Difference in the 'lib' property in tsconfig.json between es6 and es2017? : <p>I've been researching what the possible values of the <code>lib</code> property mean in the <code>compilerOptions</code> found within the <code>tsconfig.json</code> file. I found on the <a href="https://github.com/Microsoft/TypeScript/tree/master/lib" rel="noreferrer">Typescript GitHub</a> page the relevant <code>d.ts</code> files corresponding to those values and apparently by using <code>ES2017</code> the following ES features are included:</p>

<pre><code>/// &lt;reference path="lib.es2016.d.ts" /&gt;
/// &lt;reference path="lib.es2017.object.d.ts" /&gt;
/// &lt;reference path="lib.es2017.sharedmemory.d.ts" /&gt;
/// &lt;reference path="lib.es2017.string.d.ts" /&gt;
/// &lt;reference path="lib.es2015.d.ts" /&gt;
/// &lt;reference path="lib.es2016.array.include.d.ts" /&gt;
/// &lt;reference path="lib.es2015.core.d.ts" /&gt;
/// &lt;reference path="lib.es2015.collection.d.ts" /&gt;
/// &lt;reference path="lib.es2015.generator.d.ts" /&gt;
/// &lt;reference path="lib.es2015.iterable.d.ts" /&gt;
/// &lt;reference path="lib.es2015.promise.d.ts" /&gt;
/// &lt;reference path="lib.es2015.proxy.d.ts" /&gt;
/// &lt;reference path="lib.es2015.reflect.d.ts" /&gt;
/// &lt;reference path="lib.es2015.symbol.d.ts" /&gt;
/// &lt;reference path="lib.es2015.symbol.wellknown.d.ts" /&gt;
/// &lt;reference path="lib.es5.d.ts" /&gt;
</code></pre>

<p>But apparently ES6 is not included and has it's own <a href="https://github.com/Microsoft/TypeScript/blob/master/lib/lib.es6.d.ts" rel="noreferrer">file</a> that doesn't reference anything. My question is, if anybody knows, is it safe to assume that by using <code>es2017</code> I cover all the <code>es6</code> functionality (from a typings perspective) or should that be included separately in the <code>lib</code> option?</p>

<p>For example, like this:</p>

<pre><code>{
  ...
  "compilerOptions": {
    ...
    "lib": ["es2017", "dom"]
  },
  ...
  }
}
</code></pre>

<p>OR this:</p>

<pre><code>{
  ...
  "compilerOptions": {
    ...
    "lib": ["es2017", "es6", "dom"]
  },
  ...
  }
}
</code></pre>
