ESLint Import Extension Validator

Configure ESLint to validate import statement file extensions according to project-specific rules.

Overview

You need to configure ESLint with rules that enforce consistent usage of file extensions in import statements. Some projects require explicit extensions, while others omit them - your configuration should enforce the chosen convention.

Requirements

Extension Rule Configuration

Create an ESLint configuration file (.eslintrc.json) that:

• Enforces explicit .js extensions for all relative imports
• Enforces explicit .json extensions for JSON file imports
• Never requires extensions for npm package imports
• Reports violations as errors

Validation Logic

The configuration must validate:

• ES6 import statements: import foo from './bar'
• CommonJS require statements: const foo = require('./bar')
• Both relative paths (./ and ../) and package imports

Test Files

Create a test file (test.js) that demonstrates:

• A valid import with proper .js extension: import helper from './helper.js'
• A valid package import without extension: import lodash from 'lodash'
• An invalid import missing .js extension (should be caught by linting)

Test Cases

The following test cases verify the configuration works correctly:

• Running ESLint on a file with import './module' (missing .js) reports an error @test
• Running ESLint on a file with import './module.js' reports no errors @test
• Running ESLint on a file with import 'lodash' (package import) reports no errors @test
• Running ESLint on a file with require('./config') (missing .json for JSON file) reports an error @test

Implementation

@generates

API

{
  "extends": ["..."],
  "rules": {
    "import/extensions": ["error", "always", {
      "ignorePackages": true
    }]
  }
}

Dependencies { .dependencies }

eslint-plugin-import { .dependency }

Provides the import/extensions rule for validating import statement file extensions

@satisfied-by