslyn/issues/44422"), Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastInIsTest()
        {
            var source =
@"using System;

class С
{
    static void Main()
{
    DayOfWeek[] a = {
    };
    Console.WriteLine((object)a is int[]);
}
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                new[]
                {
                    // /0/Test0.cs(3,8): error CS1056: Unexpected character '¡'
                    DiagnosticResult.CompilerError("CS1056").WithSpan(3, 8, 3, 8).WithArguments("¡"),
                    // /0/Test0.cs(3,8): error CS1513: } expected
                    DiagnosticResult.CompilerError("CS1513").WithSpan(3, 8, 3, 9),
                    // /0/Test0.cs(3,8): error CS1514: { expected
                    DiagnosticResult.CompilerError("CS1514").WithSpan(3, 8, 3, 9),
                    // /0/Test0.cs(4,1): error CS1022: Type or namespace definition, or end-of-file expected
                    DiagnosticResult.CompilerError("CS1022").WithSpan(4, 1, 4, 2),
                    // /0/Test0.cs(11,1): error CS1022: Type or namespace definition, or end-of-file expected
                    DiagnosticResult.CompilerError("CS1022").WithSpan(11, 1, 11, 2),
                },
                source);
        }

        [WorkItem(545142, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545142")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastNeedForUserDefinedOperator()
        {
            var source =
@"class A
{
    public static implicit operator A(string x)
    {
        return new A();
    }
}

class Program
{
    static void Main()
    {
        A x = (string)null;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545143, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545143")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemovePointerCast1()
        {
            var source =
@"unsafe class C
{
    static unsafe void Main()
    {
        var x = (int)(int*)null;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545144, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545144")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToObjectFromDelegateComparison()
        {
            // The cast below can't be removed because it would result in the Delegate
            // op_Equality operator overload being used over reference equality.

            var source =
@"using System;

class Program
{
    static void Main()
    {
        Action a = Console.WriteLine;
        Action b = Console.WriteLine;
        Console.WriteLine(a == (object)b);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545145, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545145")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToAnonymousMethodWhenOnLeftOfAsCast()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"using System;

class C
{
    static void Main()
    {
        var x = (Action)delegate {
        }

        [|as Action|];
    }
}",
@"using System;

class C
{
    static void Main()
    {
        var x = (Action)delegate {
        };
    }
}");
        }

        [WorkItem(545147, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545147")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastInFloatingPointOperation()
        {
            var source =
@"class C
{
    static void Main()
    {
        int x = 1;
        double y = (double)x / 2;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545157, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545157")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveIdentityCastWhichAffectsOverloadResolution1()
        {
            var source =
@"using System;

class Program
{
    static void Main()
    {
        Goo(x => (int)x);
    }

    static void Goo(Func<int, object> x)
    {
    }

    static void Goo(Func<string, object> x)
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545158, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545158")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveIdentityCastWhichAffectsOverloadResolution2()
        {
            var source =
@"using System;

class Program
{
    static void Main()
    {
        var x = (IComparable<int>)1;
        Goo(x);
    }

    static void Goo(IComparable<int> x)
    {
    }

    static void Goo(int x)
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545158, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545158")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveIdentityCastWhichAffectsOverloadResolution3()
        {
            var source =
@"using System;

class Program
{
    static void Main()
    {
        var x = (IComparable<int>)1;
        var y = x;
        Goo(y);
    }

    static void Goo(IComparable<int> x)
    {
    }

    static void Goo(int x)
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545747, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545747")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastWhichChangesTypeOfInferredLocal()
        {
            var source =
@"class C
{
    static void Main()
    {
        var x = (long)1;
        x = long.MaxValue;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545159, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545159")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNeededCastToIListOfObject()
        {
            var source =
@"using System;
using System.Collections.Generic;

class C
{
    static void Main()
    {
        Action<object>[] x = {
        };
        Goo(x);
    }

    static void Goo<T>(Action<T>[] x)
    {
        var y = (IList<Action<object>>)(IList<object>)x;
        Console.WriteLine(y.Count);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545287, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545287"), WorkItem(880752, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/880752")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInParameterDefaultValue()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class Program
{
    static void M1(int? i1 = [|(int?)|]null)
    {
    }
}",

@"
class Program
{
    static void M1(int? i1 = null)
    {
    }
}");
        }

        [WorkItem(545289, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545289")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInReturnStatement()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class Program
{
    static long M2()
    {
        return [|(long)|]5;
    }
}",

@"
class Program
{
    static long M2()
    {
        return 5;
    }
}");
        }

        [WorkItem(545288, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545288")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInLambda1()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;
class Program
{
    static void M1()
    {
        Func<long> f1 = () => [|(long)|]5;
    }
}",

@"
using System;
class Program
{
    static void M1()
    {
        Func<long> f1 = () => 5;
    }
}");
        }

        [WorkItem(545288, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545288")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInLambda2()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;
class Program
{
    static void M1()
    {
        Func<long> f1 = () => { return [|(long)|]5; };
    }
}",

@"
using System;
class Program
{
    static void M1()
    {
        Func<long> f1 = () => { return 5; };
    }
}");
        }

        [WorkItem(545288, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545288")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInLambda3()
        {
            var source =
            @"
using System;
class Program
{
    static void M1()
    {
        Func<long> f1 = _ => { return [|(long)|]5; };
    }
}";
            var fixedSource =
@"
using System;
class Program
{
    static void M1()
    {
        Func<long> f1 = _ => { return 5; };
    }
}";

            await new VerifyCS.Test
            {
                TestState =
                {
                    Sources = { source },
                    ExpectedDiagnostics =
                    {
                        // /0/Test0.cs(7,25): error CS1593: Delegate 'Func<long>' does not take 1 arguments
                        DiagnosticResult.CompilerError("CS1593").WithSpan(7, 25, 7, 49).WithArguments("System.Func<long>", "1"),
                    },
                },
                FixedState =
                {
                    Sources = { fixedSource },
                    ExpectedDiagnostics =
                    {
                        // /0/Test0.cs(7,25): error CS1593: Delegate 'Func<long>' does not take 1 arguments
                        DiagnosticResult.CompilerError("CS1593").WithSpan(7, 25, 7, 43).WithArguments("System.Func<long>", "1"),
                    },
                },
            }.RunAsync();
        }

        [WorkItem(545288, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545288")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInLambda4()
        {
            var source =
            @"
using System;
class Program
{
    static void M1()
    {
        Func<long> f1 = _ => [|(long)|]5;
    }
}";
            var fixedSource =
@"
using System;
class Program
{
    static void M1()
    {
        Func<long> f1 = _ => 5;
    }
}";

            await new VerifyCS.Test
            {
                TestState =
                {
                    Sources = { source },
                    ExpectedDiagnostics =
                    {
                        // /0/Test0.cs(7,25): error CS1593: Delegate 'Func<long>' does not take 1 arguments
                        DiagnosticResult.CompilerError("CS1593").WithSpan(7, 25, 7, 37).WithArguments("System.Func<long>", "1"),
                    },
                },
                FixedState =
                {
                    Sources = { fixedSource },
                    ExpectedDiagnostics =
                    {
                        // /0/Test0.cs(7,25): error CS1593: Delegate 'Func<long>' does not take 1 arguments
                        DiagnosticResult.CompilerError("CS1593").WithSpan(7, 25, 7, 31).WithArguments("System.Func<long>", "1"),
                    },
                },
            }.RunAsync();
        }

        [WorkItem(545291, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545291")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInConditionalExpression1()
        {
            var source =
            @"
class Test
{
    public static void Main()
    {
        int b = 5;

        long f1 = (b == 5) ? [|(long)|]4 : [|(long)|]5;
    }
}";
            var fixedSource =
@"
class Test
{
    public static void Main()
    {
        int b = 5;

        long f1 = (b == 5) ? 4 : [|(long)|]5;
    }
}";
            var batchFixedSource =
@"
class Test
{
    public static void Main()
    {
        int b = 5;

        long f1 = (b == 5) ? 4 : 5;
    }
}";

            await new VerifyCS.Test
            {
                TestState =
                {
                    Sources = { source },
                },
                FixedState =
                {
                    Sources = { fixedSource },
                    MarkupHandling = MarkupMode.Allow,
                },
                BatchFixedState =
                {
                    Sources = { batchFixedSource },
                },
                CodeFixTestBehaviors = CodeFixTestBehaviors.FixOne,
            }.RunAsync();
        }

        [WorkItem(545291, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545291")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInConditionalExpression2()
        {
            var source =
            @"
class Test
{
    public static void Main()
    {
        int b = 5;

        long f1 = (b == 5) ? [|(long)|]4 : [|(long)|]5;
    }
}";
            var fixedSource =
@"
class Test
{
    public static void Main()
    {
        int b = 5;

        long f1 = (b == 5) ? [|(long)|]4 : 5;
    }
}";
            var batchFixedSource =
@"
class Test
{
    public static void Main()
    {
        int b = 5;

        long f1 = (b == 5) ? 4 : 5;
    }
}";

            await new VerifyCS.Test
            {
                TestState =
                {
                    Sources = { source },
                },
                FixedState =
                {
                    Sources = { fixedSource },
                    MarkupHandling = MarkupMode.Allow,
                },
                BatchFixedState =
                {
                    Sources = { batchFixedSource },
                },
                CodeFixTestBehaviors = CodeFixTestBehaviors.FixOne,
                DiagnosticSelector = diagnostics => diagnostics[1],
            }.RunAsync();
        }

        [WorkItem(545291, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545291")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInConditionalExpression3()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class Test
{
    public static void Main()
    {
        int b = 5;

        long f1 = (b == 5) ? 4 : [|(long)|]5;
    }
}",

@"
class Test
{
    public static void Main()
    {
        int b = 5;

        long f1 = (b == 5) ? 4 : 5;
    }
}");
        }

        [WorkItem(545291, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545291")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNeededCastInConditionalExpression()
        {
            var source =
@"class Test
{
    public static void Main()
    {
        int b = 5;
        var f1 = (b == 5) ? 4 : (long)5;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545291, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545291")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInConditionalExpression4()
        {
            var source =
            @"
class Test
{
    public static void Main()
    {
        int b = 5;

        var f1 = (b == 5) ? [|(long)|]4 : [|(long)|]5;
    }
}";
            var fixedSource =
@"
class Test
{
    public static void Main()
    {
        int b = 5;

        var f1 = (b == 5) ? (long)4 : 5;
    }
}";
            var batchFixedSource =
@"
class Test
{
    public static void Main()
    {
        int b = 5;

        var f1 = (b == 5) ? 4 : (long)5;
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = fixedSource,
                BatchFixedCode = batchFixedSource,
                CodeFixTestBehaviors = CodeFixTestBehaviors.FixOne,
                DiagnosticSelector = diagnostics => diagnostics[1],
            }.RunAsync();
        }

        [WorkItem(545459, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545459")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInsideADelegateConstructor()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;
class Test
{
    delegate void D(int x);

    static void Main(string[] args)
    {
        var cd1 = new D([|(Action<int>)|]M1);
    }

    public static void M1(int i) { }
}",

@"
using System;
class Test
{
    delegate void D(int x);

    static void Main(string[] args)
    {
        var cd1 = new D(M1);
    }

    public static void M1(int i) { }
}");
        }

        [WorkItem(545419, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545419")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveTriviaWhenRemovingCast()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;
class Test
{
    public static void Main()
    {
        Func<Func<int>> f2 = () =>
        {
            return [|(Func<int>)|](/*Lambda returning int const*/() => 5 /*Const returned is 5*/);
        };
    }
}",

@"
using System;
class Test
{
    public static void Main()
    {
        Func<Func<int>> f2 = () =>
        {
            return /*Lambda returning int const*/() => 5 /*Const returned is 5*/;
        };
    }
}");
        }

        [WorkItem(545422, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545422")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInsideCaseLabel()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class Test
{
    static void Main()
    {
        switch (5L)
        {
            case [|(long)|]5:
                break;
        }
    }
}",

@"
class Test
{
    static void Main()
    {
        switch (5L)
        {
            case 5:
                break;
        }
    }
}");
        }

        [WorkItem(545578, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545578")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInsideGotoCaseStatement()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class Test
{
    static void Main()
    {
        switch (5L)
        {
            case 5:
                goto case [|(long)|]5;
                break;
        }
    }
}",

@"
class Test
{
    static void Main()
    {
        switch (5L)
        {
            case 5:
                goto case 5;
                break;
        }
    }
}");
        }

        [WorkItem(545595, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545595")]
        [WpfFact(Skip = "529787"), Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInCollectionInitializer()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        var z = new List<long> { [|(long)0|] };
    }
}",

@"
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        var z = new List<long> { 0 };
    }
}");
        }

        [WorkItem(529787, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529787")]
        [WpfFact(Skip = "529787"), Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastWhichInCollectionInitializer1()
        {
            var source =
@"using System;
using System.Collections.Generic;

class X : List<int>
{
    void Add(object x)
    {
        Console.WriteLine(1);
    }

    void Add(string x)
    {
        Console.WriteLine(2);
    }

    static void Main()
    {
        var z = new X { [|(object)""""|] };
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(529787, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529787")]
        [WpfFact(Skip = "529787"), Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastWhichInCollectionInitializer2()
        {
            var source =
@"using System;
using System.Collections.Generic;

class X : List<int>
{
    void Add(object x)
    {
        Console.WriteLine(1);
    }

    void Add(string x)
    {
        Console.WriteLine(2);
    }

    static void Main()
    {
        X z = new X { [|(object)""""|] };
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545607, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545607")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastInArrayInitializer()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class X
{
    static void Goo()
    {
        string x = "";
        var s = new object[] { [|(object)|]x };
    }
}",
                new[]
                {
                    // /0/Test0.cs(6,20): error CS1010: Newline in constant
                    DiagnosticResult.CompilerError("CS1010").WithSpan(6, 20, 6, 20),
                    // /0/Test0.cs(6,22): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(6, 22, 6, 22),
                },
@"
class X
{
    static void Goo()
    {
        string x = "";
        var s = new object[] { x };
    }
}");
        }

        [WorkItem(545616, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545616")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnneededCastWithOverloadedBinaryOperator()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;
class MyAction
{
    static void Goo()
    {
        MyAction x = null;
        var y = x + [|(Action)|]delegate { };
    }

    public static MyAction operator +(MyAction x, Action y)
    {
        throw new NotImplementedException();
    }
}",

@"
using System;
class MyAction
{
    static void Goo()
    {
        MyAction x = null;
        var y = x + delegate { };
    }

    public static MyAction operator +(MyAction x, Action y)
    {
        throw new NotImplementedException();
    }
}");
        }

        [WorkItem(545822, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545822")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnnecessaryCastShouldInsertWhitespaceWhereNeededToKeepCorrectParsing()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;

class Program
{
    static void Goo<T>()
    {
        Action a = null;
        var x = [|(Action)|](Goo<Guid>)==a;
    }
}",

@"
using System;

class Program
{
    static void Goo<T>()
    {
        Action a = null;
        var x = (Goo<Guid>) == a;
    }
}");
        }

