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

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
3

4
// Another header comment
5
import {
6
    // A's header comment
7
    type A, // A's comment
8
    // B's header comment
9
    B,
10
} from 'mod';
11

12
export { B }

code-block.js:7:5 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ ‘import { type x ident }’ are a TypeScript only feature. Convert your file to a TypeScript file or remove the syntax.
  
    5 │ import {
    6 │     // A’s header comment
  > 7 │     type A, // A’s comment
      │     ^^^^^^
    8 │     // B’s header comment
    9 │     B,
  
  ℹ TypeScript only syntax

Valid

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

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

How to configure

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