JS.TS.NO.NON.NULL.ASSERTION

Disallows non-null assertions using the '!' postfix operator

Rule Details

Using non-null assertions cancels the benefits of the strict null-checking mode.

Examples of code for this rule:

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Incorrect

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interface Foo {
  bar?: string;
}

const foo: Foo = getFoo();
const includesBaz: boolean = foo.bar!.includes('baz');

Correct

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interface Foo {
  bar?: string;
}

const foo: Foo = getFoo();
const includesBaz: boolean = foo.bar?.includes('baz') ?? false;

Options

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// .eslintrc.json
{
  "rules": {
    "@typescript-eslint/no-non-null-assertion": "warn"
  }
}

This rule is not configurable.

When Not To Use It

If you don't care about strict null-checking, then you will not need this rule.

The content on this page is adapted from the ESLint User Guide. Copyright © OpenJS Foundation and other contributors, www.openjsf.org. All rights reserved. https://eslint.org/docs/rules/