        [WorkItem(545560, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545560")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastWithExplicitUserDefinedConversion()
        {
            var source =
@"using System;

class A
{
    public static explicit operator long(A x)
    {
        return 1;
    }

    public static implicit operator int(A x)
    {
        return 2;
    }

    static void Main()
    {
        var a = new A();
        long x = (long)a;
        long y = a;
        Console.WriteLine(x); // 1
        Console.WriteLine(y); // 2
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545608, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545608")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastWithImplicitUserDefinedConversion()
        {
            var source =
@"class X
{
    static void Goo()
    {
        X x = null;
        object y = (string)x;
    }

    public static implicit operator string(X x)
    {
        return "";
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                new[]
                {
                    // /0/Test0.cs(11,16): error CS1010: Newline in constant
                    DiagnosticResult.CompilerError("CS1010").WithSpan(11, 16, 11, 16),
                    // /0/Test0.cs(11,18): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(11, 18, 11, 18),
                },
                source);
        }

        [WorkItem(545941, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545941")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastWithImplicitConversionInThrow()
        {
            // The cast below can't be removed because the throw statement expects
            // an expression of type Exception -- not an expression convertible to
            // Exception.

            var source =
@"using System;

class E
{
    public static implicit operator Exception(E e)
    {
        return new Exception();
    }

    static void Main()
    {
        throw (Exception)new E();
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545981, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545981")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInThrow()
        {
            // The cast below can't be removed because the throw statement expects
            // an expression of type Exception -- not an expression convertible to
            // Exception.

            var source =
@"using System;

class C
{
    static void Main()
    {
        object ex = new Exception();
        throw (Exception)ex;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545941, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545941")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnnecessaryCastInThrow()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;

class E
{
    static void Main()
    {
        throw [|(Exception)|]new Exception();
    }
}
",

@"
using System;

class E
{
    static void Main()
    {
        throw new Exception();
    }
}
");
        }

        [WorkItem(545945, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545945")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryDowncast()
        {
            var source =
@"class C
{
    void Goo(object y)
    {
        int x = (int)y;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545591, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545591")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastWithinLambda()
        {
            var source =
@"using System;

class Program
{
    static void Main()
    {
        Boo(x => Goo(x, y => (int)x), null);
    }

    static void Boo(Action<int> x, object y)
    {
        Console.WriteLine(1);
    }

    static void Boo(Action<string> x, string y)
    {
        Console.WriteLine(2);
    }

    static void Goo(int x, Func<int, int> y)
    {
    }

    static void Goo(string x, Func<string, string> y)
    {
    }

    static void Goo(string x, Func<int, int> y)
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545606, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545606")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastFromNullToTypeParameter()
        {
            var source =
@"class X
{
    static void Goo<T, S>() where T : class, S
    {
        S y = (T)null;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545744, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545744")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInImplicitlyTypedArray()
        {
            var source =
@"class X
{
    static void Goo()
    {
        string x = "";
        var s = new[] { (object)x };
        s[0] = 1;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                new[]
                {
                    // /0/Test0.cs(5,20): error CS1010: Newline in constant
                    DiagnosticResult.CompilerError("CS1010").WithSpan(5, 20, 5, 20),
                    // /0/Test0.cs(5,22): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(5, 22, 5, 22),
                },
                source);
        }

        [WorkItem(545750, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545750")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnnecessaryCastToBaseType()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class X
{
    static void Main()
    {
        var s = ([|(object)|]new X()).ToString();
    }

    public override string ToString()
    {
        return "";
    }
}",
                new[]
                {
                    // /0/Test0.cs(11,16): error CS1010: Newline in constant
                    DiagnosticResult.CompilerError("CS1010").WithSpan(11, 16, 11, 16),
                    // /0/Test0.cs(11,18): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(11, 18, 11, 18),
                },
@"
class X
{
    static void Main()
    {
        var s = new X().ToString();
    }

    public override string ToString()
    {
        return "";
    }
}");
        }

        [WorkItem(545855, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545855")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnnecessaryLambdaToDelegateCast()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;
using System.Collections.Generic;
using System.Reflection;

static class Program
{
    static void Main()
    {
        FieldInfo[] fields = typeof(Exception).GetFields();
        Console.WriteLine(fields.Any([|(Func<FieldInfo, bool>)|](field => field.IsStatic)));
    }

    static bool Any<T>(this IEnumerable<T> s, Func<T, bool> predicate)
    {
        return false;
    }

    static bool Any<T>(this ICollection<T> s, Func<T, bool> predicate)
    {
        return true;
    }
}
",

@"
using System;
using System.Collections.Generic;
using System.Reflection;

static class Program
{
    static void Main()
    {
        FieldInfo[] fields = typeof(Exception).GetFields();
        Console.WriteLine(fields.Any(field => field.IsStatic));
    }

    static bool Any<T>(this IEnumerable<T> s, Func<T, bool> predicate)
    {
        return false;
    }

    static bool Any<T>(this ICollection<T> s, Func<T, bool> predicate)
    {
        return true;
    }
}
");
        }

        [WorkItem(529816, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529816")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnnecessaryCastInQueryExpression()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;

class A
{
    int Select(Func<int, long> x) { return 1; }

    static void Main()
    {
        Console.WriteLine(from y in new A() select [|(long)|]0);
    }
}",

@"
using System;

class A
{
    int Select(Func<int, long> x) { return 1; }

    static void Main()
    {
        Console.WriteLine(from y in new A() select 0);
    }
}");
        }

        [WorkItem(529816, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529816")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInQueryExpression()
        {
            var source =
@"using System;

class A
{
    int Select(Func<int, long> x)
    {
        return 1;
    }

    int Select(Func<int, int> x)
    {
        return 2;
    }

    static void Main()
    {
        Console.WriteLine(from y in new A()
                          select (long)0);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545848, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545848")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConstructorInitializer()
        {
            var source =
@"using System;

class C
{
    static void Goo(int x, Func<int, int> y)
    {
    }

    static void Goo(string x, Func<string, string> y)
    {
    }

    C(Action<int> x, object y)
    {
        Console.WriteLine(1);
    }

    C(Action<string> x, string y)
    {
        Console.WriteLine(2);
    }

    C() : this(x => Goo(x, y => (int)x), null)
    {
    }

    static void Main()
    {
        new C();
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(529831, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529831")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastFromTypeParameterToInterface()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"using System;

interface IIncrementable
{
    int Value { get; }

    void Increment();
}

struct S : IIncrementable
{
    public int Value { get; private set; }

    public void Increment()
    {
        Value++;
    }
}

class C : IIncrementable
{
    public int Value { get; private set; }

    public void Increment()
    {
        Value++;
    }
}

static class Program
{
    static void Main()
    {
        Goo(new S(), new C());
    }

    static void Goo<TAny, TClass>(TAny x, TClass y)
        where TAny : IIncrementable
        where TClass : class, IIncrementable
    {
        ((IIncrementable)x).Increment(); // False Unnecessary Cast
        ([|(IIncrementable)|]y).Increment(); // Unnecessary Cast - OK

        Console.WriteLine(x.Value);
        Console.WriteLine(y.Value);
    }
}",
@"using System;

interface IIncrementable
{
    int Value { get; }

    void Increment();
}

struct S : IIncrementable
{
    public int Value { get; private set; }

    public void Increment()
    {
        Value++;
    }
}

class C : IIncrementable
{
    public int Value { get; private set; }

    public void Increment()
    {
        Value++;
    }
}

static class Program
{
    static void Main()
    {
        Goo(new S(), new C());
    }

    static void Goo<TAny, TClass>(TAny x, TClass y)
        where TAny : IIncrementable
        where TClass : class, IIncrementable
    {
        ((IIncrementable)x).Increment(); // False Unnecessary Cast
        y.Increment(); // Unnecessary Cast - OK

        Console.WriteLine(x.Value);
        Console.WriteLine(y.Value);
    }
}");
        }

        [WorkItem(529831, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529831")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnnecessaryCastFromTypeParameterToInterface()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;

interface IIncrementable
{
    int Value { get; }
    void Increment();
}

struct S : IIncrementable
{
    public int Value { get; private set; }
    public void Increment() { Value++; }
}

class C: IIncrementable
{
    public int Value { get; private set; }
    public void Increment() { Value++; }
}

static class Program
{
    static void Main()
    {
        Goo(new S(), new C());
    }

    static void Goo<TAny, TClass>(TAny x, TClass y)
        where TAny : IIncrementable
        where TClass : class, IIncrementable
    {
        ((IIncrementable)x).Increment(); // False Unnecessary Cast
        ([|(IIncrementable)|]y).Increment(); // Unnecessary Cast - OK

        Console.WriteLine(x.Value);
        Console.WriteLine(y.Value);
    }
}
",
 @"
using System;

interface IIncrementable
{
    int Value { get; }
    void Increment();
}

struct S : IIncrementable
{
    public int Value { get; private set; }
    public void Increment() { Value++; }
}

class C: IIncrementable
{
    public int Value { get; private set; }
    public void Increment() { Value++; }
}

static class Program
{
    static void Main()
    {
        Goo(new S(), new C());
    }

    static void Goo<TAny, TClass>(TAny x, TClass y)
        where TAny : IIncrementable
        where TClass : class, IIncrementable
    {
        ((IIncrementable)x).Increment(); // False Unnecessary Cast
        y.Increment(); // Unnecessary Cast - OK

        Console.WriteLine(x.Value);
        Console.WriteLine(y.Value);
    }
}
");
        }

        [WorkItem(545877, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545877")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotCrashOnIncompleteMethodDeclaration()
        {
            // This test has intentional syntax errors
            var source =
@"using System;

class A
{
    static void Main()
    {
        byte{|CS1001:|}{|CS1002:|}
        {|CS0411:Goo|}(x => 1, (byte)1);
    }

    static void Goo<T, S>(T x, {|CS1001:{|CS1031:)|}|}
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(46423, "https://github.com/dotnet/roslyn/issues/46423")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotCrashWhenTypeCantBeDetermined()
        {
            var source =
@"
class Other
{
    public short GetScopeIdForTelemetry(FixAllScope scope)
        => (short)(scope switch
        {
            FixAllScope.Document => 1,
            FixAllScope.Project => 2,
            FixAllScope.Solution => 3,
            _ => 4,
        });

    public enum FixAllScope
    {
        Document,
        Project,
        Solution,
        Other
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545777, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545777")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveImportantTrailingTrivia()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class Program
{
    static void Main()
    {
        long x =
#if true
            [|(long)|] // Remove Unnecessary Cast
#endif
            1;
    }
}
",

            @"
class Program
{
    static void Main()
    {
        long x =
#if true
            // Remove Unnecessary Cast
#endif
            1;
    }
}
");
        }

        [WorkItem(529791, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529791")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnnecessaryCastToNullable1()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class X
{
    static void Goo()
    {
        object x = [|(string)|]null;
        object y = [|(int?)|]null;
    }
}
",

            @"
class X
{
    static void Goo()
    {
        object x = null;
        object y = null;
    }
}
");
        }

        [WorkItem(545842, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545842")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnnecessaryCastToNullable2()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
static class C
{
    static void Main()
    {
        int? x = 1;
        long y = 2;
        long? z = x + [|(long?)|] y;
    }
}
",

            @"
static class C
{
    static void Main()
    {
        int? x = 1;
        long y = 2;
        long? z = x + y;
    }
}
");
        }

        [WorkItem(545850, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545850")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveSurroundingParentheses()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class Program
{
    static void Main()
    {
        int x = 1;
        ([|(int)|]x).ToString();
    }
}
",

            @"
class Program
{
    static void Main()
    {
        int x = 1;
        x.ToString();
    }
}
");
        }

        [WorkItem(529846, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529846")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastFromTypeParameterToObject()
        {
            var source =
@"class C
{
    static void Goo<T>(T x, object y)
    {
        if ((object)x == y)
        {
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545858, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545858")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastFromDelegateTypeToMulticastDelegate()
        {
            var source =
@"using System;

class C
{
    static void Main()
    {
        Action x = Console.WriteLine;
        Action y = Console.WriteLine;
        Console.WriteLine((MulticastDelegate)x == y);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545857, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545857")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInSizeOfArrayCreationExpression1()
        {
            // The cast below can't be removed because it would result in the implicit
            // conversion to int being called instead.

            var source =
@"using System;

class C
{
    static void Main()
    {
        Console.WriteLine(new int[(long)default(C)].Length);
    }

    public static implicit operator long(C x)
    {
        return 1;
    }

    public static implicit operator int(C x)
    {
        return 2;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545980, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545980")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInSizeOfArrayCreationExpression2()
        {
            // Array bounds must be an int, so the cast below can't be removed.

            var source =
@"class C
{
    static void Main()
    {
        var a = new int[(int)decimal.Zero];
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(529842, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529842")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInTernaryExpression()
        {
            var source =
@"using System;

class X
{
    public static implicit operator string(X x)
    {
        return x.ToString();
    }

    static void Main()
    {
        bool b = true;
        X x = new X();
        Console.WriteLine(b ? (string)null : x);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545882, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545882"), WorkItem(880752, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/880752")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastInConstructorInitializer1()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
class C
{
    C(int x) { }
    C() : this([|(int)|]1) { }
}
",

@"
class C
{
    C(int x) { }
    C() : this(1) { }
}
");
        }

        [WorkItem(545958, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545958"), WorkItem(880752, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/880752")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastInConstructorInitializer2()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System.Collections;

class C
{
    C(int x) { }
    C(object x) { }
    C() : this([|(IEnumerable)|]"""") { }
}
",

@"
using System.Collections;

class C
{
    C(int x) { }
    C(object x) { }
    C() : this("""") { }
}
");
        }

        [WorkItem(545957, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545957")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastInConstructorInitializer3()
        {
            var source =
@"class C
{
    C(int x)
    {
    }

    C() : this((long)1)
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                // /0/Test0.cs(7,16): error CS1503: Argument 1: cannot convert from 'long' to 'int'
                DiagnosticResult.CompilerError("CS1503").WithSpan(7, 16, 7, 23).WithArguments("1", "long", "int"),
                source);
        }

        [WorkItem(545842, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545842")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastToNullableInArithmeticExpression()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
static class C
{
    static void Main()
    {
        int? x = 1;
        long y = 2;
        long? z = x + [|(long?)|]y;
    }
}
",

@"
static class C
{
    static void Main()
    {
        int? x = 1;
        long y = 2;
        long? z = x + y;
    }
}
");
        }

        [WorkItem(545942, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545942")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastFromValueTypeToObjectInReferenceEquality()
        {
            // Note: The cast below can't be removed because it would result in an
            // illegal reference equality test between object and a value type.

            var source =
@"using System;

class Program
{
    static void Main()
    {
        object x = 1;
        Console.WriteLine(x == (object)1);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545962, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545962")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastWhenExpressionDoesntBind()
        {
            // Note: The cast below can't be removed because its expression doesn't bind.

            var source =
@"using System;

class Program
{
    static void Main()
    {
        ((IDisposable){|CS0103:x|}).Dispose();
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545944, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545944")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastBeforePointerDereference1()
        {
            // Note: The cast below can't be removed because it would result in *null,
            // which is illegal.

            var source =
@"unsafe class C
{
    int x = *(int*)null;
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545978, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545978")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastBeforePointerDereference2()
        {
            // Note: The cast below can't be removed because it would result in dereferencing
            // void*, which is illegal.

            var source =
@"unsafe class C
{
    static void Main()
    {
        void* p = null;
        int x = *(int*)p;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(2691, "https://github.com/dotnet/roslyn/issues/2691")]
        [WorkItem(2987, "https://github.com/dotnet/roslyn/issues/2987")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastBeforePointerDereference3()
        {
            // Conservatively disable cast simplifications for casts involving pointer conversions.
            // https://github.com/dotnet/roslyn/issues/2987 tracks improving cast simplification for this scenario.

