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non-nullable-type-assertion-style

Prefers a non-null assertion over explicit type cast when possible.

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 code for this rule:

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

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

Options

// .eslintrc.json
{
"rules": {
"@typescript-eslint/non-nullable-type-assertion-style": "warn"
}
}

This rule is not configurable.

When Not To Use It

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

Attributes

  • Configs:
    • ✅ Recommended
    • 🔒 Strict
  • 🔧 Fixable
  • 💭 Requires type information