title: TS Error: Type 'string' is not an array type or a string type. How a string is not a string?
body: <p>TS throws strange error:</p>
  
  <blockquote>
    <p>Error:(125, 18) TS2569: Type 'string' is not an array type or a string type. Use compiler option '--downlevelIteration' to allow iterating of iterators.</p>
  </blockquote>
  
  <p>How comes a string is not a string? </p>
  
  <p>I want to see how TS is going to compile spread operator for a string.</p>
  
  <p>My code in browser console. A string is broken up into characters:</p>
  
  <pre class="lang-js prettyprint-override"><code>&gt; s = 'abcdef';
  &gt; r = [...s];
  &lt; (6) ["a", "b", "c", "d", "e", "f"]
  </code></pre>
  
  <p>My code in TS:</p>
  
  <pre class="lang-js prettyprint-override"><code>const s: string = 'abcdef';
  const res = [...s]; // &lt;= Error: Type 'string' is not an array type or a string type
  console.log(res);
  </code></pre>
  
  <p>Why?</p>
  
  <p>TS version:</p>
  
  <pre><code>  "dependencies": {
      "typescript": "^3.5.3"
    }
  </code></pre>
  
  <p>UPD:</p>
  
  <p>@VtoCorleone 
  A screenshot
  <a href="https://i.stack.imgur.com/BIcrl.png" rel="noreferrer"><img src="https://i.stack.imgur.com/BIcrl.png" alt="enter image description here"></a></p>
  
  <p>UPD:</p>
  
  <p>My <code>tsconfig.json</code></p>
  
  <pre><code>{
    "compilerOptions": {
      "target": "es5",
      "lib": [
        "dom",
        "dom.iterable",
        "esnext"
      ],
      "downlevelIteration": false,
      "allowJs": true,
      "skipLibCheck": false,
      "esModuleInterop": true,
      "allowSyntheticDefaultImports": true,
      "alwaysStrict": true,
      "strict": true,
      "forceConsistentCasingInFileNames": true,
      "module": "esnext",
      "moduleResolution": "node",
      "resolveJsonModule": true,
      "isolatedModules": false,
      "noEmit": false,
      "sourceMap": true,
      "baseUrl": "./",
      "jsx": "preserve"
    },
    "compileOnSave": true,
    "files": [
      "sample.ts"
    ],
    "exclude": [
      "node_modules",
      "**/*.spec.ts"
    ]
  }
  
  </code></pre>