            var source =
@"class C
{
    public unsafe float ReadSingle(byte* ptr)
    {
        return *(float*)ptr;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(2691, "https://github.com/dotnet/roslyn/issues/2691")]
        [WorkItem(2987, "https://github.com/dotnet/roslyn/issues/2987")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNumericCastInUncheckedExpression()
        {
            // Conservatively disable cast simplifications within explicit checked/unchecked expressions.
            // https://github.com/dotnet/roslyn/issues/2987 tracks improving cast simplification for this scenario.

            var source =
@"class C
{
    private unsafe readonly byte* _endPointer;
    private unsafe byte* _currentPointer;

    private unsafe void CheckBounds(int byteCount)
    {
        if (unchecked((uint)byteCount) > (_endPointer - _currentPointer))
        {
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(2691, "https://github.com/dotnet/roslyn/issues/2691")]
        [WorkItem(2987, "https://github.com/dotnet/roslyn/issues/2987")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNumericCastInUncheckedStatement()
        {
            // Conservatively disable cast simplifications within explicit checked/unchecked statements.
            // https://github.com/dotnet/roslyn/issues/2987 tracks improving cast simplification for this scenario.

            var source =
@"class C
{
    private unsafe readonly byte* _endPointer;
    private unsafe byte* _currentPointer;

    private unsafe void CheckBounds(int byteCount)
    {
        unchecked
        {
            if (((uint)byteCount) > (_endPointer - _currentPointer))
            {
            }
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(2691, "https://github.com/dotnet/roslyn/issues/2691")]
        [WorkItem(2987, "https://github.com/dotnet/roslyn/issues/2987")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNumericCastInCheckedExpression()
        {
            // Conservatively disable cast simplifications within explicit checked/unchecked expressions.
            // https://github.com/dotnet/roslyn/issues/2987 tracks improving cast simplification for this scenario.

            var source =
@"class C
{
    private unsafe readonly byte* _endPointer;
    private unsafe byte* _currentPointer;

    private unsafe void CheckBounds(int byteCount)
    {
        if (checked((uint)byteCount) > (_endPointer - _currentPointer))
        {
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(2691, "https://github.com/dotnet/roslyn/issues/2691")]
        [WorkItem(2987, "https://github.com/dotnet/roslyn/issues/2987")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNumericCastInCheckedStatement()
        {
            // Conservatively disable cast simplifications within explicit checked/unchecked statements.
            // https://github.com/dotnet/roslyn/issues/2987 tracks improving cast simplification for this scenario.

            var source =
@"class C
{
    private unsafe readonly byte* _endPointer;
    private unsafe byte* _currentPointer;

    private unsafe void CheckBounds(int byteCount)
    {
        checked
        {
            if (((uint)byteCount) > (_endPointer - _currentPointer))
            {
            }
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(26640, "https://github.com/dotnet/roslyn/issues/26640")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToByteFromIntInConditionalExpression()
        {
            var source =
@"class C
{
    object M1(bool b)
    {
        return b ? (byte)1 : (byte)0;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(26640, "https://github.com/dotnet/roslyn/issues/26640")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastToDoubleFromIntWithTwoInConditionalExpression()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"class C
{
    object M1(bool b)
    {
        return b ? [|(double)|]1 : [|(double)|]0;
    }
}",
@"class C
{
    object M1(bool b)
    {
        return b ? 1 : (double)0;
    }
}");
        }

        [WorkItem(26640, "https://github.com/dotnet/roslyn/issues/26640")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToDoubleFromIntInConditionalExpression()
        {
            var source =
@"class C
{
    object M1(bool b)
    {
        return b ? 1 : (double)0;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(26640, "https://github.com/dotnet/roslyn/issues/26640")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToUIntFromCharInConditionalExpression()
        {
            var source =
@"class C
{
    object M1(bool b)
    {
        return b ? '1' : (uint)'0';
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(26640, "https://github.com/dotnet/roslyn/issues/26640")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnnecessaryNumericCastToSameTypeInConditionalExpression()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"class C
{
    object M1(bool b)
    {
        return b ? [|(int)|]1 : 0;
    }
}",
@"class C
{
    object M1(bool b)
    {
        return b ? 1 : 0;
    }
}");
        }

        [WorkItem(545894, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545894")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInAttribute()
        {
            var source =
@"using System;

[A((byte)0)]
class A : Attribute
{
    public A(object x)
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(39042, "https://github.com/dotnet/roslyn/issues/39042")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastForImplicitNumericCastsThatLoseInformation()
        {
            var source =
@"using System;

class A
{
    public A(long x)
    {
        long y = (long)(double)x;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        #region Interface Casts

        [WorkItem(545889, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545889")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToInterfaceForUnsealedType()
        {
            // Note: The cast below can't be removed because X is not sealed.

            var source =
@"using System;

class X : IDisposable
{
    static void Main()
    {
        X x = new Y();
        ((IDisposable)x).Dispose();
    }

    public void Dispose()
    {
        Console.WriteLine(""X.Dispose"");
    }
}

class Y : X, IDisposable
{
    void IDisposable.Dispose()
    {
        Console.WriteLine(""Y.Dispose"");
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(34326, "https://github.com/dotnet/roslyn/issues/34326")]
        [WorkItem(545890, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545890")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToInterfaceForSealedType1()
        {
            var source =
@"
using System;

interface I
{
    void Goo(int x = 0);
}

sealed class C : I
{
    public void Goo(int x = 0)
    {
        Console.WriteLine(x);
    }

    static void Main()
    {
        ((I)new C()).Goo();
    }
}
";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(34326, "https://github.com/dotnet/roslyn/issues/34326")]
        [WorkItem(545890, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545890")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToInterfaceForSealedType2()
        {
            var source =
@"
using System;

interface I
{
    string Goo { get; }
}

sealed class C : I
{
    public string Goo
    {
        get
        {
            return ""Nikov Rules"";
        }
    }

    static void Main()
    {
        Console.WriteLine(((I)new C()).Goo);
    }
}
";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(34326, "https://github.com/dotnet/roslyn/issues/34326")]
        [WorkItem(545890, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545890")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToInterfaceForSealedType3()
        {
            var source =
@"
using System;

interface I
{
    string Goo { get; }
}

sealed class C : I
{
    public C Instance { get { return new C(); } }

    public string Goo
    {
        get
        {
            return ""Nikov Rules"";
        }
    }

    static void Main()
    {
        Console.WriteLine(((I)Instance).Goo);
    }
}
";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                // /0/Test0.cs(23,31): error CS0120: An object reference is required for the non-static field, method, or property 'C.Instance'
                DiagnosticResult.CompilerError("CS0120").WithSpan(23, 31, 23, 39).WithArguments("C.Instance"),
                source);
        }

        [WorkItem(545890, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545890")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToInterfaceForSealedType4()
        {
            var source =
@"using System;

interface I
{
    void Goo(int x = 0);
}

sealed class C : I
{
    public void Goo(int x = 1)
    {
        Console.WriteLine(x);
    }

    static void Main()
    {
        ((I)new C()).Goo();
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(34326, "https://github.com/dotnet/roslyn/issues/34326")]
        [WorkItem(545890, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545890")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToInterfaceForSealedType5()
        {
            var source =
@"
using System;

interface I
{
    void Goo(int x = 0);
}

sealed class C : I
{
    public void Goo(int x = 1)
    {
        Console.WriteLine(x);
    }

    static void Main()
    {
        ((I)new C()).Goo(2);
    }
}
";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545888, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545888")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToInterfaceForSealedType6()
        {
            // Note: The cast below can't be removed (even though C is sealed)
            // because the specified named arguments refer to parameters that
            // appear at different positions in the member signatures.

            var source =
@"using System;

interface I
{
    void Goo(int x = 0, int y = 0);
}

sealed class C : I
{
    public void Goo(int y = 0, int x = 0)
    {
        Console.WriteLine(x);
    }

    static void Main()
    {
        ((I)new C()).Goo(x: 1);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(34326, "https://github.com/dotnet/roslyn/issues/34326")]
        [WorkItem(545888, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545888")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToInterfaceForSealedType7()
        {
            var source =
@"
using System;

interface I
{
    int this[int x = 0, int y = 0] { get; }
}

sealed class C : I
{
    public int this[int x = 0, int y = 0]
    {
        get
        {
            return x * 2;
        }
    }

    static void Main()
    {
        Console.WriteLine(((I)new C())[x: 1]);
    }
}
";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545888, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545888")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToInterfaceForSealedType8()
        {
            // Note: The cast below can't be removed (even though C is sealed)
            // because the specified named arguments refer to parameters that
            // appear at different positions in the member signatures.

            var source =
@"using System;

interface I
{
    int this[int x = 0, int y = 0] { get; }
}

sealed class C : I
{
    public int this(int y = 0, int x = 0)
    {
        get
        {
            return x * 2;
        }
    }

    static void Main()
    {
        Console.WriteLine(((I)new C())[x: 1]);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                new[]
                {
                    // /0/Test0.cs(8,18): error CS0535: 'C' does not implement interface member 'I.this[int, int]'
                    DiagnosticResult.CompilerError("CS0535").WithSpan(8, 18, 8, 19).WithArguments("C", "I.this[int, int]"),
                    // /0/Test0.cs(10,16): error CS0548: 'C.this[(int y, ?), int]': property or indexer must have at least one accessor
                    DiagnosticResult.CompilerError("CS0548").WithSpan(10, 16, 10, 20).WithArguments("C.this[(int y, ?), int]"),
                    // /0/Test0.cs(10,20): error CS1003: Syntax error, '[' expected
                    DiagnosticResult.CompilerError("CS1003").WithSpan(10, 20, 10, 21).WithArguments("[", "("),
                    // /0/Test0.cs(10,27): error CS1750: A value of type 'int' cannot be used as a default parameter because there are no standard conversions to type '(int y, ?)'
                    DiagnosticResult.CompilerError("CS1750").WithSpan(10, 27, 10, 27).WithArguments("int", "(int y, ?)"),
                    // /0/Test0.cs(10,27): error CS1001: Identifier expected
                    DiagnosticResult.CompilerError("CS1001").WithSpan(10, 27, 10, 28),
                    // /0/Test0.cs(10,27): error CS1026: ) expected
                    DiagnosticResult.CompilerError("CS1026").WithSpan(10, 27, 10, 28),
                    // /0/Test0.cs(10,27): error CS8124: Tuple must contain at least two elements.
                    DiagnosticResult.CompilerError("CS8124").WithSpan(10, 27, 10, 28),
                    // /0/Test0.cs(10,41): error CS1003: Syntax error, ']' expected
                    DiagnosticResult.CompilerError("CS1003").WithSpan(10, 41, 10, 42).WithArguments("]", ")"),
                    // /0/Test0.cs(10,41): error CS1014: A get or set accessor expected
                    DiagnosticResult.CompilerError("CS1014").WithSpan(10, 41, 10, 42),
                    // /0/Test0.cs(10,41): error CS1514: { expected
                    DiagnosticResult.CompilerError("CS1514").WithSpan(10, 41, 10, 42),
                    // /0/Test0.cs(10,42): error CS1014: A get or set accessor expected
                    DiagnosticResult.CompilerError("CS1014").WithSpan(10, 42, 10, 42),
                    // /0/Test0.cs(12,12): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(12, 12, 12, 12),
                    // /0/Test0.cs(16,6): error CS1513: } expected
                    DiagnosticResult.CompilerError("CS1513").WithSpan(16, 6, 16, 6),
                },
                source);
        }

        [WorkItem(545883, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545883")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToInterfaceForSealedType9()
        {
            // Note: The cast below can't be removed (even though C is sealed)
            // because it would result in binding to a Dispose method that doesn't
            // implement IDisposable.Dispose().

            var source =
@"using System;
using System.IO;

sealed class C : MemoryStream
{
    static void Main()
    {
        C s = new C();
        ((IDisposable)s).Dispose();
    }

    new public void Dispose()
    {
        Console.WriteLine(""new Dispose()"");
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545887, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545887")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToInterfaceForStruct1()
        {
            // Note: The cast below can't be removed because the cast boxes 's' and
            // unboxing would change program behavior.

            var source =
@"using System;

interface IIncrementable
{
    int Value { get; }

    void Increment();
}

struct S : IIncrementable
{
    public int Value { get; private set; }

    public void Increment()
    {
        Value++;
    }

    static void Main()
    {
        var s = new S();
        ((IIncrementable)s).Increment();
        Console.WriteLine(s.Value);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(34326, "https://github.com/dotnet/roslyn/issues/34326")]
        [WorkItem(545834, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545834")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastToInterfaceForStruct2()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        ([|(IDisposable)|]GetEnumerator()).Dispose();
    }

    static List<int>.Enumerator GetEnumerator()
    {
        var x = new List<int> { 1, 2, 3 };
        return x.GetEnumerator();
    }
}
",
@"
using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        GetEnumerator().Dispose();
    }

    static List<int>.Enumerator GetEnumerator()
    {
        var x = new List<int> { 1, 2, 3 };
        return x.GetEnumerator();
    }
}
");
        }

        [WorkItem(544655, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/544655")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastToICloneableForDelegate()
        {
            // Note: The cast below can be removed because delegates are implicitly
            // sealed.

            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;

class C
{
    static void Main()
    {
        Action a = () => { };
        var c = ([|(ICloneable)|]a).Clone();
    }
}
",

@"
using System;

class C
{
    static void Main()
    {
        Action a = () => { };
        var c = a.Clone();
    }
}
");
        }

        [WorkItem(545926, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545926")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastToICloneableForArray()
        {
            // Note: The cast below can be removed because arrays are implicitly
            // sealed.

