title: How to write unit test case for switch case in Angular 6?
body: <p>I am new to write test cases for Angular 6, this is my service code. How to write test cases for switch case. I don't know how write this.</p>
  
  <pre><code>import { Injectable } from '@angular/core';
  import { HttpHeaders } from '@angular/common/http';
  const httpOptions = {  headers: new HttpHeaders({ 'Content-Type': 'application/json' })};
  const CUSTOMERS_URL = "http://localhost:8009/api/customers";
  import * as sample1 from "./schema/schema-sample1.json";
  import * as sample2 from "./schema/schema-sample2.json";
  import * as sample3 from "./schema/schema-sample3.json";
  import * as sample4 from "./schema/schema-sample4.json";
  import * as sample5 from "./schema/schema-sample5.json";
  
  @Injectable({
    providedIn: 'root'
  })
  export class AppService {
  
    constructor() { }
  
     getDynamicRequestDetailsForApp(appName){
      switch(appName) {
        case "dcc": {
           return sample1;
           break;
        }
        case "sbr": {
           return sample2;
           break;
        }
        case "arc": {
           return sample3;
           break;
        }
        case "auth": {
           return sample5;
           break;
        }
        default: {
           return sample5;
           break;
        }
     }
    }
  }
  </code></pre>