<p dir="auto">With these settings in browserlist build failed:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&gt;= 1%"><pre class="notranslate"><code class="notranslate">&gt;= 1%
</code></pre></div>
<p dir="auto">or</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&gt;= 2.5%"><pre class="notranslate"><code class="notranslate">&gt;= 2.5%
</code></pre></div>
<p dir="auto">but works with</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&gt;= 1.1%"><pre class="notranslate"><code class="notranslate">&gt;= 1.1%
</code></pre></div>
<p dir="auto">or</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&gt;= 2.5%
ie 11"><pre class="notranslate"><code class="notranslate">&gt;= 2.5%
ie 11
</code></pre></div>
<p dir="auto">which both differs only for <code class="notranslate">ie 11</code></p>
<p dir="auto">error:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="ERROR in ./src/containers/Employees/EditEmployeeContainer.js                                                                                                                                                 
Module build failed (from ./node_modules/babel-loader/lib/index.js):                                                                                                                                         
TypeError: C:\Projects\topcase\hrketing\src\Web\WebSPA\src\containers\Employees\EditEmployeeContainer.js: Duplicate declaration &quot;modifiedAlternativeNames&quot; (This is an error on an internal node. Probably an
    at File.buildCodeFrameError (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\core\lib\transformation\file\file.js:250:12)                                                                
    at Scope.checkBlockScopedCollisions (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:419:22)                                                                 
    at Scope.registerBinding (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:579:16)                                                                            
    at Scope.registerDeclaration (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:521:14)                                                                        
    at Object.BlockScoped (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:250:12)                                                                               
    at Object.newFn (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\visitors.js:216:17)                                                                                        
    at NodePath._call (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\path\context.js:55:20)                                                                                   
    at NodePath.call (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\path\context.js:38:14)                                                                                    
    at NodePath.visit (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\path\context.js:92:31)                                                                                   
    at TraversalContext.visitQueue (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\context.js:112:16)                                                                          
 @ ./src/containers/Router.js 28:54-97                                                                                                                                                                       
 @ ./src/containers/App.js 22:0-73 155:24-35 156:27-38 200:54-65 207:42-48                                                                                                                                   
 @ ./src/containers/Root.js 21:36-51                                                                                                                                                                         
 @ ./src/index.js 26:0-37 51:38-42                                                                                                                                                                           
                                                                                                                                                                                                             
ERROR in ./src/containers/Trips/CreateEditTripContainer.js                                                                                                                                                   
Module build failed (from ./node_modules/babel-loader/lib/index.js):                                                                                                                                         
TypeError: C:\Projects\topcase\hrketing\src\Web\WebSPA\src\containers\Trips\CreateEditTripContainer.js: Duplicate declaration &quot;origin&quot; (This is an error on an internal node. Probably an internal error.)   
    at File.buildCodeFrameError (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\core\lib\transformation\file\file.js:250:12)                                                                
    at Scope.checkBlockScopedCollisions (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:419:22)                                                                 