            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;

class C
{
    static void Main()
    {
        var a = new[] { 1, 2, 3 };
        var c = ([|(ICloneable)|]a).Clone();
    }
}
",

@"
using System;

class C
{
    static void Main()
    {
        var a = new[] { 1, 2, 3 };
        var c = a.Clone();
    }
}
");
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastToInterfaceForString()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;
using System.Collections.Generic;

class C
{
    static void Main(string s)
    {
        IEnumerable<char> i = [|(IEnumerable<char>)|]s;
    }
}
",

@"
using System;
using System.Collections.Generic;

class C
{
    static void Main(string s)
    {
        IEnumerable<char> i = s;
    }
}
");
        }

        [WorkItem(529897, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529897")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastToIConvertibleForEnum()
        {
            // Note: The cast below can be removed because enums are implicitly
            // sealed.

            await VerifyCS.VerifyCodeFixAsync(
            @"
using System;

class Program
{
    static void Main()
    {
        Enum e = DayOfWeek.Monday;
        var y = ([|(IConvertible)|]e).GetTypeCode();
    }
}
",

@"
using System;

class Program
{
    static void Main()
    {
        Enum e = DayOfWeek.Monday;
        var y = e.GetTypeCode();
    }
}
");
        }

        #endregion

        #region ParamArray Parameter Casts

        [WorkItem(545141, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545141")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToObjectInParamArrayArg1()
        {
            var source =
@"using System;

class C
{
    static void Main()
    {
        Goo((object)null);
    }

    static void Goo(params object[] x)
    {
        Console.WriteLine(x.Length);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(529911, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529911")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToIntArrayInParamArrayArg2()
        {
            var source =
@"using System;

class C
{
    static void Main()
    {
        Goo((int[])null);
    }

    static void Goo(params object[] x)
    {
        Console.WriteLine(x.Length);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(529911, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529911")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToObjectArrayInParamArrayArg3()
        {
            var source =
@"using System;

class C
{
    static void Main()
    {
        Goo((object[])null);
    }

    static void Goo(params object[][] x)
    {
        Console.WriteLine(x.Length);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(529911, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529911")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastToObjectArrayInParamArrayArg1()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class C
{
    static void Goo(params object[] x) { }

    static void Main()
    {
        Goo([|(object[])|]null);
    }
}
",

@"
class C
{
    static void Goo(params object[] x) { }

    static void Main()
    {
        Goo(null);
    }
}
");
        }

        [WorkItem(529911, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529911")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastToStringArrayInParamArrayArg2()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class C
{
    static void Goo(params object[] x) { }

    static void Main()
    {
        Goo([|(string[])|]null);
    }
}
",

@"
class C
{
    static void Goo(params object[] x) { }

    static void Main()
    {
        Goo(null);
    }
}
");
        }

        [WorkItem(529911, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529911")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastToIntArrayInParamArrayArg3()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class C
{
    static void Goo(params int[] x) { }

    static void Main()
    {
        Goo([|(int[])|]null);
    }
}
",

@"
class C
{
    static void Goo(params int[] x) { }

    static void Main()
    {
        Goo(null);
    }
}
");
        }

        [WorkItem(529911, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529911")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastToObjectArrayInParamArrayArg4()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class C
{
    static void Goo(params object[] x) { }

    static void Main()
    {
        Goo([|(object[])|]null, null);
    }
}
",

@"
class C
{
    static void Goo(params object[] x) { }

    static void Main()
    {
        Goo(null, null);
    }
}
");
        }

        [WorkItem(529911, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529911")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastToObjectInParamArrayArg5()
        {
            await VerifyCS.VerifyCodeFixAsync(
            @"
class C
{
    static void Goo(params object[] x) { }

    static void Main()
    {
        Goo([|(object)|]null, null);
    }
}
",

@"
class C
{
    static void Goo(params object[] x) { }

    static void Main()
    {
        Goo(null, null);
    }
}
");
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastToObjectArrayInParamArrayWithNamedArgument()
        {
            await VerifyCS.VerifyCodeFixAsync(
                @"
class C
{
    static void Main()
    {
        Goo(x: [|(object[])|]null);
    }

    static void Goo(params object[] x) { }
}
",
                @"
class C
{
    static void Main()
    {
        Goo(x: null);
    }

    static void Goo(params object[] x) { }
}
");
        }

        #endregion

        #region ForEach Statements

        [WorkItem(545961, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545961")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInForEach1()
        {
            // The cast below can't be removed because it would result an error
            // in the foreach statement.

            var source =
@"using System.Collections;

class Program
{
    static void Main()
    {
        object s = "";
        foreach (object x in (IEnumerable)s)
        {
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                new[]
                {
                    // /0/Test0.cs(7,20): error CS1010: Newline in constant
                    DiagnosticResult.CompilerError("CS1010").WithSpan(7, 20, 7, 20),
                    // /0/Test0.cs(7,22): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(7, 22, 7, 22),
                },
                source);
        }

        [WorkItem(545961, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545961")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInForEach2()
        {
            // The cast below can't be removed because it would result an error
            // in the foreach statement.

            var source =
@"using System.Collections.Generic;

class Program
{
    static void Main()
    {
        object s = "";
        foreach (object x in (IEnumerable<char>)s)
        {
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                new[]
                {
                    // /0/Test0.cs(7,20): error CS1010: Newline in constant
                    DiagnosticResult.CompilerError("CS1010").WithSpan(7, 20, 7, 20),
                    // /0/Test0.cs(7,22): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(7, 22, 7, 22),
                },
                source);
        }

        [WorkItem(545961, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545961")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInForEach3()
        {
            // The cast below can't be removed because it would result an error
            // in the foreach statement since C doesn't contain a GetEnumerator()
            // method.

            var source =
@"using System.Collections;

class D
{
    public IEnumerator GetEnumerator()
    {
        yield return 1;
    }
}

class C
{
    public static implicit operator D(C c)
    {
        return new D();
    }

    static void Main()
    {
        object s = "";
        foreach (object x in (D)new C())
        {
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                new[]
                {
                    // /0/Test0.cs(20,20): error CS1010: Newline in constant
                    DiagnosticResult.CompilerError("CS1010").WithSpan(20, 20, 20, 20),
                    // /0/Test0.cs(20,22): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(20, 22, 20, 22),
                },
                source);
        }

        [WorkItem(545961, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545961")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInForEach4()
        {
            // The cast below can't be removed because it would result in
            // C.GetEnumerator() being called rather than D.GetEnumerator().

            var source =
@"using System;
using System.Collections;

class D
{
    public IEnumerator GetEnumerator()
    {
        yield return 1;
    }
}

class C
{
    public IEnumerator GetEnumerator()
    {
        yield return 2;
    }

    public static implicit operator D(C c)
    {
        return new D();
    }

    static void Main()
    {
        object s = "";
        foreach (object x in (D)new C())
        {
            Console.WriteLine(x);
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                new[]
                {
                    // /0/Test0.cs(26,20): error CS1010: Newline in constant
                    DiagnosticResult.CompilerError("CS1010").WithSpan(26, 20, 26, 20),
                    // /0/Test0.cs(26,22): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(26, 22, 26, 22),
                },
                source);
        }

        [WorkItem(545961, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545961")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInForEach5()
        {
            // The cast below can't be removed because it would change the
            // type of 'x'.

            var source =
@"using System;

class Program
{
    static void Main()
    {
        string[] s = {
            ""A""
        };
        foreach (var x in (Array)s)
        {
            var y = x;
            y = 1;
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        #endregion

        [WorkItem(545925, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545925")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastIfOverriddenMethodHasIncompatibleParameterList()
        {
            // Note: The cast below can't be removed because the parameter list
            // of Goo and its override have different default values.

            var source =
@"using System;

abstract class Y
{
    public abstract void Goo(int x = 1);
}

class X : Y
{
    static void Main()
    {
        ((Y)new X()).Goo();
    }

    public override void Goo(int x = 2)
    {
        Console.WriteLine(x);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545925, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545925")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastIfOverriddenMethodHaveCompatibleParameterList()
        {
            // Note: The cast below can be removed because the parameter list
            // of Goo and its override have the same default values.

            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

abstract class Y
{
    public abstract void Goo(int x = 1);
}

class X : Y
{
    static void Main()
    {
        ([|(Y)|]new X()).Goo();
    }

    public override void Goo(int x = 1)
    {
        Console.WriteLine(x);
    }
}
",

@"
using System;

abstract class Y
{
    public abstract void Goo(int x = 1);
}

class X : Y
{
    static void Main()
    {
        new X().Goo();
    }

    public override void Goo(int x = 1)
    {
        Console.WriteLine(x);
    }
}
");
        }

        [WorkItem(529916, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529916")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastInReceiverForMethodGroup()
        {
            // Note: The cast below can be removed because the it results in
            // the same method group.

            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

static class Program
{
    static void Main()
    {
        Action a = ([|(string)|]"""").Goo;
    }

    static void Goo(this string x) { }
}
",

@"
using System;

static class Program
{
    static void Main()
    {
        Action a = """".Goo;
    }

    static void Goo(this string x) { }
}
");
        }

        [WorkItem(609497, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/609497")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task Bugfix_609497()
        {
            var source =
@"using System;
using System.Threading.Tasks;

class Program
{
    static void Main()
    {
        Goo().Wait();
    }

    static async Task Goo()
    {
        Task task = Task.FromResult(0);
        Console.WriteLine(await (dynamic)task);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545995, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545995")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToDifferentTypeWithSameName()
        {
            // Note: The cast below cannot be removed because the it results in
            // a different overload being picked.

            var source =
@"using System;
using MyInt = System.Int32;

namespace System
{
    public struct Int32
    {
        public static implicit operator Int32(int x)
        {
            return default(Int32);
        }
    }
}

class A
{
    static void Goo(int x)
    {
        Console.WriteLine(""int"");
    }

    static void Goo(MyInt x)
    {
        Console.WriteLine(""MyInt"");
    }

    static void Main()
    {
        Goo((MyInt)0);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545921, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545921")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastWhichWouldChangeAttributeOverloadResolution1()
        {
            // Note: The cast below cannot be removed because it would result in
            // a different attribute constructor being picked

            var source =
@"using System;

[Flags]
enum EEEnum
{
    Flag1 = 0x2,
    Flag2 = 0x1,
}

class MyAttributeAttribute : Attribute
{
    public MyAttributeAttribute(EEEnum e)
    {
    }

    public MyAttributeAttribute(short e)
    {
    }

    public void Goo(EEEnum e)
    {
    }

    public void Goo(short e)
    {
    }

    [MyAttribute((EEEnum)0x0)]
    public void Bar()
    {
        Goo((EEEnum)0x0);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(608180, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/608180")]
        [WorkItem(624252, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/624252")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastIfArgumentIsRestricted_TypedReference()
        {
            var source =
@"using System;

class Program
{
    static void Main(string[] args)
    {
    }

    static void v(dynamic x)
    {
        var y = default(TypedReference);
        dd((object)x, y);
    }

    static void dd(object obj, TypedReference d)
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(627107, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/627107")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnArgumentsWithOtherDynamicArguments()
        {
            var source =
@"using System;

class Program
{
    static void Main()
    {
        C<string>.InvokeGoo(0);
    }
}

class C<T>
{
    public static void InvokeGoo(dynamic x)
    {
        Console.WriteLine(Goo(x, (object)"""", """"));
    }

    static void Goo(int x, string y, T z)
    {
    }

    static bool Goo(int x, object y, object z)
    {
        return true;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(627107, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/627107")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnArgumentsWithOtherDynamicArguments_Bracketed()
        {
            var source =
@"class C<T>
{
    int this[int x, T s, string d = ""abc""]
    {
        get
        {
            return 0;
        }

        set
        {
        }
    }

    int this[int x, object s, object d]
    {
        get
        {
            return 0;
        }

        set
        {
        }
    }

    void Goo(dynamic xx)
    {
        var y = this[x: xx, s: """", d: (object)""""];
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(627107, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/627107")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnArgumentsWithDynamicReceiverOpt()
        {
            var source =
@"class C
{
    static bool Goo(dynamic d)
    {
        d((object)"""");
        return true;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(627107, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/627107")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnArgumentsWithDynamicReceiverOpt_1()
        {
            var source =
@"class C
{
    static bool Goo(dynamic d)
    {
        d.goo((object)"""");
        return true;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(627107, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/627107")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnArgumentsWithDynamicReceiverOpt_2()
        {
            var source =
@"class C
{
    static bool Goo(dynamic d)
    {
        d.goo.bar.goo((object)"""");
        return true;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(627107, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/627107")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnArgumentsWithDynamicReceiverOpt_3()
        {
            var source =
@"class C
{
    static bool Goo(dynamic d)
    {
        d.goo().bar().goo((object)"""");
        return true;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(627107, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/627107")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnArgumentsWithOtherDynamicArguments_1()
        {
            var source =
@"using System;

class Program
{
    static void Main()
    {
        C<string>.InvokeGoo(0);
    }
}

class C<T>
{
    public static void InvokeGoo(dynamic x)
    {
        Console.WriteLine(Goo((object)"""", x, """"));
    }

    static void Goo(string y, int x, T z)
    {
    }

    static bool Goo(object y, int x, object z)
    {
        return true;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(545998, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/545998")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastWhichWouldChangeAttributeOverloadResolution2()
        {
            // Note: The cast below cannot be removed because it would result in
            // a different attribute constructor being picked

            var source =
@"using System;

[A(new[] { (long)0 })]
class A : Attribute
{
    public A(long[] x)
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(529894, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529894")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotUnnecessaryCastFromEnumToUint()
        {
            var source =
@"using System;

enum E
{
    X = -1
}

class C
{
    static void Main()
    {
        E x = E.X;
        Console.WriteLine((uint)x > 0);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(529846, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529846")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotUnnecessaryCastFromTypeParameterToObject()
        {
            var source =
@"class C
{
    static void Goo<T>(T x, object y)
    {
        if ((object)x == y)
        {
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(640136, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/640136")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnnecessaryCastAndParseCorrect()
        {
            var source =
@"
using System;
using System.Threading.Tasks;

class C
{
    void Goo(Task<Action> x)
    {
        (([|(Task<Action>)|]x).Result)();
    }
}
";
            var fixedSource =
@"
using System;
using System.Threading.Tasks;

class C
{
    void Goo(Task<Action> x)
    {
        (x.Result)();
    }
}
";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedState =
                {
                    Sources = { fixedSource },
                    ExpectedDiagnostics =
                    {
                        // /0/Test0.cs(9,10): error CS0118: 'x' is a variable but is used like a type
                        DiagnosticResult.CompilerError("CS0118").WithSpan(9, 10, 9, 11),
                        // /0/Test0.cs(9,20): error CS1525: Invalid expression term ')'
                        DiagnosticResult.CompilerError("CS1525").WithSpan(9, 20, 9, 21).WithArguments(")"),
                    },
                },
                // The code fix in this case does not produce valid code or a valid syntax tree
                CodeActionValidationMode = CodeActionValidationMode.None,
            }.RunAsync();
        }

        [WorkItem(626026, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/626026")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastIfUserDefinedExplicitCast()
        {
            var source =
@"class Program
{
    static void Main(string[] args)
    {
        B bar = new B();
        A a = (A)bar;
    }
}

public struct A
{
    public static explicit operator A(B b)
    {
        return new A();
    }
}

public struct B
{
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(768895, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/768895")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInTernary()
        {
            var source =
@"class Program
{
    static void Main(string[] args)
    {
        object x = null;
        int y = (bool)x ? 1 : 0;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(770187, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/770187")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInSwitchExpression()
        {
            var source =
@"namespace ConsoleApplication23
{
    class Program
    {
        static void Main(string[] args)
        {
            int goo = 0;
            switch ((E)goo)
            {
                case E.A:
                case E.B:
                    return;
            }
        }
    }

    enum E
    {
        A,
        B,
        C
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(844482, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/844482")]
        [WorkItem(2761, "https://github.com/dotnet/roslyn/issues/2761")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastFromBaseToDerivedWithExplicitReference()
        {
            var source =
@"class Program
{
    static void Main(string[] args)
    {
        C x = null;
        C y = null;
        y = (D)x;
    }
}

class C
{
}

class D : C
{
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(3254, "https://github.com/dotnet/roslyn/issues/3254")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToTypeParameterWithExceptionConstraint()
        {
            var source =
@"using System;

class Program
{
    private static void RequiresCondition<TException>(bool condition, string messageOnFalseCondition) where TException : Exception
    {
        if (!condition)
        {
            throw (TException)Activator.CreateInstance(typeof(TException), messageOnFalseCondition);
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(3254, "https://github.com/dotnet/roslyn/issues/3254")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastToTypeParameterWithExceptionSubTypeConstraint()
        {
            var source =
@"using System;

class Program
{
    private static void RequiresCondition<TException>(bool condition, string messageOnFalseCondition) where TException : ArgumentException
    {
        if (!condition)
        {
            throw (TException)Activator.CreateInstance(typeof(TException), messageOnFalseCondition);
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(8111, "https://github.com/dotnet/roslyn/issues/8111")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastThatChangesShapeOfAnonymousTypeObject()
        {
            var source =
@"class Program
{
    static void Main(string[] args)
    {
        object thing = new { shouldBeAnInt = (int)Directions.South };
    }

    public enum Directions
    {
        North,
        East,
        South,
        West
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(8111, "https://github.com/dotnet/roslyn/issues/8111")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastThatDoesntChangeShapeOfAnonymousTypeObject()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"class Program
{
    static void Main(string[] args)
    {
        object thing = new { shouldBeAnInt = [|(Directions)|]Directions.South };
    }

    public enum Directions
    {
        North,
        East,
        South,
        West
    }
}",

