noUnusedImports

Diagnostic Category: lint/correctness/noUnusedImports

JavaScript (and super languages)

Since: v1.3.0

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

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 Safe fix: Remove the unused import.
  
    1 │ import·A·from·‘mod’;
      │ --------------------

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 Safe fix: Remove the unused import.
  
    1 │ import·*·as·A·from·‘mod’;
      │ -------------------------

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

export { B }

code-block.ts:1:15 lint/correctness/noUnusedImports  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ This import is unused.
  
  > 1 │ import { type A, B } from ‘mod’;
      │               ^
    2 │ 
    3 │ export { B }
  
  ℹ Unused imports might be the result of an incomplete refactoring.
  
  ℹ Safe fix: Remove the unused import.
  
    1 │ import·{·type·A,·B·}·from·‘mod’;
      │          --------

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

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

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

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

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

How to configure

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