eslint/no-duplicate-imports Style

🚧 An auto-fix is still under development.

What it does

Disallow duplicate module imports.

Why is this bad?

Using a single import statement per module will make the code clearer because you can see everything being imported from that module on one line.

Examples

Examples of incorrect code for this rule:

In the following example the module import on line 1 is repeated on line 3. These can be combined to make the list of imports more succinct.

import { merge } from "module";
import something from "another-module";
import { find } from "module";

Examples of correct code for this rule:

import { merge, find } from "module";
import something from "another-module";

Options

includeExports

{ "includeExports": boolean }

When true this rule will also look at exports to see if there is both a re-export of a module as in export ... from 'module' and also a standard import statement for the same module. This would count as a rule violation because there are in a sense two statements importing from the same module.

Examples of incorrect when this rule is set to true

import { merge } from "module";

export { find } from "module"; // re-export which is an import and an export.

Examples of correct when this rule is set to true

If re-exporting from an imported module, you should add the imports to the import statement, and export that directly, not use export ... from.

import { merge } from "lodash-es";
export { merge as lodashMerge };

import { merge, find } from "module";

// cannot be merged with the above import
export * as something from "module";

// cannot be written differently
export * from "module";

How to use

To enable this rule in the CLI or using the config file, you can use:

CLI

oxlint --deny no-duplicate-imports

Config (.oxlintrc.json)

{
  "rules": {
    "no-duplicate-imports": "error"
  }
}

References

• Rule Source