@"class Program
{
    static void Main(string[] args)
    {
        object thing = new { shouldBeAnInt = Directions.South };
    }

    public enum Directions
    {
        North,
        East,
        South,
        West
    }
}");
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task Tuple()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"class C
{
    void Main()
    {
        (int, string) tuple = [|((int, string))|](1, ""hello"");
    }
}",
@"class C
{
    void Main()
    {
        (int, string) tuple = (1, ""hello"");
    }
}");
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TupleWithDifferentNames()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"class C
{
    void Main()
    {
        (int a, string) tuple = [|((int, string d))|](1, f: ""hello"");
    }
}",
@"class C
{
    void Main()
    {
        (int a, string) tuple = (1, f: ""hello"");
    }
}");
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        [WorkItem(24791, "https://github.com/dotnet/roslyn/issues/24791")]
        public async Task SimpleBoolCast()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"class C
{
    bool M()
    {
        if (![|(bool)|]M()) throw null;
        throw null;
    }
}",
@"class C
{
    bool M()
    {
        if (!M()) throw null;
        throw null;
    }
}");
        }

        [WorkItem(12572, "https://github.com/dotnet/roslyn/issues/12572")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastThatUnboxes()
        {
            // The cast below can't be removed because it could throw a null ref exception.
            var source =
@"using System;

class Program
{
    static void Main()
    {
        object i = null;
        switch ((int)i)
        {
            case 0:
                Console.WriteLine(0);
                break;
            case 1:
                Console.WriteLine(1);
                break;
            case 2:
                Console.WriteLine(2);
                break;
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(17029, "https://github.com/dotnet/roslyn/issues/17029")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnEnumComparison1()
        {
            var source =
@"
enum TransferTypeKey
{
    Transfer,
    TransferToBeneficiary
}

class Program
{
    static void Main(dynamic p)
    {
        if (p.TYP != (int)TransferTypeKey.TransferToBeneficiary)
          throw new InvalidOperationException();
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                // /0/Test0.cs(13,21): error CS0246: The type or namespace name 'InvalidOperationException' could not be found (are you missing a using directive or an assembly reference?)
                DiagnosticResult.CompilerError("CS0246").WithSpan(13, 21, 13, 46).WithArguments("InvalidOperationException"),
                source);
        }

        [WorkItem(17029, "https://github.com/dotnet/roslyn/issues/17029")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnEnumComparison2()
        {
            var source =
@"
enum TransferTypeKey
{
    Transfer,
    TransferToBeneficiary
}

class Program
{
    static void Main(dynamic p)
    {
        if ((int)TransferTypeKey.TransferToBeneficiary != p.TYP)
          throw new InvalidOperationException();
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                // /0/Test0.cs(13,21): error CS0246: The type or namespace name 'InvalidOperationException' could not be found (are you missing a using directive or an assembly reference?)
                DiagnosticResult.CompilerError("CS0246").WithSpan(13, 21, 13, 46).WithArguments("InvalidOperationException"),
                source);
        }

        [WorkItem(18978, "https://github.com/dotnet/roslyn/issues/18978")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnCallToMethodWithParamsArgs()
        {
            var source =
@"
class Program
{
    public static void Main(string[] args)
    {
        var takesArgs = new[] { ""Hello"", ""World"" };
        TakesParams((object)takesArgs);
    }

    private static void TakesParams(params object[] goo)
    {
        Console.WriteLine(goo.Length);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                // /0/Test0.cs(12,9): error CS0103: The name 'Console' does not exist in the current context
                DiagnosticResult.CompilerError("CS0103").WithSpan(12, 9, 12, 16).WithArguments("Console"),
                source);
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnCallToMethodWithParamsArgsWithIncorrectMethodDefintion()
        {
            var source =
@"
class Program
{
    public static void Main(string[] args)
    {
        TakesParams((string)null);
    }

    private static void TakesParams({|CS0225:params|} string wrongDefined)
    {
        Console.WriteLine(wrongDefined.Length);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                // /0/Test0.cs(11,9): error CS0103: The name 'Console' does not exist in the current context
                DiagnosticResult.CompilerError("CS0103").WithSpan(11, 9, 11, 16).WithArguments("Console"),
                source);
        }

        [WorkItem(18978, "https://github.com/dotnet/roslyn/issues/18978")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastOnCallToMethodWithParamsArgsIfImplicitConversionExists()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
class Program
{
    public static void Main(string[] args)
    {
        var takesArgs = new[] { ""Hello"", ""World"" };
        TakesParams([|(System.IComparable[])|]takesArgs);
    }

    private static void TakesParams(params object[] goo)
    {
        System.Console.WriteLine(goo.Length);
    }
}",
@"
class Program
{
    public static void Main(string[] args)
    {
        var takesArgs = new[] { ""Hello"", ""World"" };
        TakesParams(takesArgs);
    }

    private static void TakesParams(params object[] goo)
    {
        System.Console.WriteLine(goo.Length);
    }
}");
        }

        [WorkItem(20630, "https://github.com/dotnet/roslyn/issues/20630")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnCallToAttributeWithParamsArgs()
        {
            var source =
@"
using System;
using System.Reflection;

sealed class MarkAttribute : Attribute
{
  public readonly string[] Arr;

  public MarkAttribute(params string[] arr)
  {
    Arr = arr;
  }
}
[Mark((string)null)]   // wrong instance of: IDE0004 Cast is redundant.
static class Program
{
  static void Main()
  {
  }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(29264, "https://github.com/dotnet/roslyn/issues/29264")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnDictionaryIndexer()
        {
            var source =
@"
using System;
using System.Reflection;
using System.Collections.Generic;

static class Program
{
    enum TestEnum
    {
        Test,
    }

    static void Main()
    {
        Dictionary<int, string> Icons = new Dictionary<int, string>
        {
            [(int) TestEnum.Test] = null,
        };
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(29264, "https://github.com/dotnet/roslyn/issues/29264")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastOnDictionaryIndexer()
        {
            await VerifyCS.VerifyCodeFixAsync(
                @"
using System;
using System.Reflection;
using System.Collections.Generic;

static class Program
{
    enum TestEnum
    {
        Test,
    }

    static void Main()
    {
        Dictionary<int, string> Icons = new Dictionary<int, string>
        {
            [[|(int)|] 0] = null,
        };
    }
}",
                @"
using System;
using System.Reflection;
using System.Collections.Generic;

static class Program
{
    enum TestEnum
    {
        Test,
    }

    static void Main()
    {
        Dictionary<int, string> Icons = new Dictionary<int, string>
        {
            [0] = null,
        };
    }
}");
        }

        [WorkItem(20630, "https://github.com/dotnet/roslyn/issues/20630")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnCallToAttributeWithParamsArgsAndProperty()
        {
            var source =
@"
using System;
sealed class MarkAttribute : Attribute
{
    public MarkAttribute(params string[] arr)
    {
    }
    public int Prop { get; set; }
}

[Mark((string)null, Prop = 1)]
static class Program
{
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20630, "https://github.com/dotnet/roslyn/issues/20630")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnCallToAttributeWithParamsArgsPropertyAndOtherArg()
        {
            var source =
@"
using System;
sealed class MarkAttribute : Attribute
{
    public MarkAttribute(bool otherArg, params string[] arr)
    {
    }
    public int Prop { get; set; }
}

[Mark(true, (string)null, Prop = 1)]
static class Program
{
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20630, "https://github.com/dotnet/roslyn/issues/20630")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnCallToAttributeWithParamsArgsNamedArgsAndProperty()
        {
            var source =
@"
using System;
sealed class MarkAttribute : Attribute
{
    public MarkAttribute(bool otherArg, params string[] arr)
    {
    }
    public int Prop { get; set; }
}

[Mark(arr: (string)null, otherArg: true, Prop = 1)]
static class Program
{
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20630, "https://github.com/dotnet/roslyn/issues/20630")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnCallToAttributeWithParamsArgsNamedArgsWithIncorrectMethodDefintion()
        {
            var source =
@"
using System;
sealed class MarkAttribute : Attribute
{
    public MarkAttribute(bool otherArg, {|CS0225:params|} string wrongDefined)
    {
    }
    public int Prop { get; set; }
}

[Mark(true, (string)null, Prop = 1)]
static class Program
{
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20630, "https://github.com/dotnet/roslyn/issues/20630")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastOnCallToAttributeWithParamsArgsWithImplicitCast()
        {
            var source =
@"
using System;
sealed class MarkAttribute : Attribute
{
    public MarkAttribute(bool otherArg, params object[] arr)
    {
    }
    public int Prop { get; set; }
}

[Mark(arr: [|(object[])|]new[] { ""Hello"", ""World"" }, otherArg: true, Prop = 1)]
static class Program
{
}";
            var fixedSource =
@"
using System;
sealed class MarkAttribute : Attribute
{
    public MarkAttribute(bool otherArg, params object[] arr)
    {
    }
    public int Prop { get; set; }
}

[Mark(arr: (new[] { ""Hello"", ""World"" }), otherArg: true, Prop = 1)]
static class Program
{
}";

            await new VerifyCS.Test
            {
                TestState =
                {
                    Sources = { source },
                    ExpectedDiagnostics =
                    {
                        // /0/Test0.cs(11,2): error CS0182: An attribute argument must be a constant expression, typeof expression or array creation expression of an attribute parameter type
                        DiagnosticResult.CompilerError("CS0182").WithSpan(11, 2, 11, 75),
                    },
                },
                FixedState =
                {
                    Sources = { fixedSource },
                    ExpectedDiagnostics =
                    {
                        // /0/Test0.cs(11,2): error CS0182: An attribute argument must be a constant expression, typeof expression or array creation expression of an attribute parameter type
                        DiagnosticResult.CompilerError("CS0182").WithSpan(11, 2, 11, 67),
                    },
                },
            }.RunAsync();
        }

        [WorkItem(20630, "https://github.com/dotnet/roslyn/issues/20630")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastOnCallToAttributeWithCastInPropertySetter()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System;
sealed class MarkAttribute : Attribute
{
    public MarkAttribute()
    {
    }
    public int Prop { get; set; }
}

[Mark(Prop = [|(int)|]1)]
static class Program
{
}",
@"
using System;
sealed class MarkAttribute : Attribute
{
    public MarkAttribute()
    {
    }
    public int Prop { get; set; }
}

[Mark(Prop = 1)]
static class Program
{
}");
        }

        [WorkItem(18510, "https://github.com/dotnet/roslyn/issues/18510")]
        [Theory, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        [InlineData("-")]
        [InlineData("+")]
        public async Task DoNotRemoveCastOnInvalidUnaryOperatorEnumValue1(string op)
        {
            var source =
$@"
enum Sign
    {{
        Positive = 1,
        Negative = -1
    }}

    class T
    {{
        void Goo()
        {{
            Sign mySign = Sign.Positive;
            Sign invertedSign = (Sign) ( {op}((int) mySign) );
        }}
    }}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(18510, "https://github.com/dotnet/roslyn/issues/18510")]
        [Theory, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        [InlineData("-")]
        [InlineData("+")]
        public async Task DoNotRemoveCastOnInvalidUnaryOperatorEnumValue2(string op)
        {
            var source =
$@"
enum Sign
    {{
        Positive = 1,
        Negative = -1
    }}

    class T
    {{
        void Goo()
        {{
            Sign mySign = Sign.Positive;
            Sign invertedSign = (Sign) ( {op}(int) mySign );
        }}
    }}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(18510, "https://github.com/dotnet/roslyn/issues/18510")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastOnValidUnaryOperatorEnumValue()
        {
            var source =
@"
enum Sign
    {
        Positive = 1,
        Negative = -1
    }

    class T
    {
        void Goo()
        {
            Sign mySign = Sign.Positive;
            Sign invertedSign = (Sign) ( ~[|(int)|] mySign );
        }
    }";
            var fixedSource =
@"
enum Sign
    {
        Positive = 1,
        Negative = -1
    }

    class T
    {
        void Goo()
        {
            Sign mySign = Sign.Positive;
            Sign invertedSign = [|(Sign)|] ( ~mySign);
        }
    }";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedState =
                {
                    Sources = { fixedSource },
                    MarkupHandling = MarkupMode.Allow,
                },
                CodeFixTestBehaviors = CodeFixTestBehaviors.FixOne,
            }.RunAsync();
        }

        [WorkItem(18510, "https://github.com/dotnet/roslyn/issues/18510")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveCastOnValidUnaryOperatorEnumValue_Nullable()
        {
            var source =
@"
enum Sign
    {
        Positive = 1,
        Negative = -1
    }

    class T
    {
        void Goo()
        {
            Sign mySign = Sign.Positive;
            Sign? invertedSign = (Sign?)(~[|(int)|] mySign);
        }
    }";
            var fixedSource =
@"
enum Sign
    {
        Positive = 1,
        Negative = -1
    }

    class T
    {
        void Goo()
        {
            Sign mySign = Sign.Positive;
            Sign? invertedSign = (Sign?)(~mySign);
        }
    }";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = fixedSource,
            }.RunAsync();
        }

        [WorkItem(18510, "https://github.com/dotnet/roslyn/issues/18510")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveEnumCastToDifferentRepresentation()
        {
            var source =
@"
enum Sign
    {
        Positive = 1,
        Negative = -1
    }

    class T
    {
        void Goo()
        {
            Sign mySign = Sign.Positive;
            Sign invertedSign = (Sign) ( ~(long) mySign );
        }
    }";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = source,
            }.RunAsync();
        }

        [WorkItem(25456, "https://github.com/dotnet/roslyn/issues/25456#issuecomment-373549735")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotIntroduceDefaultLiteralInSwitchCase()
        {
            var source =
@"
class C
{
    void M()
    {
        switch (true)
        {
            case (bool)default:
                break;
        }
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp7_1,
            }.RunAsync();
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotIntroduceDefaultLiteralInSwitchCase_CastInsideParentheses()
        {
            var source =
@"
class C
{
    void M()
    {
        switch (true)
        {
            case ((bool)default):
                break;
        }
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp7_1,
            }.RunAsync();
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotIntroduceDefaultLiteralInSwitchCase_DefaultInsideParentheses()
        {
            var source =
@"
class C
{
    void M()
    {
        switch (true)
        {
            case (bool)(default):
                break;
        }
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp7_1,
            }.RunAsync();
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotIntroduceDefaultLiteralInSwitchCase_RemoveDoubleCast()
        {
            var source =
@"
class C
{
    void M()
    {
        switch (true)
        {
            case [|(bool)|][|(bool)|]default:
                break;
        }
    }
}";
            var fixedSource =
@"
class C
{
    void M()
    {
        switch (true)
        {
            case (bool)default:
                break;
        }
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = fixedSource,
                LanguageVersion = LanguageVersion.CSharp7_1,
            }.RunAsync();
        }

