title: Create File object type in TypeScript
body: <p>I have a function that should only accept JS <a href="https://developer.mozilla.org/en-US/docs/Web/API/File" rel="noreferrer">File</a> objects.</p>
  
  <p>How do I create that type in TypeScript?</p>
  
  <p>edit: sharing my <code>tsconfig.json</code></p>
  
  <pre><code>{
  "compilerOptions": {
      "outDir": "./ts-dist/",
      "sourceMap": true,
      "noImplicitAny": true,
      "module": "commonjs",
      "target": "es6",
      "jsx": "react",
      "experimentalDecorators": true,
      "emitDecoratorMetadata": true,
      "lib": [
          "dom",
          "es2017"
      ]
  },
  "include": [
      "./src/**/*", "./test/**/*"
  ],
  "exclude": [
      "node_modules", "dist"
  ]
  }
  </code></pre>