eslint-plugin-ember

What is eslint-plugin-ember?

eslint-plugin-ember is an ESLint plugin that provides linting rules specific to Ember.js applications. It helps developers follow best practices and maintain consistency in their Ember.js codebase.

What are eslint-plugin-ember's main functionalities?

Best Practices

This rule enforces the best practice of avoiding the use of observers in Ember.js applications. Observers can lead to unpredictable behavior and are generally discouraged.

module.exports = {
  rules: {
    'ember/no-observers': 'error'
  }
};

Stylistic Issues

This rule ensures that developers use Ember's `get` and `set` methods for property access and assignment, which is a stylistic convention in Ember.js.

module.exports = {
  rules: {
    'ember/use-ember-get-and-set': 'error'
  }
};

Ember-Specific Rules

This rule disallows the use of jQuery in Ember.js applications, encouraging developers to use native DOM APIs or Ember's own abstractions.

module.exports = {
  rules: {
    'ember/no-jquery': 'error'
  }
};

Other packages similar to eslint-plugin-ember

eslint-plugin-react

eslint-plugin-react provides linting rules for React applications. It helps enforce best practices and coding standards specific to React, similar to how eslint-plugin-ember does for Ember.js.

eslint-plugin-vue

eslint-plugin-vue offers linting rules for Vue.js applications. It ensures that Vue.js code adheres to best practices and stylistic conventions, much like eslint-plugin-ember does for Ember.js.

eslint-plugin-angular

eslint-plugin-angular provides linting rules for Angular applications. It helps maintain code quality and consistency in Angular projects, similar to the role of eslint-plugin-ember in Ember.js projects.

README

eslint-plugin-ember

An ESLint plugin that provides a set of rules for Ember applications based on commonly known good practices.

❗️Requirements

• ESLint >= 8
• Node.js 18.* || 20.* || >= 21

🚀 Usage

1. Install plugin

npm install --save-dev eslint-plugin-ember

2. Update your config

// eslint.config.js (flat config)
const eslintPluginEmberRecommended = require('eslint-plugin-ember/configs/recommended');

module.exports = [
  ...eslintPluginEmberRecommended,
];

or

// .eslintrc.js (legacy config)
module.exports = {
  plugins: ['ember'],
  extends: [
    'eslint:recommended',
    'plugin:ember/recommended' // or other configuration
  ],
  rules: {
    // override / enable optional rules
    'ember/no-replace-test-comments': 'error'
  }
};

gts/gjs

lint files having First-Class Component Templates (fcct)

learn more here

[!NOTE] special care should be used when setting up parsers, since they cannot be overwritten. thus they should be used in override only and specific to file types

gjs/gts support is provided by the ember-eslint-parser

[!NOTE] if you import .gts files in .ts files, then ember-eslint-parser is required for .ts as well to enable typed linting

// .eslintrc.js
module.exports = {
  overrides: [
    {
      files: ['**/*.{js,ts}'],
      plugins: ['ember'],
      parser: '@typescript-eslint/parser',
      extends: [
        'eslint:recommended',
        'plugin:ember/recommended', // or other configuration
      ],
      rules: {
        // override / enable optional rules
        'ember/no-replace-test-comments': 'error'
      }
    },
    {
      files: ['**/*.gts'],
      parser: 'ember-eslint-parser',
      plugins: ['ember'],
      extends: [
        'eslint:recommended',
        'plugin:@typescript-eslint/recommended',
        'plugin:ember/recommended',
        'plugin:ember/recommended-gts',
      ],
    },
    {
      files: ['**/*.gjs'],
      parser: 'ember-eslint-parser',
      plugins: ['ember'],
      extends: [
        'eslint:recommended',
        'plugin:ember/recommended',
        'plugin:ember/recommended-gjs',
      ],
    },
    {
      files: ['tests/**/*.{js,ts,gjs,gts}'],
      rules: {
        // override / enable optional rules
        'ember/no-replace-test-comments': 'error'
      }
    },
  ],
};

rules applied to fcct templates

• semi rule, same as prettier plugin
• no-undef rule will take effect for template vars (includes js scope)
• no-unused rule will take effect for template block params

rules in templates can be disabled with eslint directives with mustache or html comments:

<template>
  <div>
    {{!eslint-disable-next-line}}
    {{test}}
  </div>
  <div>
    {{!--eslint-disable--}}
    {{test}}
    {{test}}
    {{test}}
    {{!--eslint-enable--}}
  </div>
</template>

<template>
  <div>
    <!--eslint-disable-next-line-->
    {{test}}
  </div>
  <div>
    <!-- eslint-disable -->
    {{test}}
    {{test}}
    {{test}}
    <!-- eslint-enable -->
  </div>
</template>

🧰 Configurations

	Name
	base
✅	recommended
	recommended-gjs
	recommended-gts

🍟 Rules

💼 Configurations enabled in.
✅ Set in the recommended configuration.
Set in the recommended-gjs configuration.
Set in the recommended-gts configuration.
🔧 Automatically fixable by the --fix CLI option.
💡 Manually fixable by editor suggestions.