        [WorkItem(12631, "https://github.com/dotnet/roslyn/issues/12631")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveRedundantBoolCast()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
class C
{
    void M()
    {
        var a = true;
        var b = ![|(bool)|]a;
    }
}",
@"
class C
{
    void M()
    {
        var a = true;
        var b = !a;
    }
}");
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotIntroduceDefaultLiteralInPatternSwitchCase()
        {
            var source =
@"
class C
{
    void M()
    {
        switch (true)
        {
            case (bool)default when true:
                break;
        }
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp7_1,
            }.RunAsync();
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotIntroduceDefaultLiteralInPatternSwitchCase_CastInsideParentheses()
        {
            var source =
@"
class C
{
    void M()
    {
        switch (true)
        {
            case ((bool)default) when true:
                break;
        }
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp7_1,
            }.RunAsync();
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotIntroduceDefaultLiteralInPatternSwitchCase_DefaultInsideParentheses()
        {
            var source =
@"
class C
{
    void M()
    {
        switch (true)
        {
            case (bool)(default) when true:
                break;
        }
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp7_1,
            }.RunAsync();
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotIntroduceDefaultLiteralInPatternSwitchCase_RemoveDoubleCast()
        {
            var source =
@"
class C
{
    void M()
    {
        switch (true)
        {
            case [|(bool)|][|(bool)|]default when true:
                break;
        }
    }
}";
            var fixedSource =
@"
class C
{
    void M()
    {
        switch (true)
        {
            case (bool)default when true:
                break;
        }
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = fixedSource,
                LanguageVersion = LanguageVersion.CSharp7_1,
            }.RunAsync();
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotIntroduceDefaultLiteralInPatternSwitchCase_RemoveInsideWhenClause()
        {
            var source =
@"
class C
{
    void M()
    {
        switch (true)
        {
            case (bool)default when [|(bool)|]default:
                break;
        }
    }
}";
            var fixedSource =
@"
class C
{
    void M()
    {
        switch (true)
        {
            case (bool)default when default:
                break;
        }
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = fixedSource,
                LanguageVersion = LanguageVersion.CSharp7_1,
            }.RunAsync();
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotIntroduceDefaultLiteralInPatternIs()
        {
            var source =
@"
class C
{
    void M()
    {
        if (true is (bool)default);
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp7_1,
            }.RunAsync();
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotIntroduceDefaultLiteralInPatternIs_CastInsideParentheses()
        {
            var source =
@"
class C
{
    void M()
    {
        if (true is ((bool)default));
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp7_1,
            }.RunAsync();
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotIntroduceDefaultLiteralInPatternIs_DefaultInsideParentheses()
        {
            var source =
@"
class C
{
    void M()
    {
        if (true is (bool)(default));
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp7_1,
            }.RunAsync();
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotIntroduceDefaultLiteralInPatternIs_RemoveDoubleCast()
        {
            var source =
@"
class C
{
    void M()
    {
        if (true is [|(bool)|][|(bool)|]default);
    }
}";
            var fixedSource =
@"
class C
{
    void M()
    {
        if (true is (bool)default) ;
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = fixedSource,
                LanguageVersion = LanguageVersion.CSharp7_1,
            }.RunAsync();
        }

        [WorkItem(27239, "https://github.com/dotnet/roslyn/issues/27239")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotOfferToRemoveCastWhereNoConversionExists()
        {
            var source =
                @"
using System;

class C
{
    void M()
    {
        object o = null;
        TypedReference r2 = {|CS0030:(TypedReference)o|};
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(28412, "https://github.com/dotnet/roslyn/issues/28412")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotOfferToRemoveCastWhenAccessingHiddenProperty()
        {
            var source = @"
using System.Collections.Generic;
class Fruit
{
    public IDictionary<string, object> Properties { get; set; }
}
class Apple : Fruit
{
    public new IDictionary<string, object> Properties { get; }
}
class Tester
{
    public void Test()
    {
        var a = new Apple();
        ((Fruit)a).Properties[""Color""] = ""Red"";
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(31963, "https://github.com/dotnet/roslyn/issues/31963")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotOfferToRemoveCastInConstructorWhenItNeeded()
        {
            var source = @"
class IntegerWrapper
{
    public IntegerWrapper(int value)
    {
    }
}
enum Goo
{
    First,
    Second
}
class Tester
{
    public void Test()
    {
        var a = new IntegerWrapper((int)Goo.First);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(31963, "https://github.com/dotnet/roslyn/issues/31963")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotOfferToRemoveCastInBaseConstructorInitializerWhenItNeeded()
        {
            var source =
@"
class B
{
    B(int a)
    {
    }
}
class C : B
{
    C(double a) : base((int)a)
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                // /0/Test0.cs(10,19): error CS0122: 'B.B(int)' is inaccessible due to its protection level
                DiagnosticResult.CompilerError("CS0122").WithSpan(10, 19, 10, 23).WithArguments("B.B(int)"),
                source);
        }

        [WorkItem(31963, "https://github.com/dotnet/roslyn/issues/31963")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotOfferToRemoveCastInConstructorInitializerWhenItNeeded()
        {
            var source =
@"
class B
{
    B(int a)
    {
    }

    B(double a) : this((int)a)
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(10220, "https://github.com/dotnet/roslyn/issues/10220")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveObjectCastInParamsCall()
        {
            var source =
@"
using System;
using System.Diagnostics;

class Program
{
    static void Main(string[] args)
    {
        object[] arr = { 1, 2, 3 };
        testParams((object)arr);
    }

    static void testParams(params object[] ps)
    {
        Console.WriteLine(ps.Length);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(22804, "https://github.com/dotnet/roslyn/issues/22804")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastFromNullableToUnderlyingType()
        {
            var source =
            @"
using System.Text;

class C
{
    private void M()
    {
        StringBuilder numbers = new StringBuilder();
        int?[] position = new int?[2];
        numbers[(int)position[1]] = 'x';
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(41433, "https://github.com/dotnet/roslyn/issues/41433")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastFromIntPtrToPointer()
        {
            var source =
            @"
using System;

class C
{
    unsafe int Test(IntPtr safePointer)
    {
        return ((int*)safePointer)[0];
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(38599, "https://github.com/dotnet/roslyn/issues/38599")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastFromIntPtrToPointerInReturn()
        {
            var source =
            @"
using System;

class Program
{
    public static unsafe int Read(IntPtr pointer, int offset)
    {
        return ((int*)pointer)[offset];
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(32491, "https://github.com/dotnet/roslyn/issues/32491")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastFromIntPtrToPointerWithTypeParameter()
        {
            var source =
            @"
using System;

struct Block<T>
    where T : unmanaged
{
    IntPtr m_ptr;
    unsafe ref T GetRef( int index )
    {
        return ref ((T*)m_ptr)[index];
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(25021, "https://github.com/dotnet/roslyn/issues/25021")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastFromIntPtrToPointerWithAddressAndCast()
        {
            var source =
            @"
using System;

class C
{
    private unsafe void goo()
    {
        var address = IntPtr.Zero;
        var bar = (int*)&((long*)address)[10];
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(38347, "https://github.com/dotnet/roslyn/issues/38347")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestArgToLocalFunction1()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
class Program
{
    public static void M()
    {
        for (int i = 0; i < 1; i++)
        {
            long a = 0, b = 0;

            SameScope([|(decimal)|]a + [|(decimal)|]b);

            static void SameScope(decimal sum) { }
        }
    }
}",
@"
class Program
{
    public static void M()
    {
        for (int i = 0; i < 1; i++)
        {
            long a = 0, b = 0;

            SameScope(a + (decimal)b);

            static void SameScope(decimal sum) { }
        }
    }
}");
        }

        [WorkItem(38347, "https://github.com/dotnet/roslyn/issues/38347")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestArgToLocalFunction2()
        {
            var source =
@"
class Program
{
    public static void M()
    {
        for (int i = 0; i < 1; i++)
        {
            long a = 0, b = 0;

            SameScope([|(decimal)|]a + [|(decimal)|]b);

            static void SameScope(decimal sum) { }
        }
    }
}";
            var fixedSource =
@"
class Program
{
    public static void M()
    {
        for (int i = 0; i < 1; i++)
        {
            long a = 0, b = 0;

            SameScope((decimal)a + b);

            static void SameScope(decimal sum) { }
        }
    }
}";
            var batchFixedSource =
@"
class Program
{
    public static void M()
    {
        for (int i = 0; i < 1; i++)
        {
            long a = 0, b = 0;

            SameScope(a + (decimal)b);

            static void SameScope(decimal sum) { }
        }
    }
}";

            await new VerifyCS.Test
            {
                TestCode = source,
                FixedCode = fixedSource,
                BatchFixedCode = batchFixedSource,
                CodeFixTestBehaviors = CodeFixTestBehaviors.FixOne,
                DiagnosticSelector = diagnostics => diagnostics[1],
            }.RunAsync();
        }

        [WorkItem(36631, "https://github.com/dotnet/roslyn/issues/36631")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestFormattableString1()
        {
            var source =
            @"
using System;

class C
{
    private void goo()
    {
        object x = (IFormattable)$"""";
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(36631, "https://github.com/dotnet/roslyn/issues/36631")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestFormattableString2()
        {
            var source =
            @"
using System;

class C
{
    private void goo()
    {
        object x = (FormattableString)$"""";
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(36631, "https://github.com/dotnet/roslyn/issues/36631")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestFormattableString3()
        {
            var source =
            @"
using System;

class C
{
    private void goo()
    {
        bar((FormattableString)$"""");
    }

    private void bar(string s) { }
    private void bar(FormattableString s) { }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(36631, "https://github.com/dotnet/roslyn/issues/36631")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestFormattableString4()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

class C
{
    private void goo()
    {
        bar([|(FormattableString)|]$"""");
    }

    private void bar(FormattableString s) { }
}",
@"
using System;

class C
{
    private void goo()
    {
        bar($"""");
    }

    private void bar(FormattableString s) { }
}");
        }

        [WorkItem(36631, "https://github.com/dotnet/roslyn/issues/36631")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestFormattableString5()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

class C
{
    private void goo()
    {
        object o = [|(string)|]$"""";
    }
}",
@"
using System;

class C
{
    private void goo()
    {
        object o = $"""";
    }
}");
        }

        [WorkItem(36631, "https://github.com/dotnet/roslyn/issues/36631")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestFormattableString6()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

class C
{
    private void goo()
    {
        bar([|(IFormattable)|]$"""");
    }

    private void bar(IFormattable s) { }
}",
@"
using System;

class C
{
    private void goo()
    {
        bar($"""");
    }

    private void bar(IFormattable s) { }
}");
        }

        [WorkItem(36631, "https://github.com/dotnet/roslyn/issues/36631")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestFormattableString7()
        {
            var source =
            @"
using System;

class C
{
    private void goo()
    {
        object x = (IFormattable)$@"""";
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(34326, "https://github.com/dotnet/roslyn/issues/34326")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestMissingOnInterfaceCallOnNonSealedClass()
        {
            var source =
@"
using System;

public class DbContext : IDisposable
{
    public void Dispose()
    {
        Console.WriteLine(""Base called"");
    }
}

public class MyContext : DbContext, IDisposable
{
    void IDisposable.Dispose()
    {
        Console.WriteLine(""Derived called"");
    }
}

class C
{
    private readonly DbContext _dbContext = new MyContext();

    static void Main()
    {
        ((IDisposable)_dbContext).Dispose();
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                // /0/Test0.cs(26,23): error CS0120: An object reference is required for the non-static field, method, or property 'C._dbContext'
                DiagnosticResult.CompilerError("CS0120").WithSpan(26, 23, 26, 33).WithArguments("C._dbContext"),
                source);
        }

        [WorkItem(34326, "https://github.com/dotnet/roslyn/issues/34326")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestMissingOnInterfaceCallOnNonReadOnlyStruct()
        {
            var source =
@"
using System;

public struct DbContext : IDisposable
{
    public int DisposeCount;
    public void Dispose()
    {
        DisposeCount++'
    }
}

class C
{
    private DbContext _dbContext = new MyContext();

    static void Main()
    {
        ((IDisposable)_dbContext).Dispose();
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                new[]
                {
                    // /0/Test0.cs(9,23): error CS1010: Newline in constant
                    DiagnosticResult.CompilerError("CS1010").WithSpan(9, 23, 9, 23),
                    // /0/Test0.cs(9,23): error CS1011: Empty character literal
                    DiagnosticResult.CompilerError("CS1011").WithSpan(9, 23, 9, 23),
                    // /0/Test0.cs(9,23): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(9, 23, 9, 24),
                    // /0/Test0.cs(9,24): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(9, 24, 9, 24),
                    // /0/Test0.cs(15,40): error CS0246: The type or namespace name 'MyContext' could not be found (are you missing a using directive or an assembly reference?)
                    DiagnosticResult.CompilerError("CS0246").WithSpan(15, 40, 15, 49).WithArguments("MyContext"),
                    // /0/Test0.cs(19,23): error CS0120: An object reference is required for the non-static field, method, or property 'C._dbContext'
                    DiagnosticResult.CompilerError("CS0120").WithSpan(19, 23, 19, 33).WithArguments("C._dbContext"),
                },
                source);
        }

        [WorkItem(34326, "https://github.com/dotnet/roslyn/issues/34326")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestMissingOnInterfaceCallOnReadOnlyStruct()
        {
            // We technically could support this.  But we choose not to for simplicity. While semantics could be
            // preserved, the semantics around interfaces are subtle and we don't want to make a change that might
            // negatively impact the user if they make other code changes.
            var source =
@"
using System;

public struct DbContext : IDisposable
{
    public int DisposeCount;
    public void Dispose()
    {
        DisposeCount++'
    }
}

class C
{
    private readonly DbContext _dbContext = new MyContext();

    static void Main()
    {
        ((IDisposable)_dbContext).Dispose();
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                new[]
                {
                    // /0/Test0.cs(9,23): error CS1010: Newline in constant
                    DiagnosticResult.CompilerError("CS1010").WithSpan(9, 23, 9, 23),
                    // /0/Test0.cs(9,23): error CS1011: Empty character literal
                    DiagnosticResult.CompilerError("CS1011").WithSpan(9, 23, 9, 23),
                    // /0/Test0.cs(9,23): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(9, 23, 9, 24),
                    // /0/Test0.cs(9,24): error CS1002: ; expected
                    DiagnosticResult.CompilerError("CS1002").WithSpan(9, 24, 9, 24),
                    // /0/Test0.cs(15,49): error CS0246: The type or namespace name 'MyContext' could not be found (are you missing a using directive or an assembly reference?)
                    DiagnosticResult.CompilerError("CS0246").WithSpan(15, 49, 15, 58).WithArguments("MyContext"),
                    // /0/Test0.cs(19,23): error CS0120: An object reference is required for the non-static field, method, or property 'C._dbContext'
                    DiagnosticResult.CompilerError("CS0120").WithSpan(19, 23, 19, 33).WithArguments("C._dbContext"),
                },
                source);
        }

        [WorkItem(34326, "https://github.com/dotnet/roslyn/issues/34326")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestMissingOnInterfaceCallOnSealedClass()
        {
            // While we could offer this, we choose not to because things might change in the future in subtle ways. For
            // example, if the user makes the type unsealed and later adds a subclass that reimplements the interface
            // this will break.

            var source =
@"
using System;

public sealed class DbContext : IDisposable
{
    public void Dispose()
    {
        Console.WriteLine(""Base called"");
    }
}

class C
{
    private readonly DbContext _dbContext = new MyContext();

    static void Main()
    {
        ((IDisposable)_dbContext).Dispose();
    }
}";

            await VerifyCS.VerifyCodeFixAsync(
                source,
                new[]
                {
                    // /0/Test0.cs(14,49): error CS0246: The type or namespace name 'MyContext' could not be found (are you missing a using directive or an assembly reference?)
                    DiagnosticResult.CompilerError("CS0246").WithSpan(14, 49, 14, 58).WithArguments("MyContext"),
                    // /0/Test0.cs(18,23): error CS0120: An object reference is required for the non-static field, method, or property 'C._dbContext'
                    DiagnosticResult.CompilerError("CS0120").WithSpan(18, 23, 18, 33).WithArguments("C._dbContext"),
                },
                source);
        }

