noUnusedImports

JavaScript (and super languages)

Summary

Rule available since: v1.3.0
Diagnostic Category: lint/correctness/noUnusedImports
This rule is recommended, which means is enabled by default.
This rule has an unsafe fix.
The default severity of this rule is warning.
Sources:
- Same as unused-imports/no-unused-imports

How to configure

1
{
2
  "linter": {
3
    "rules": {
4
      "correctness": {
5
        "noUnusedImports": "error"
6
      }
7
    }
8
  }
9
}

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

1
import A from 'mod';

code-block.js:1:8 lint/correctness/noUnusedImports  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’;
      │ --------------------

1
import * as A from 'mod';

code-block.js:1:13 lint/correctness/noUnusedImports  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’;
      │ -------------------------

1
import { type A, B } from 'mod';
2

3
export { B }

code-block.ts:1:10 lint/correctness/noUnusedImports  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’;
      │          --------

1
// Header comment
2
import /*inner comment */ A from 'mod'; // Associated comment

code-block.ts:2:27 lint/correctness/noUnusedImports  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   │ - //·Header·comment
    2   │ - import·/*inner·comment·*/·A·from·‘mod’;·//·Associated·comment
      1 │ + 
    3 2 │

1
// Another header comment
2
import {
3
    // A's header comment
4
    type A, // A's comment
5
    // B's header comment
6
    B,
7
} from 'mod';
8

9
export { B }

code-block.ts:4:5 lint/correctness/noUnusedImports  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,

Valid

1
import { A, type B } from 'mod';
2

3
function f(arg: B): A {
4
    return new A(arg);
5
}

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

1
import type {} from '@mui/lab/themeAugmentation';