#no-duplicate-imports

#Configuration

import { defineConfig, js } from '@rslint/core';

export default defineConfig([
  js.configs.recommended,
  {
    rules: {
      'no-duplicate-imports': 'error',
    },
  },
]);

#Rule Details

Disallow duplicate module imports. Multiple import statements (and optionally export ... from re-exports) referencing the same module can usually be merged into a single statement, which makes dependencies easier to scan and avoids redundant module entries.

Examples of incorrect code for this rule:

import { merge } from "lodash-es";
import { find } from "lodash-es";

import { merge } from "lodash-es";
import _ from "lodash-es";

Examples of correct code for this rule:

import { merge, find } from "lodash-es";

import _, { merge, find } from "lodash-es";

A namespace import together with a named import is allowed because the two forms cannot be merged into a single statement:

import * as bar from "os";
import { baz } from "os";

#Options

This rule accepts an options object with the following properties:

• includeExports (default: false) — when true, also flag export { ... } from, export * from, and export * as ns from re-exports that duplicate (or could be merged with) an earlier import or export of the same module.
• allowSeparateTypeImports (default: false) — when true, a declaration-level import type / export type does NOT collide with a non-type import/export of the same module, so import { foo } from "m" and import type { Bar } from "m" are allowed. Specifier-level type keywords (import { type Foo } from "m") do NOT count for this exemption — they only apply when the entire declaration is type-only.

#includeExports

Examples of incorrect code with { "includeExports": true }:

{ "no-duplicate-imports": ["error", { "includeExports": true }] }

import os from "os";
export { something } from "os";

{ "no-duplicate-imports": ["error", { "includeExports": true }] }

export * from "os";
export * from "os";

Examples of correct code with { "includeExports": true }:

{ "no-duplicate-imports": ["error", { "includeExports": true }] }

import os from "os";
export * from "os";

A import * as plus an export { x } from of the same module is allowed because the two forms cannot be merged into a single statement:

{ "no-duplicate-imports": ["error", { "includeExports": true }] }

import * as os from "os";
export { something } from "os";

#allowSeparateTypeImports

Examples of correct code with { "allowSeparateTypeImports": true }:

{ "no-duplicate-imports": ["error", { "allowSeparateTypeImports": true }] }

import { foo } from "module";
import type { Bar } from "module";

Examples of incorrect code with { "allowSeparateTypeImports": true }:

{ "no-duplicate-imports": ["error", { "allowSeparateTypeImports": true }] }

import { type Foo } from "module";
import { type Bar } from "module";

{ "no-duplicate-imports": ["error", { "allowSeparateTypeImports": true }] }

import type { Merge } from "lodash-es";
import type { Find } from "lodash-es";

#Original Documentation

• ESLint rule: no-duplicate-imports