        [WorkItem(29726, "https://github.com/dotnet/roslyn/issues/29726")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestDefaultLiteralWithNullableCastInCoalesce()
        {
            var source =
@"
using System;

public class C
{
    public void Goo()
    {
        int x = (int?)(int)default ?? 42;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(6309, "https://github.com/dotnet/roslyn/issues/6309")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestFPIdentityThatMustRemain1()
        {
            var source =
@"
using System;

public class C
{
    float X() => 2 / (float)X();
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(34873, "https://github.com/dotnet/roslyn/issues/34873")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestFPIdentityThatMustRemain2()
        {
            var source =
@"
using System;

public class C
{
    void M()
    {
        float f1 = 0.00000000002f;
        float f2 = 1 / f1;
        double d = (float)f2;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(34873, "https://github.com/dotnet/roslyn/issues/34873")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestFPIdentityThatMustRemain3()
        {
            var source =
@"
using System;

public class C
{
    void M()
    {
        float f1 = 0.00000000002f;
        float f2 = 1 / f1;
        float f3 = (float)f2;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(34873, "https://github.com/dotnet/roslyn/issues/34873")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestCanRemoveFPIdentityOnFieldRead()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

public class C
{
    float f;

    void M()
    {
        var v = [|(float)|]f;
    }
}",
@"
using System;

public class C
{
    float f;

    void M()
    {
        var v = f;
    }
}");
        }

        [WorkItem(34873, "https://github.com/dotnet/roslyn/issues/34873")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestCanRemoveFPIdentityOnFieldWrite()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

public class C
{
    float f;

    void M(float f1)
    {
        f = [|(float)|]f1;
    }
}",
@"
using System;

public class C
{
    float f;

    void M(float f1)
    {
        f = f1;
    }
}");
        }

        [WorkItem(34873, "https://github.com/dotnet/roslyn/issues/34873")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestCanRemoveFPIdentityInFieldInitializer()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

public class C
{
    static float f1;
    static float f2 = [|(float)|]f1;
}",
@"
using System;

public class C
{
    static float f1;
    static float f2 = f1;
}");
        }

        [WorkItem(34873, "https://github.com/dotnet/roslyn/issues/34873")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestCanRemoveFPIdentityOnArrayRead()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

public class C
{
    float[] f;

    void M()
    {
        var v = [|(float)|]f[0];
    }
}",
@"
using System;

public class C
{
    float[] f;

    void M()
    {
        var v = f[0];
    }
}");
        }

        [WorkItem(34873, "https://github.com/dotnet/roslyn/issues/34873")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestCanRemoveFPIdentityOnArrayWrite()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

public class C
{
    float[] f;

    void M(float f2)
    {
        f[0] = [|(float)|]f2;
    }
}",
@"
using System;

public class C
{
    float[] f;

    void M(float f2)
    {
        f[0] = f2;
    }
}");
        }

        [WorkItem(34873, "https://github.com/dotnet/roslyn/issues/34873")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestCanRemoveFPIdentityOnArrayInitializer1()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

public class C
{
    void M(float f2)
    {
        float[] f = { [|(float)|]f2 };
    }
}",
@"
using System;

public class C
{
    void M(float f2)
    {
        float[] f = { f2 };
    }
}");
        }

        [WorkItem(34873, "https://github.com/dotnet/roslyn/issues/34873")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestCanRemoveFPIdentityOnArrayInitializer2()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

public class C
{
    void M(float f2)
    {
        float[] f = new float[] { [|(float)|]f2 };
    }
}",
@"
using System;

public class C
{
    void M(float f2)
    {
        float[] f = new float[] { f2 };
    }
}");
        }

        [WorkItem(34873, "https://github.com/dotnet/roslyn/issues/34873")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestCanRemoveFPIdentityOnImplicitArrayInitializer()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

public class C
{
    void M(float f2)
    {
        float[] f = new[] { [|(float)|]f2 };
    }
}",
@"
using System;

public class C
{
    void M(float f2)
    {
        float[] f = new[] { f2 };
    }
}");
        }

        [WorkItem(37953, "https://github.com/dotnet/roslyn/issues/37953")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestCanRemoveFromUnnecessarySwitchExpressionCast1()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
using System;

class Program
{
    public static void Main() { }

    public static string GetValue(DayOfWeek value)
        => [|(DayOfWeek)|]value switch
        {
            DayOfWeek.Monday => ""Monday"",
            _ => ""Other"",
        };
}",
@"
using System;

class Program
{
    public static void Main() { }

    public static string GetValue(DayOfWeek value)
        => value switch
        {
            DayOfWeek.Monday => ""Monday"",
            _ => ""Other"",
        };
}");
        }

        [WorkItem(37953, "https://github.com/dotnet/roslyn/issues/37953")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestLeaveNecessarySwitchExpressionCast1()
        {
            var source =
@"
using System;

class Program
{
    public static void Main() { }

    public static string GetValue(int value)
        => (DayOfWeek)value switch
        {
            DayOfWeek.Monday => ""Monday"",
            _ => ""Other"",
        };
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrAssignment1()
        {
            var source =
@"
using System;

class C
{
    private long Repro()
    {
        var random = new Random();
        long result = random.Next();
        result <<= 32;
        result |= (long)random.Next();
        return result;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrBinary1()
        {
            var source =
@"
using System;

class C
{
    private long Repro()
    {
        var random = new Random();
        long result = random.Next();
        result <<= 32;
        var v = result | (long)random.Next();
        return result;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrBinary2()
        {
            var source =
@"
using System;

class C
{
    private long Repro()
    {
        var random = new Random();
        long result = random.Next();
        result <<= 32;
        var v = (long)random.Next() | result;
        return result;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithAndAssignment1()
        {

            await VerifyCS.VerifyCodeFixAsync(@"
using System;

class C
{
    private long Repro()
    {
        var random = new Random();
        long result = random.Next();
        result <<= 32;
        result &= [|(long)|]random.Next();
        return result;
    }
}",
@"
using System;

class C
{
    private long Repro()
    {
        var random = new Random();
        long result = random.Next();
        result <<= 32;
        result &= random.Next();
        return result;
    }
}");
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithAndBinary1()
        {

            await VerifyCS.VerifyCodeFixAsync(@"
using System;

class C
{
    private long Repro()
    {
        var random = new Random();
        long result = random.Next();
        result <<= 32;
        var x = result & [|(long)|]random.Next();
        return result;
    }
}",
@"
using System;

class C
{
    private long Repro()
    {
        var random = new Random();
        long result = random.Next();
        result <<= 32;
        var x = result & random.Next();
        return result;
    }
}");
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithAndBinary2()
        {

            await VerifyCS.VerifyCodeFixAsync(@"
using System;

class C
{
    private long Repro()
    {
        var random = new Random();
        long result = random.Next();
        result <<= 32;
        var x = [|(long)|]random.Next() & result;
        return result;
    }
}",
@"
using System;

class C
{
    private long Repro()
    {
        var random = new Random();
        long result = random.Next();
        result <<= 32;
        var x = random.Next() & result;
        return result;
    }
}");
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCase1()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int i32_hi = 1;
        int i32_lo = 1;
        ulong u64 = 1;
        sbyte i08 = 1;
        short i16 = -1;

        object v1 = (((long)i32_hi) << 32) | (long)i32_lo;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCase2()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int i32_hi = 1;
        int i32_lo = 1;
        ulong u64 = 1;
        sbyte i08 = 1;
        short i16 = -1;

        object v2 = (ulong)i32_hi | (ulong)u64;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCase3()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int i32_hi = 1;
        int i32_lo = 1;
        ulong u64 = 1;
        sbyte i08 = 1;
        short i16 = -1;

        object v3 = (ulong)i32_hi | (ulong)i32_lo;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCase4()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
public class sign
{
    public static void Main()
    {
        int i32_hi = 1;
        int i32_lo = 1;
        ulong u64 = 1;
        sbyte i08 = 1;
        short i16 = -1;

        object v4 = (ulong)[|(uint)|](ushort)i08 | (ulong)i32_lo;
    }
}",
@"
public class sign
{
    public static void Main()
    {
        int i32_hi = 1;
        int i32_lo = 1;
        ulong u64 = 1;
        sbyte i08 = 1;
        short i16 = -1;

        object v4 = (ulong)(ushort)i08 | (ulong)i32_lo;
    }
}");
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCase5()
        {

            await VerifyCS.VerifyCodeFixAsync(@"
public class sign
{
    public static void Main()
    {
        int i32_hi = 1;
        int i32_lo = 1;
        ulong u64 = 1;
        sbyte i08 = 1;
        short i16 = -1;

        object v5 = (int)i08 | [|(int)|]i32_lo;
    }
}",
@"
public class sign
{
    public static void Main()
    {
        int i32_hi = 1;
        int i32_lo = 1;
        ulong u64 = 1;
        sbyte i08 = 1;
        short i16 = -1;

        object v5 = (int)i08 | i32_lo;
    }
}");
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCase6()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int i32_hi = 1;
        int i32_lo = 1;
        ulong u64 = 1;
        sbyte i08 = 1;
        short i16 = -1;

        object v6 = (((ulong)i32_hi) << 32) | (uint) i32_lo;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCase7()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int i32_hi = 1;
        int i32_lo = 1;
        ulong u64 = 1;
        sbyte i08 = 1;
        short i16 = -1;

        object v7 = 0x0000BEEFU | (uint)i16;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCase8()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int i32_hi = 1;
        int i32_lo = 1;
        ulong u64 = 1;
        sbyte i08 = 1;
        short i16 = -1;

        object v8 = 0xFFFFBEEFU | (uint)i16;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCase9()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int i32_hi = 1;
        int i32_lo = 1;
        ulong u64 = 1;
        sbyte i08 = 1;
        short i16 = -1;

        object v9 = 0xDEADBEEFU | (uint)i16;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCaseNullable1()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int? i32_hi = 1;
        int? i32_lo = 1;
        ulong? u64 = 1;
        sbyte? i08 = 1;
        short? i16 = -1;

        object v1 = (((long?)i32_hi) << 32) | (long?)i32_lo;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCaseNullable2()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int? i32_hi = 1;
        int? i32_lo = 1;
        ulong? u64 = 1;
        sbyte? i08 = 1;
        short? i16 = -1;

        object v2 = (ulong?)i32_hi | (ulong?)u64;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCaseNullable3()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int? i32_hi = 1;
        int? i32_lo = 1;
        ulong? u64 = 1;
        sbyte? i08 = 1;
        short? i16 = -1;

        object v3 = (ulong?)i32_hi | (ulong?)i32_lo;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCaseNullable4()
        {
            var source = @"
public class sign
{
    public static void Main()
    {
        int? i32_hi = 1;
        int? i32_lo = 1;
        ulong? u64 = 1;
        sbyte? i08 = 1;
        short? i16 = -1;

        object v4 = (ulong?)(uint?)(ushort?)i08 | (ulong?)i32_lo;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCaseNullable5()
        {

            await VerifyCS.VerifyCodeFixAsync(@"
public class sign
{
    public static void Main()
    {
        int? i32_hi = 1;
        int? i32_lo = 1;
        ulong? u64 = 1;
        sbyte? i08 = 1;
        short? i16 = -1;

        object v5 = (int?)i08 | [|(int?)|]i32_lo;
    }
}",
@"
public class sign
{
    public static void Main()
    {
        int? i32_hi = 1;
        int? i32_lo = 1;
        ulong? u64 = 1;
        sbyte? i08 = 1;
        short? i16 = -1;

        object v5 = (int?)i08 | i32_lo;
    }
}");
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCaseNullable6()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int? i32_hi = 1;
        int? i32_lo = 1;
        ulong? u64 = 1;
        sbyte? i08 = 1;
        short? i16 = -1;

        object v6 = (((ulong?)i32_hi) << 32) | (uint?)i32_lo;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCaseNullable7()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int? i32_hi = 1;
        int? i32_lo = 1;
        ulong? u64 = 1;
        sbyte? i08 = 1;
        short? i16 = -1;

        object v7 = 0x0000BEEFU | (uint?)i16;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCaseNullable8()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int? i32_hi = 1;
        int? i32_lo = 1;
        ulong? u64 = 1;
        sbyte? i08 = 1;
        short? i16 = -1;

        object v8 = 0xFFFFBEEFU | (uint?)i16;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(40414, "https://github.com/dotnet/roslyn/issues/40414")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestSignExtensionWithOrCompilerCaseNullable9()
        {
            var source =
@"
public class sign
{
    public static void Main()
    {
        int? i32_hi = 1;
        int? i32_lo = 1;
        ulong? u64 = 1;
        sbyte? i08 = 1;
        short? i16 = -1;

        object v9 = 0xDEADBEEFU | (uint?)i16;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/20211")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNullCastInSwitch1()
        {
            var source =
@"class Program
{
    static void Main()
    {
        switch ((object)null)
        {
          case bool _:
            break;
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/20211")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNullCastInSwitch2()
        {
            var source =
@"class Program
{
    static void Main()
    {
        switch ((object)(null))
        {
          case bool _:
            break;
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/20211")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNullCastInSwitch3()
        {
            var source =
@"class Program
{
    static void Main()
    {
        switch ((bool?)null)
        {
          case bool _:
            break;
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/20211")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNullCastInSwitch4()
        {
            var source =
@"class Program
{
    static void Main()
    {
        switch ((bool?)(null))
        {
          case bool _:
            break;
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/20211")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNullCastInSwitch5()
        {
            var source =
@"class Program
{
    static void Main()
    {
        switch (((object)null))
        {
          case bool _:
            break;
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/20211")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveDefaultCastInSwitch1()
        {
            var source =
@"class Program
{
    static void Main()
    {
        switch ((object)default)
        {
          case bool _:
            break;
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/20211")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveDefaultCastInSwitch2()
        {
            var source =
@"class Program
{
    static void Main()
    {
        switch ((object)(default))
        {
          case bool _:
            break;
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/20211")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveDefaultCastInSwitch3()
        {
            var source =
@"class Program
{
    static void Main()
    {
        switch ((bool?)default)
        {
          case bool _:
            break;
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/20211")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveDefaultCastInSwitch4()
        {
            var source =
@"class Program
{
    static void Main()
    {
        switch ((bool?)(default))
        {
          case bool _:
            break;
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/20211")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveDoubleNullCastInSwitch1()
        {
            var source =
@"class Program
{
    static void Main()
    {
        switch ([|(object)|][|(string)|]null)
        {
          case var _:
            break;
        }
    }
}";
            var fixedCode =
@"class Program
{
    static void Main()
    {
        switch ((string)null)
        {
          case var _:
            break;
        }
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional1()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? (int?)1 : default;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional2()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? ((int?)1) : default;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional3()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? (int?)1 : (default);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional4()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? (int?)1 : null;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional5()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? ((int?)1) : null;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional6()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? (int?)1 : (null);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional7()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? default : (int?)1;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional8()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? default : ((int?)1);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional9()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? (default) : (int?)1;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional10()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? null : (int?)1;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional11()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? null : ((int?)1);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional12()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? (null) : (int?)1;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional13()
        {
            var source =
@"class C
{
    void M(bool x, int? z)
    {
        var y = x ? (long?)z : null;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNecessaryCastInConditional14()
        {
            var source =
@"class C
{
    void M(bool x, int? z)
    {
        var y = x ? (long?)z : default;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnecessaryCastInConditional1()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? [|(int)|]1 : default;
    }
}";

