noEmitOnError Configuration in TypeScript

noEmitOnError is a compiler option in tsconfig.json file. If the value of this property is set to true, TypeScript will not generate output JavaScript file if there is any TypeScript error.

{
  "compilerOptions": {
    //...
    "noEmitOnError": true
  }
}

Here is a TypeScript file that has an error:

const input = document.getElementById("age");
const value = input.value;

Here, TypeScript throws an error in second line because input can have a null value if the element does not exist. That will be an issue when we try to access value of null.

By default when we compile, even though TypeScript shows error in console, it generates output JavaScript with below code:

"use strict";
const input = document.getElementById("age");
const value = input.value;

If we set noEmitOnError to true, the out JavaScript is not generated.