non-nullable-type-assertion-style.md

Prefers a non-null assertion over explicit type cast when possible (non-nullable-type-assertion-style)

This rule detects when an as cast is doing the same job as a ! would, and suggests fixing the code to be an !.

Rule Details

Examples of incorrect code for this rule:

const maybe = Math.random() > 0.5 ? '' : undefined;

const definitely = maybe as string;
const alsoDefinitely = <string>maybe;

Examples of correct code for this rule:

const maybe = Math.random() > 0.5 ? '' : undefined;

const definitely = maybe!;
const alsoDefinitely = maybe!;

When Not To Use It

If you don't mind having unnecessarily verbose type casts, you can avoid this rule.