Why does my React Native app build successfully despite TypeScript compiler error? : <p>I've recently started using TypeScript with Expo. I've done all the linter/formatter integrations like <code>typescript-eslint</code> so I can catch most of the errors during coding. To check if the code compiles, I run <code>npx tsc</code> every once in a while and fix accordingly.</p>

<p>One thing that I haven't fully grasped yet is why my app builds successfully even when there are numerous compile errors. I expect (and prefer) to see a red screen error for every compile error rather than the app build successfully and me find it out later. For example,</p>

<pre><code>function square&lt;T&gt;(x: T): T {
  console.log(x.length); // error TS2339: Property 'length' does not exist on type 'T'.
  return x * x;
}
</code></pre>

<p>is a typical TypeScript error that (I believe?) can be easily checked at compile time. I want it to result in a big red screen error and the build to fail.</p>

<p>I'm quite new to TypeScript so it's possible that I'm missing something very important. What exactly is causing this leniency and is there a way to enforce stricter checks?</p>
