title: Typescript how to ignore 'types' can only be used in a .ts file error
body: <p>I have large project (around 700+ files) written in JavaScript with flow. I want to migrate it to TypeScript. My goal is to keep current files intact and I want to write new functions in TypeScript. My problem is it throws me an error <code>'types' can only be used in a .ts file</code>. Is it possible to suppress this error? I definitely don't want to rewrite every single file in solution.</p>
  
  <p>My IDE is visual studio enterprise 2019</p>
  
  <p>tsconfig</p>
  
  <pre><code>{
  "compilerOptions": {
      "target": "es5",
      "lib": [
          "dom",
          "dom.iterable",
          "esnext"
      ],
      "allowJs": true,
      "checkJs": false,
      "skipLibCheck": true,
      "noEmitOnError": true,
      "esModuleInterop": true,
      "allowSyntheticDefaultImports": true,
      "strict": false,
      "forceConsistentCasingInFileNames": true,
      "module": "esnext",
      "moduleResolution": "node",
      "resolveJsonModule": true,
      "isolatedModules": true,
      "noEmit": true,
      "jsx": "preserve"
  },
  "include": [
      "src"
  ]}
  </code></pre>