    at Scope.registerBinding (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:579:16)                                                                            
    at Scope.registerDeclaration (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:521:14)                                                                        
    at Object.BlockScoped (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:250:12)                                                                               
    at Object.newFn (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\visitors.js:216:17)                                                                                        
    at NodePath._call (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\path\context.js:55:20)                                                                                   
    at NodePath.call (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\path\context.js:38:14)                                                                                    
    at NodePath.visit (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\path\context.js:92:31)                                                                                   
    at TraversalContext.visitQueue (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\context.js:112:16)                                                                          
 @ ./src/containers/Router.js 25:56-97                                                                                                                                                                       
 @ ./src/containers/App.js 22:0-73 155:24-35 156:27-38 200:54-65 207:42-48                                                                                                                                   
 @ ./src/containers/Root.js 21:36-51                                                                                                                                                                         
 @ ./src/index.js 26:0-37 51:38-42                                                                                                                                                                           "><pre class="notranslate"><code class="notranslate">ERROR in ./src/containers/Employees/EditEmployeeContainer.js                                                                                                                                                 
Module build failed (from ./node_modules/babel-loader/lib/index.js):                                                                                                                                         
TypeError: C:\Projects\topcase\hrketing\src\Web\WebSPA\src\containers\Employees\EditEmployeeContainer.js: Duplicate declaration "modifiedAlternativeNames" (This is an error on an internal node. Probably an
    at File.buildCodeFrameError (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\core\lib\transformation\file\file.js:250:12)                                                                
    at Scope.checkBlockScopedCollisions (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:419:22)                                                                 
    at Scope.registerBinding (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:579:16)                                                                            
    at Scope.registerDeclaration (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:521:14)                                                                        
    at Object.BlockScoped (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:250:12)                                                                               
    at Object.newFn (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\visitors.js:216:17)                                                                                        
    at NodePath._call (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\path\context.js:55:20)                                                                                   
    at NodePath.call (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\path\context.js:38:14)                                                                                    
    at NodePath.visit (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\path\context.js:92:31)                                                                                   
    at TraversalContext.visitQueue (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\context.js:112:16)                                                                          
 @ ./src/containers/Router.js 28:54-97                                                                                                                                                                       
 @ ./src/containers/App.js 22:0-73 155:24-35 156:27-38 200:54-65 207:42-48                                                                                                                                   
 @ ./src/containers/Root.js 21:36-51                                                                                                                                                                         