Components

Name	Description	💼	🔧	💡
no-attrs-in-components	disallow usage of this.attrs in components	✅
no-attrs-snapshot	disallow use of attrs snapshot in the didReceiveAttrs and didUpdateAttrs component hooks	✅
no-classic-components	enforce using Glimmer components	✅
no-component-lifecycle-hooks	disallow usage of "classic" ember component lifecycle hooks. Render modifiers or custom functional modifiers should be used instead.	✅
no-on-calls-in-components	disallow usage of on to call lifecycle hooks in components	✅
require-tagless-components	disallow using the wrapper element of a component	✅

Computed Properties

Name	Description	💼	🔧	💡
computed-property-getters	enforce the consistent use of getters in computed properties
no-arrow-function-computed-properties	disallow arrow functions in computed properties	✅
no-assignment-of-untracked-properties-used-in-tracking-contexts	disallow assignment of untracked properties that are used as computed property dependencies	✅	🔧
no-computed-properties-in-native-classes	disallow using computed properties in native classes	✅
no-deeply-nested-dependent-keys-with-each	disallow usage of deeply-nested computed property dependent keys with @each	✅
no-duplicate-dependent-keys	disallow repeating computed property dependent keys	✅	🔧
no-incorrect-computed-macros	disallow incorrect usage of computed property macros	✅	🔧
no-invalid-dependent-keys	disallow invalid dependent keys in computed properties	✅	🔧
no-side-effects	disallow unexpected side effects in computed properties	✅
no-volatile-computed-properties	disallow volatile computed properties	✅
require-computed-macros	require using computed property macros when possible	✅	🔧
require-computed-property-dependencies	require dependencies to be declared statically in computed properties	✅	🔧
require-return-from-computed	disallow missing return statements in computed properties	✅
use-brace-expansion	enforce usage of brace expansion in computed property dependent keys	✅

Controllers

Name	Description	💼	🔧	💡
alias-model-in-controller	enforce aliasing model in controllers
avoid-using-needs-in-controllers	disallow using needs in controllers	✅
no-controllers	disallow non-essential controllers

Deprecations

Name	Description	💼	🔧	💡
closure-actions	enforce usage of closure actions	✅
new-module-imports	enforce using "New Module Imports" from Ember RFC #176	✅
no-array-prototype-extensions	disallow usage of Ember's Array prototype extensions		🔧
no-at-ember-render-modifiers	disallow importing from @ember/render-modifiers	✅
no-deprecated-router-transition-methods	enforce usage of router service transition methods	✅	🔧
no-function-prototype-extensions	disallow usage of Ember's function prototype extensions	✅
no-implicit-injections	enforce usage of implicit service injections	✅	🔧
no-mixins	disallow the usage of mixins	✅
no-new-mixins	disallow the creation of new mixins	✅
no-observers	disallow usage of observers	✅
no-old-shims	disallow usage of old shims for modules	✅	🔧
no-string-prototype-extensions	disallow usage of String prototype extensions	✅

Ember Data

Name	Description	💼	🔧	💡
no-empty-attrs	disallow usage of empty attributes in Ember Data models
require-async-inverse-relationship	require inverse to be specified in @belongsTo and @hasMany decorators
use-ember-data-rfc-395-imports	enforce usage of @ember-data/ package imports instead ember-data	✅	🔧

Ember Object

Name	Description	💼	🔧	💡
avoid-leaking-state-in-ember-objects	disallow state leakage	✅
no-get	require using ES5 getters instead of Ember's get / getProperties functions	✅	🔧
no-get-with-default	disallow usage of the Ember's getWithDefault function	✅	🔧
no-proxies	disallow using array or object proxies
no-try-invoke	disallow usage of the Ember's tryInvoke util	✅
require-super-in-lifecycle-hooks	require super to be called in lifecycle hooks	✅	🔧
use-ember-get-and-set	enforce usage of Ember.get and Ember.set		🔧