            var fixedCode =
@"class C
{
    void M(bool x)
    {
        int? y = x ? 1 : default;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnecessaryCastInConditional2()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? [|(int)|]1 : 0;
    }
}";

            var fixedCode =
@"class C
{
    void M(bool x)
    {
        int? y = x ? 1 : 0;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnecessaryCastInConditional3()
        {
            var source =
@"class C
{
    void M(bool x, int? z)
    {
        int? y = x ? [|(int)|]1 : z;
    }
}";

            var fixedCode =
@"class C
{
    void M(bool x, int? z)
    {
        int? y = x ? 1 : z;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnecessaryCastInConditional4()
        {
            var source =
@"class C
{
    void M(bool x, int? z)
    {
        int? y = x ? [|(int?)|]1 : z;
    }
}";

            var fixedCode =
@"class C
{
    void M(bool x, int? z)
    {
        int? y = x ? 1 : z;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnecessaryCastInConditional5()
        {
            var source =
@"class C
{
    void M(bool x)
    {
        int? y = x ? [|(int?)|]1 : 0;
    }
}";
            var fixedCode =
@"class C
{
    void M(bool x)
    {
        int? y = x ? 1 : 0;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnnecessaryCastInConditional6()
        {
            var source =
@"class C
{
    void M(bool x, int? z)
    {
        int? y = x ? [|(int?)|]z : null;
    }
}";
            var fixedCode =
@"class C
{
    void M(bool x, int? z)
    {
        int? y = x ? z : null;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [WorkItem(20211, "https://github.com/dotnet/roslyn/issues/21613")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnnecessaryCastInConditional7()
        {
            var source =
@"class C
{
    void M(bool x, int? z)
    {
        int? y = x ? [|(int?)|]z : default;
    }
}";
            var fixedCode =
@"class C
{
    void M(bool x, int? z)
    {
        int? y = x ? z : default;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [WorkItem(20742, "https://github.com/dotnet/roslyn/issues/20742")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNamedArgToParamsParameter1()
        {
            var source =
@"class Program
{
    public void M()
    {
        object[] takesArgs = null;
        TakesParams(bar: (object)takesArgs, goo: true);
    }

    private void TakesParams(bool goo, params object[] bar)
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(20742, "https://github.com/dotnet/roslyn/issues/20742")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoRemoveNamedArgToParamsParameter1()
        {
            var source =
@"class Program
{
    public void M()
    {
        object[] takesArgs = null;
        TakesParams(bar: [|(object[])|]takesArgs, goo: true);
    }

    private void TakesParams(bool goo, params object[] bar)
    {
    }
}";
            var fixedCode =
@"class Program
{
    public void M()
    {
        object[] takesArgs = null;
        TakesParams(bar: takesArgs, goo: true);
    }

    private void TakesParams(bool goo, params object[] bar)
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [WorkItem(20742, "https://github.com/dotnet/roslyn/issues/20742")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoRemoveNamedArgToParamsParameter2()
        {
            var source =
@"class Program
{
    public void M()
    {
        string[] takesArgs = null;
        TakesParams(bar: [|(object[])|]takesArgs, goo: true);
    }

    private void TakesParams(bool goo, params object[] bar)
    {
    }
}";
            var fixedCode =
@"class Program
{
    public void M()
    {
        string[] takesArgs = null;
        TakesParams(bar: takesArgs, goo: true);
    }

    private void TakesParams(bool goo, params object[] bar)
    {
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task ObjectCastInInterpolation1()
        {
            var source =
@"class Program
{
    public void M(int x, int z)
    {
        var v = $""x {[|(object)|]1} z"";
    }
}";
            var fixedCode =
@"class Program
{
    public void M(int x, int z)
    {
        var v = $""x {1} z"";
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task ObjectCastInInterpolation2()
        {
            var source =
@"class Program
{
    public void M(int x, int z)
    {
        var v = $""x {([|(object)|]1)} z"";
    }
}";
            var fixedCode =
@"class Program
{
    public void M(int x, int z)
    {
        var v = $""x {1} z"";
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestIdentityDoubleCast()
        {
            var source =
@"class Program
{
    public void M(object x)
    {
        var v = [|(int)|](int)x;
    }
}";
            var fixedCode =
@"class Program
{
    public void M(object x)
    {
        var v = (int)x;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestUnintendedReferenceComparison1()
        {
            var source =
@"using System;

public class Symbol
{
    public static bool operator ==(Symbol a, Symbol b) => false;
    public static bool operator !=(Symbol a, Symbol b) => false;
}

public class MethodSymbol : Symbol
{
}

class Program
{
    void Main()
    {
        Object a1 = null;
        MethodSymbol a2 = new MethodSymbol();

        Console.WriteLine(a1 == (object)a2);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestUnintendedReferenceComparison2()
        {
            var source =
@"using System;

public class Symbol
{
    public static bool operator ==(Symbol a, Symbol b) => false;
    public static bool operator !=(Symbol a, Symbol b) => false;
}

public class MethodSymbol : Symbol
{
}

class Program
{
    void Main()
    {
        Object a1 = null;
        MethodSymbol a2 = new MethodSymbol();

        Console.WriteLine((object)a1 == a2);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestUnintendedReferenceComparison3()
        {
            var source =
@"using System;

public class Symbol
{
    public static bool operator ==(Symbol a, Symbol b) => false;
    public static bool operator !=(Symbol a, Symbol b) => false;
}

public class MethodSymbol : Symbol
{
}

class Program
{
    void Main()
    {
        Object a1 = null;
        MethodSymbol a2 = new MethodSymbol();

        Console.WriteLine(a1 != (object)a2);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestUnintendedReferenceComparison4()
        {
            var source =
@"using System;

public class Symbol
{
    public static bool operator ==(Symbol a, Symbol b) => false;
    public static bool operator !=(Symbol a, Symbol b) => false;
}

public class MethodSymbol : Symbol
{
}

class Program
{
    void Main()
    {
        Object a1 = null;
        MethodSymbol a2 = new MethodSymbol();

        Console.WriteLine((object)a1 != a2);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestUnintendedReferenceComparison5()
        {
            var source =
@"using System;

public class Symbol
{
    public static bool operator ==(Symbol a, Symbol b) => false;
    public static bool operator !=(Symbol a, Symbol b) => false;
}

public class MethodSymbol : Symbol
{
}

class Program
{
    void Main()
    {
        Object a1 = null;
        MethodSymbol a2 = new MethodSymbol();

        Console.WriteLine(a2 == (object)a1);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestUnintendedReferenceComparison6()
        {
            var source =
@"using System;

public class Symbol
{
    public static bool operator ==(Symbol a, Symbol b) => false;
    public static bool operator !=(Symbol a, Symbol b) => false;
}

public class MethodSymbol : Symbol
{
}

class Program
{
    void Main()
    {
        Object a1 = null;
        MethodSymbol a2 = new MethodSymbol();

        Console.WriteLine((object)a2 == a1);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestUnintendedReferenceComparison7()
        {
            var source =
@"using System;

public class Symbol
{
    public static bool operator ==(Symbol a, Symbol b) => false;
    public static bool operator !=(Symbol a, Symbol b) => false;
}

public class MethodSymbol : Symbol
{
}

class Program
{
    void Main()
    {
        Object a1 = null;
        MethodSymbol a2 = new MethodSymbol();

        Console.WriteLine(a2 != (object)a1);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task TestUnintendedReferenceComparison8()
        {
            var source =
@"using System;

public class Symbol
{
    public static bool operator ==(Symbol a, Symbol b) => false;
    public static bool operator !=(Symbol a, Symbol b) => false;
}

public class MethodSymbol : Symbol
{
}

class Program
{
    void Main()
    {
        Object a1 = null;
        MethodSymbol a2 = new MethodSymbol();

        Console.WriteLine((object)a2 != a1);
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(44382, "https://github.com/dotnet/roslyn/issues/44382")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnParameterInitializer1()
        {
            var source =
@"enum E : byte { }
class C { void F() { void f(E e = (E)byte.MaxValue) { } } }";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(44382, "https://github.com/dotnet/roslyn/issues/44382")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveCastOnParameterInitializer2()
        {
            var source =
@"enum E : byte { }
class C { void f(E e = (E)byte.MaxValue) { } }";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(45695, "https://github.com/dotnet/roslyn/issues/45695")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveNonObjectCastInsideInterpolation()
        {
            var source =
@"
class Other
{
    void Goo()
    {
        char c = '4';
        string s = $""{(int)c:X4}"";
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, source);
        }

        [WorkItem(45695, "https://github.com/dotnet/roslyn/issues/45695")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoRemoveObjectCastInsideInterpolation()
        {
            await VerifyCS.VerifyCodeFixAsync(
@"
class Other
{
    void Goo()
    {
        char c = '4';
        string s = $""{[|(object)|]c:X4}"";
    }
}",
@"
class Other
{
    void Goo()
    {
        char c = '4';
        string s = $""{c:X4}"";
    }
}");
        }

        [WorkItem(47800, "https://github.com/dotnet/roslyn/issues/47800")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveNativeIntCastsAsIdentity()
        {
            var source =
@"using System;

public class C {
    public nint N(IntPtr x) => [|(nint)|]x;
}";
            var fixedCode =
@"using System;

public class C {
    public nint N(IntPtr x) => x;
}";

            var test = new VerifyCS.Test()
            {
                TestCode = source,
                FixedCode = fixedCode,
                LanguageVersion = LanguageVersion.CSharp9
            };

            await test.RunAsync();
        }

        [WorkItem(47800, "https://github.com/dotnet/roslyn/issues/47800")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoRemoveNativeIntCasts()
        {
            var source =
@"using System;

public class C {
    public nuint N(IntPtr x) => (nuint)(nint)x;
}";

            var test = new VerifyCS.Test()
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp9
            };

            await test.RunAsync();
        }

        [WorkItem(47800, "https://github.com/dotnet/roslyn/issues/47800")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveNativeUIntCastsAsIdentity()
        {
            var source =
@"using System;

public class C {
    public nuint N(UIntPtr x) => [|(nuint)|]x;
}";
            var fixedCode =
@"using System;

public class C {
    public nuint N(UIntPtr x) => x;
}";

            var test = new VerifyCS.Test()
            {
                TestCode = source,
                FixedCode = fixedCode,
                LanguageVersion = LanguageVersion.CSharp9
            };

            await test.RunAsync();
        }

        [WorkItem(51123, "https://github.com/dotnet/roslyn/issues/51123")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoRemoveNativeIntCastsToInt()
        {
            var source =
@"using System;

public class C {
    public int N(IntPtr x) => (int)(nint)x;
}";

            var test = new VerifyCS.Test()
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp9
            };

            await test.RunAsync();
        }

        [WorkItem(47800, "https://github.com/dotnet/roslyn/issues/47800")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoRemoveNativeUIntCasts()
        {
            var source =
@"using System;

public class C {
    public nint N(UIntPtr x) => (nint)(nuint)x;
}";

            var test = new VerifyCS.Test()
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp9
            };

            await test.RunAsync();
        }

        [WorkItem(47800, "https://github.com/dotnet/roslyn/issues/47800")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveIntPtrCastsAsIdentity()
        {
            var source =
@"
using System;

class C
{
    public void M(IntPtr x)
    {
        var v = [|(IntPtr)|]x;
    }
}";
            var fixedCode =
@"
using System;

class C
{
    public void M(IntPtr x)
    {
        var v = x;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [WorkItem(47800, "https://github.com/dotnet/roslyn/issues/47800")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUIntPtrCastsAsIdentity()
        {
            var source =
@"
using System;

class C
{
    public void M(UIntPtr x)
    {
        var v = [|(UIntPtr)|]x;
    }
}";
            var fixedCode =
@"
using System;

class C
{
    public void M(UIntPtr x)
    {
        var v = x;
    }
}";

            await VerifyCS.VerifyCodeFixAsync(source, fixedCode);
        }

        [WorkItem(49140, "https://github.com/dotnet/roslyn/issues/49140")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveBitwiseNotOfUnsignedExtendedValue1()
        {
            var source =
@"
class C
{
    public static ulong P(ulong a, uint b)
    {
        return a & ~(ulong)b;
    }
}";

            var test = new VerifyCS.Test()
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp9
            };

            await test.RunAsync();
        }

        [WorkItem(49140, "https://github.com/dotnet/roslyn/issues/49140")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveBitwiseNotOfUnsignedExtendedValue2()
        {
            var source =
@"
class C
{
    public static nuint N(nuint a, uint b)
    {
        return a & ~(nuint)b;
    }
}";

            var test = new VerifyCS.Test()
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp9
            };

            await test.RunAsync();
        }

        [WorkItem(49140, "https://github.com/dotnet/roslyn/issues/49140")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoNotRemoveBitwiseNotOfUnsignedExtendedValue3()
        {
            var source =
@"
class C
{
    public static ulong N()
    {
        return ~(ulong)uint.MaxValue;
    }
}";

            var test = new VerifyCS.Test()
            {
                TestCode = source,
                FixedCode = source,
                LanguageVersion = LanguageVersion.CSharp9
            };

            await test.RunAsync();
        }

        [WorkItem(49140, "https://github.com/dotnet/roslyn/issues/49140")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoRemoveBitwiseNotOfSignExtendedValue1()
        {

            var test = new VerifyCS.Test()
            {
                TestCode = @"
class C
{
    public static long P(long a, int b)
    {
        return a & ~[|(long)|]b;
    }
}",
                FixedCode = @"
class C
{
    public static long P(long a, int b)
    {
        return a & ~b;
    }
}",
                LanguageVersion = LanguageVersion.CSharp9
            };

            await test.RunAsync();
        }

        [WorkItem(49140, "https://github.com/dotnet/roslyn/issues/49140")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task DoRemoveBitwiseNotOfSignExtendedValue2()
        {

            var test = new VerifyCS.Test()
            {
                TestCode = @"
class C
{
    public static nint N(nint a, int b)
    {
        return a & ~[|(nint)|]b;
    }
}",
                FixedCode = @"
class C
{
    public static nint N(nint a, int b)
    {
        return a & ~b;
    }
}",
                LanguageVersion = LanguageVersion.CSharp9
            };

            await test.RunAsync();
        }

        [WorkItem(50000, "https://github.com/dotnet/roslyn/issues/50000")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task KeepNecessaryCastIfRemovalWouldCreateIllegalConditionalExpression()
        {
            await new VerifyCS.Test
            {
                TestCode = @"
class C
{
    ushort Goo(string s)
        => s is null ? (ushort)1234 : ushort.Parse(s);
}
",
                LanguageVersion = LanguageVersion.CSharp9,
            }.RunAsync();
        }

        [WorkItem(50000, "https://github.com/dotnet/roslyn/issues/50000")]
        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)]
        public async Task RemoveUnnecessaryCastWhenConditionalExpressionIsLegal()
        {
            await new VerifyCS.Test
            {
                TestCode = @"
class C
{
    uint Goo(string s)
        => s is null ? [|(uint)|]1234 : uint.Parse(s);
}",
                FixedCode = @"
class C
{
    uint Goo(string s)
        => s is null ? 1234 : uint.Parse(s);
}",
                LanguageVersion = LanguageVersion.CSharp9,
            }.RunAsync();
        }
    }
}