import/no-unassigned-import Suspicious

What it does

This rule aims to remove modules with side-effects by reporting when a module is imported but not assigned.

Why is this bad?

With both CommonJS' require and the ES modules' import syntax, it is possible to import a module but not to use its result. This can be done explicitly by not assigning the module to a variable. Doing so can mean either of the following things:

The module is imported but not used
The module has side-effects. Having side-effects, makes it hard to know whether the module is actually used or can be removed. It can also make it harder to test or mock parts of your application.

Examples

Examples of incorrect code for this rule:

import "should";
require("should");

Examples of correct code for this rule:

import _ from "foo";
import _, { foo } from "foo";
import _, { foo as bar } from "foo";
const _ = require("foo");
const { foo } = require("foo");
const { foo: bar } = require("foo");
bar(require("foo"));

Configuration

This rule accepts a configuration object with the following properties:

allow

type: string[]

default: []

A list of glob patterns to allow unassigned imports for specific modules. For example: { "allow": ["**/*.css"] } will allow unassigned imports for any module ending with .css.

How to use

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

Config (.oxlintrc.json)Config (oxlint.config.ts)CLI

json

{
  "plugins": ["import"],
  "rules": {
    "import/no-unassigned-import": "error"
  }
}

import { defineConfig } from "oxlint";

export default defineConfig({
  plugins: ["import"],
  rules: {
    "import/no-unassigned-import": "error",
  },
});

bash

oxlint --deny import/no-unassigned-import --import-plugin

Version

This rule was added in v0.16.11.

What it does ​

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