 @ ./src/index.js 26:0-37 51:38-42                                                                                                                                                                           
                                                                                                                                                                                                             
ERROR in ./src/containers/Trips/CreateEditTripContainer.js                                                                                                                                                   
Module build failed (from ./node_modules/babel-loader/lib/index.js):                                                                                                                                         
TypeError: C:\Projects\topcase\hrketing\src\Web\WebSPA\src\containers\Trips\CreateEditTripContainer.js: Duplicate declaration "origin" (This is an error on an internal node. Probably an internal error.)   
    at File.buildCodeFrameError (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\core\lib\transformation\file\file.js:250:12)                                                                
    at Scope.checkBlockScopedCollisions (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:419:22)                                                                 
    at Scope.registerBinding (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:579:16)                                                                            
    at Scope.registerDeclaration (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:521:14)                                                                        
    at Object.BlockScoped (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\scope\index.js:250:12)                                                                               
    at Object.newFn (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\visitors.js:216:17)                                                                                        
    at NodePath._call (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\path\context.js:55:20)                                                                                   
    at NodePath.call (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\path\context.js:38:14)                                                                                    
    at NodePath.visit (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\path\context.js:92:31)                                                                                   
    at TraversalContext.visitQueue (C:\Projects\topcase\hrketing\src\Web\WebSPA\node_modules\@babel\traverse\lib\context.js:112:16)                                                                          
 @ ./src/containers/Router.js 25:56-97                                                                                                                                                                       
 @ ./src/containers/App.js 22:0-73 155:24-35 156:27-38 200:54-65 207:42-48                                                                                                                                   
 @ ./src/containers/Root.js 21:36-51                                                                                                                                                                         
 @ ./src/index.js 26:0-37 51:38-42                                                                                                                                                                           
</code></pre></div>
<p dir="auto">system:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="λ npx envinfo --preset babel

  System:
    OS: Windows 10 10.0.19041
  Binaries:
    Node: 12.18.4 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.22.5 - C:\Program Files (x86)\Yarn\bin\yarn.CMD
    npm: 6.14.8 - C:\Program Files\nodejs\npm.CMD
  npmPackages:
    @babel/cli: ^7.12.1 =&gt; 7.12.1
    @babel/core: ^7.12.3 =&gt; 7.12.3
    @babel/eslint-parser: ^7.12.1 =&gt; 7.12.1
    @babel/eslint-plugin: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-class-properties: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-decorators: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-do-expressions: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-export-default-from: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-export-namespace-from: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-function-bind: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-function-sent: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-json-strings: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-logical-assignment-operators: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-nullish-coalescing-operator: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-numeric-separator: ^7.12.1 =&gt; 7.12.5
    @babel/plugin-proposal-optional-chaining: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-pipeline-operator: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-throw-expressions: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-syntax-dynamic-import: ^7.8.3 =&gt; 7.8.3
    @babel/plugin-syntax-import-meta: ^7.10.4 =&gt; 7.10.4
    @babel/plugin-transform-flow-strip-types: ^7.12.1 =&gt; 7.12.1
    @babel/preset-env: ^7.12.1 =&gt; 7.12.1
