noUnusedImports

import { Tabs, TabItem } from '@astrojs/starlight/components';

<Tabs> <TabItem label="JavaScript (and super languages)" icon="seti:javascript"> ## Summary - Rule available since: `v1.3.0` - Diagnostic Category: [`lint/correctness/noUnusedImports`](/reference/diagnostics#diagnostic-category) - This rule is **recommended**, meaning it is enabled by default. - This rule has an [**unsafe**](/linter/#unsafe-fixes) fix. - The default severity of this rule is [**warning**](/reference/diagnostics#warning). - Sources: - Same as [`unused-imports/no-unused-imports`](https://github.com/sweepline/eslint-plugin-unused-imports/blob/master/docs/rules/no-unused-imports.md)

How to configure

json

{
	"linter": {
		"rules": {
			"correctness": {
				"noUnusedImports": "error"
			}
		}
	}
}

Description

Disallow unused imports.

Unused imports might be the result of an incomplete refactoring. The code fix can remove comments associated with an import. See the last invalid example.

Note that the leading trivia, e.g., comments or newlines preceding the unused imports will also be removed. So that comment directives like @ts-expect-error won't be transferred to a wrong place.

Options

This rule respects the jsxRuntime setting and will make an exception for React globals if it is set to "reactClassic".

Examples

Invalid

import A from 'mod';

<pre class="language-text"><code class="language-text">code-block.js:1:8 <a href="https://biomejs.dev/linter/rules/no-unused-imports">lint/correctness/noUnusedImports</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ This import is unused. > 1 │ import A from 'mod'; │ ^ 2 │ ℹ Unused imports might be the result of an incomplete refactoring. ℹ Unsafe fix: Remove the unused imports. 1 │ import·A·from·'mod'; │ -------------------- </code></pre>

import * as A from 'mod';

<pre class="language-text"><code class="language-text">code-block.js:1:13 <a href="https://biomejs.dev/linter/rules/no-unused-imports">lint/correctness/noUnusedImports</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ This import is unused. > 1 │ import * as A from 'mod'; │ ^ 2 │ ℹ Unused imports might be the result of an incomplete refactoring. ℹ Unsafe fix: Remove the unused imports. 1 │ import·*·as·A·from·'mod'; │ ------------------------- </code></pre>

import { type A, B } from 'mod';

export { B }

<pre class="language-text"><code class="language-text">code-block.ts:1:10 <a href="https://biomejs.dev/linter/rules/no-unused-imports">lint/correctness/noUnusedImports</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Several of these imports are unused. > 1 │ import { type A, B } from 'mod'; │ ^^^^^^ 2 │ 3 │ export { B } ℹ Unused imports might be the result of an incomplete refactoring. ℹ Unsafe fix: Remove the unused imports. 1 │ import·{·type·A,·B·}·from·'mod'; │ -------- </code></pre>

// Header comment
import /*inner comment */ A from 'mod'; // Associated comment

<pre class="language-text"><code class="language-text">code-block.ts:2:27 <a href="https://biomejs.dev/linter/rules/no-unused-imports">lint/correctness/noUnusedImports</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ This import is unused. 1 │ // Header comment > 2 │ import /*inner comment */ A from 'mod'; // Associated comment │ ^ 3 │ ℹ Unused imports might be the result of an incomplete refactoring. ℹ Unsafe fix: Remove the unused imports. 1 1 │ // Header comment 2 │ - import·/*inner·comment·*/·A·from·'mod';·//·Associated·comment 2 │ + export·{}·//·Associated·comment 3 3 │ </code></pre>

// Another header comment
import {
    // A's header comment
    type A, // A's comment
    // B's header comment
    B,
} from 'mod';

export { B }

<pre class="language-text"><code class="language-text">code-block.ts:4:5 <a href="https://biomejs.dev/linter/rules/no-unused-imports">lint/correctness/noUnusedImports</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Several of these imports are unused. 2 │ import { 3 │ // A's header comment > 4 │ type A, // A's comment │ ^^^^^^ 5 │ // B's header comment 6 │ B, ℹ Unused imports might be the result of an incomplete refactoring. ℹ Unsafe fix: Remove the unused imports. 1 1 │ // Another header comment 2 2 │ import { 3 │ - ····//·A's·header·comment 4 │ - ····type·A,·//·A's·comment 5 3 │ // B's header comment 6 4 │ B, </code></pre>

Valid

import { A, type B } from 'mod';

function f(arg: B): A {
    return new A(arg);
}

One notable exception is when the import is intended to be used for type augmentation.

import type {} from '@mui/lab/themeAugmentation';

</TabItem> </Tabs>