    @babel/preset-flow: ^7.12.1 =&gt; 7.12.1
    @babel/preset-react: ^7.12.1 =&gt; 7.12.5
    @babel/register: ^7.12.1 =&gt; 7.12.1
    babel-jest: ^26.6.1 =&gt; 26.6.3
    babel-loader: ^8.1.0 =&gt; 8.1.0
    babel-plugin-import: ^1.13.1 =&gt; 1.13.1
    babel-plugin-macros: ^2.8.0 =&gt; 2.8.0
    babel-plugin-module-resolver: ^4.0.0 =&gt; 4.0.0
    babel-plugin-react-intl: ^8.2.10 =&gt; 8.2.13
    babel-plugin-styled-components: ^1.11.1 =&gt; 1.11.1
    babel-plugin-transform-react-remove-prop-types: ^0.4.24 =&gt; 0.4.24
    eslint: ^7.12.1 =&gt; 7.12.1
    eslint-import-resolver-babel-module: ^5.2.0 =&gt; 5.2.0
    jest: ^26.6.1 =&gt; 26.6.3
    webpack: ^5.4.0 =&gt; 5.4.0"><pre class="notranslate"><code class="notranslate">λ npx envinfo --preset babel

  System:
    OS: Windows 10 10.0.19041
  Binaries:
    Node: 12.18.4 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.22.5 - C:\Program Files (x86)\Yarn\bin\yarn.CMD
    npm: 6.14.8 - C:\Program Files\nodejs\npm.CMD
  npmPackages:
    @babel/cli: ^7.12.1 =&gt; 7.12.1
    @babel/core: ^7.12.3 =&gt; 7.12.3
    @babel/eslint-parser: ^7.12.1 =&gt; 7.12.1
    @babel/eslint-plugin: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-class-properties: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-decorators: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-do-expressions: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-export-default-from: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-export-namespace-from: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-function-bind: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-function-sent: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-json-strings: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-logical-assignment-operators: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-nullish-coalescing-operator: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-numeric-separator: ^7.12.1 =&gt; 7.12.5
    @babel/plugin-proposal-optional-chaining: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-pipeline-operator: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-proposal-throw-expressions: ^7.12.1 =&gt; 7.12.1
    @babel/plugin-syntax-dynamic-import: ^7.8.3 =&gt; 7.8.3
    @babel/plugin-syntax-import-meta: ^7.10.4 =&gt; 7.10.4
    @babel/plugin-transform-flow-strip-types: ^7.12.1 =&gt; 7.12.1
    @babel/preset-env: ^7.12.1 =&gt; 7.12.1
    @babel/preset-flow: ^7.12.1 =&gt; 7.12.1
    @babel/preset-react: ^7.12.1 =&gt; 7.12.5
    @babel/register: ^7.12.1 =&gt; 7.12.1
    babel-jest: ^26.6.1 =&gt; 26.6.3
    babel-loader: ^8.1.0 =&gt; 8.1.0
    babel-plugin-import: ^1.13.1 =&gt; 1.13.1
    babel-plugin-macros: ^2.8.0 =&gt; 2.8.0
    babel-plugin-module-resolver: ^4.0.0 =&gt; 4.0.0
    babel-plugin-react-intl: ^8.2.10 =&gt; 8.2.13
    babel-plugin-styled-components: ^1.11.1 =&gt; 1.11.1
    babel-plugin-transform-react-remove-prop-types: ^0.4.24 =&gt; 0.4.24
    eslint: ^7.12.1 =&gt; 7.12.1
    eslint-import-resolver-babel-module: ^5.2.0 =&gt; 5.2.0
    jest: ^26.6.1 =&gt; 26.6.3
    webpack: ^5.4.0 =&gt; 5.4.0
</code></pre></div>
<p dir="auto"><strong>I did not check the specs on the scopes, but I am assuming that v8 behavior is correct and that in <code class="notranslate">for (let a of/in b)</code> part <code class="notranslate">b</code> should be outside of the <code class="notranslate">for</code> scope. This is how v8 does things. This is also how babel does things in <code class="notranslate">for of</code> blocks.</strong></p>
<h1 dir="auto"></h1>
<div class="highlight highlight-source-js notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="&quot;use strict&quot;;
var a = [[], [1, 2, 3]];
var i = 1;
for (let i in a[i]) {
    console.log(i);
}"><pre class="notranslate"><span class="pl-s">"use strict"</span><span class="pl-kos">;</span>
<span class="pl-k">var</span> <span class="pl-s1">a</span> <span class="pl-c1">=</span> <span class="pl-kos">[</span><span class="pl-kos">[</span><span class="pl-kos">]</span><span class="pl-kos">,</span> <span class="pl-kos">[</span><span class="pl-c1">1</span><span class="pl-kos">,</span> <span class="pl-c1">2</span><span class="pl-kos">,</span> <span class="pl-c1">3</span><span class="pl-kos">]</span><span class="pl-kos">]</span><span class="pl-kos">;</span>
<span class="pl-k">var</span> <span class="pl-s1">i</span> <span class="pl-c1">=</span> <span class="pl-c1">1</span><span class="pl-kos">;</span>
<span class="pl-k">for</span> <span class="pl-kos">(</span><span class="pl-k">let</span> <span class="pl-s1">i</span> <span class="pl-k">in</span> <span class="pl-s1">a</span><span class="pl-kos">[</span><span class="pl-s1">i</span><span class="pl-kos">]</span><span class="pl-kos">)</span> <span class="pl-kos">{</span>
    <span class="pl-smi">console</span><span class="pl-kos">.</span><span class="pl-en">log</span><span class="pl-kos">(</span><span class="pl-s1">i</span><span class="pl-kos">)</span><span class="pl-kos">;</span>
<span class="pl-kos">}</span></pre></div>
<p dir="auto">is translated to</p>
<div class="highlight highlight-source-js notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="&quot;use strict&quot;;
var a = [[], [1, 2, 3]];
var i = 1;
for (var _i in a[_i]) {
    console.log(_i);
}"><pre class="notranslate"><span class="pl-s">"use strict"</span><span class="pl-kos">;</span>
<span class="pl-k">var</span> <span class="pl-s1">a</span> <span class="pl-c1">=</span> <span class="pl-kos">[</span><span class="pl-kos">[</span><span class="pl-kos">]</span><span class="pl-kos">,</span> <span class="pl-kos">[</span><span class="pl-c1">1</span><span class="pl-kos">,</span> <span class="pl-c1">2</span><span class="pl-kos">,</span> <span class="pl-c1">3</span><span class="pl-kos">]</span><span class="pl-kos">]</span><span class="pl-kos">;</span>
<span class="pl-k">var</span> <span class="pl-s1">i</span> <span class="pl-c1">=</span> <span class="pl-c1">1</span><span class="pl-kos">;</span>
<span class="pl-k">for</span> <span class="pl-kos">(</span><span class="pl-k">var</span> <span class="pl-s1">_i</span> <span class="pl-k">in</span> <span class="pl-s1">a</span><span class="pl-kos">[</span><span class="pl-s1">_i</span><span class="pl-kos">]</span><span class="pl-kos">)</span> <span class="pl-kos">{</span>
    <span class="pl-smi">console</span><span class="pl-kos">.</span><span class="pl-en">log</span><span class="pl-kos">(</span><span class="pl-s1">_i</span><span class="pl-kos">)</span><span class="pl-kos">;</span>
<span class="pl-kos">}</span></pre></div>
<p dir="auto">when it should be translated to</p>
<div class="highlight highlight-source-js notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="&quot;use strict&quot;;
var a = [[], [1, 2, 3]];
var i = 1;
for (var _i in a[i]) {
    console.log(_i);
}"><pre class="notranslate"><span class="pl-s">"use strict"</span><span class="pl-kos">;</span>
<span class="pl-k">var</span> <span class="pl-s1">a</span> <span class="pl-c1">=</span> <span class="pl-kos">[</span><span class="pl-kos">[</span><span class="pl-kos">]</span><span class="pl-kos">,</span> <span class="pl-kos">[</span><span class="pl-c1">1</span><span class="pl-kos">,</span> <span class="pl-c1">2</span><span class="pl-kos">,</span> <span class="pl-c1">3</span><span class="pl-kos">]</span><span class="pl-kos">]</span><span class="pl-kos">;</span>
<span class="pl-k">var</span> <span class="pl-s1">i</span> <span class="pl-c1">=</span> <span class="pl-c1">1</span><span class="pl-kos">;</span>
<span class="pl-k">for</span> <span class="pl-kos">(</span><span class="pl-k">var</span> <span class="pl-s1">_i</span> <span class="pl-k">in</span> <span class="pl-s1">a</span><span class="pl-kos">[</span><span class="pl-s1">i</span><span class="pl-kos">]</span><span class="pl-kos">)</span> <span class="pl-kos">{</span>
    <span class="pl-smi">console</span><span class="pl-kos">.</span><span class="pl-en">log</span><span class="pl-kos">(</span><span class="pl-s1">_i</span><span class="pl-kos">)</span><span class="pl-kos">;</span>
<span class="pl-kos">}</span></pre></div>
<h1 dir="auto"></h1>
<p dir="auto">A similar (or the same) issue:</p>
<div class="highlight highlight-source-js notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="&quot;use strict&quot;;
{
  let i = [1, 2, 3];
}
for (let i in i) {
  console.log(i);
}"><pre class="notranslate"><span class="pl-s">"use strict"</span><span class="pl-kos">;</span>
<span class="pl-kos">{</span>
  <span class="pl-k">let</span> <span class="pl-s1">i</span> <span class="pl-c1">=</span> <span class="pl-kos">[</span><span class="pl-c1">1</span><span class="pl-kos">,</span> <span class="pl-c1">2</span><span class="pl-kos">,</span> <span class="pl-c1">3</span><span class="pl-kos">]</span><span class="pl-kos">;</span>
<span class="pl-kos">}</span>
<span class="pl-k">for</span> <span class="pl-kos">(</span><span class="pl-k">let</span> <span class="pl-s1">i</span> <span class="pl-k">in</span> <span class="pl-s1">i</span><span class="pl-kos">)</span> <span class="pl-kos">{</span>
  <span class="pl-smi">console</span><span class="pl-kos">.</span><span class="pl-en">log</span><span class="pl-kos">(</span><span class="pl-s1">i</span><span class="pl-kos">)</span><span class="pl-kos">;</span>
<span class="pl-kos">}</span></pre></div>
<p dir="auto">should have the same variable renames (not the same code) as in</p>
<div class="highlight highlight-source-js notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="&quot;use strict&quot;;
{
  let i = [1, 2, 3];
}
var i;
for (let i in i) {
  console.log(i);
}"><pre class="notranslate"><span class="pl-s">"use strict"</span><span class="pl-kos">;</span>
<span class="pl-kos">{</span>
  <span class="pl-k">let</span> <span class="pl-s1">i</span> <span class="pl-c1">=</span> <span class="pl-kos">[</span><span class="pl-c1">1</span><span class="pl-kos">,</span> <span class="pl-c1">2</span><span class="pl-kos">,</span> <span class="pl-c1">3</span><span class="pl-kos">]</span><span class="pl-kos">;</span>
<span class="pl-kos">}</span>
<span class="pl-k">var</span> <span class="pl-s1">i</span><span class="pl-kos">;</span>
<span class="pl-k">for</span> <span class="pl-kos">(</span><span class="pl-k">let</span> <span class="pl-s1">i</span> <span class="pl-k">in</span> <span class="pl-s1">i</span><span class="pl-kos">)</span> <span class="pl-kos">{</span>
  <span class="pl-smi">console</span><span class="pl-kos">.</span><span class="pl-en">log</span><span class="pl-kos">(</span><span class="pl-s1">i</span><span class="pl-kos">)</span><span class="pl-kos">;</span>
<span class="pl-kos">}</span></pre></div>
<p dir="auto">but no variables are renamed in the first variant.</p>