Ember Octane

Name	Description	💼	🔧	💡
classic-decorator-hooks	enforce using correct hooks for both classic and non-classic classes	✅
classic-decorator-no-classic-methods	disallow usage of classic APIs such as get/set in classes that aren't explicitly decorated with @classic	✅
no-actions-hash	disallow the actions hash in components, controllers, and routes	✅
no-classic-classes	disallow "classic" classes in favor of native JS classes	✅
no-ember-super-in-es-classes	disallow use of this._super in ES class methods	✅	🔧
no-empty-glimmer-component-classes	disallow empty backing classes for Glimmer components	✅
no-tracked-properties-from-args	disallow creating @tracked properties from this.args	✅
template-indent	enforce consistent indentation for gts/gjs templates		🔧
template-no-let-reference	disallow referencing let variables in <template>

jQuery

Name	Description	💼	🔧	💡
jquery-ember-run	disallow usage of jQuery without an Ember run loop	✅
no-global-jquery	disallow usage of global jQuery object	✅
no-jquery	disallow any usage of jQuery	✅

Miscellaneous

Name	Description	💼	🔧	💡
named-functions-in-promises	enforce usage of named functions in promises
no-html-safe	disallow the use of htmlSafe
no-incorrect-calls-with-inline-anonymous-functions	disallow inline anonymous functions as arguments to debounce, once, and scheduleOnce	✅
no-invalid-debug-function-arguments	disallow usages of Ember's assert() / warn() / deprecate() functions that have the arguments passed in the wrong order.	✅
no-restricted-property-modifications	disallow modifying the specified properties		🔧
no-runloop	disallow usage of @ember/runloop functions	✅
require-fetch-import	enforce explicit import for fetch()

Routes

Name	Description	💼	🔧	💡
no-capital-letters-in-routes	disallow routes with uppercased letters in router.js	✅
no-controller-access-in-routes	disallow routes from accessing the controller outside of setupController/resetController	✅
no-private-routing-service	disallow injecting the private routing service	✅
no-shadow-route-definition	enforce no route path definition shadowing	✅
no-unnecessary-index-route	disallow unnecessary index route definition
no-unnecessary-route-path-option	disallow unnecessary usage of the route path option	✅	🔧
route-path-style	enforce usage of kebab-case (instead of snake_case or camelCase) in route paths			💡
routes-segments-snake-case	enforce usage of snake_cased dynamic segments in routes	✅

Services

Name	Description	💼	🔧	💡
no-implicit-service-injection-argument	disallow omitting the injected service name argument		🔧
no-restricted-service-injections	disallow injecting certain services under certain paths
no-unnecessary-service-injection-argument	disallow unnecessary argument when injecting services		🔧
no-unused-services	disallow unused service injections (see rule doc for limitations)			💡

Stylistic Issues

Name	Description	💼	🔧	💡
order-in-components	enforce proper order of properties in components		🔧
order-in-controllers	enforce proper order of properties in controllers		🔧
order-in-models	enforce proper order of properties in models		🔧
order-in-routes	enforce proper order of properties in routes		🔧

Testing

Name	Description	💼	🔧	💡
no-current-route-name	disallow usage of the currentRouteName() test helper
no-ember-testing-in-module-scope	disallow use of Ember.testing in module scope	✅
no-invalid-test-waiters	disallow incorrect usage of test waiter APIs	✅
no-legacy-test-waiters	disallow the use of the legacy test waiter APIs	✅
no-noop-setup-on-error-in-before	disallows using no-op setupOnerror in before or beforeEach	✅	🔧
no-pause-test	disallow usage of the pauseTest helper in tests	✅
no-replace-test-comments	disallow 'Replace this with your real tests' comments in test files
no-restricted-resolver-tests	disallow the use of patterns that use the restricted resolver in tests	✅
no-settled-after-test-helper	disallow usage of await settled() right after test helper that calls it internally	✅	🔧
no-test-and-then	disallow usage of the andThen test wait helper	✅
no-test-import-export	disallow importing of "-test.js" in a test file and exporting from a test file	✅
no-test-module-for	disallow usage of moduleFor, moduleForComponent, etc	✅
no-test-support-import	disallow importing of "test-support" files in production code.	✅
no-test-this-render	disallow usage of the this.render in tests, recommending to use @ember/test-helpers' render instead.	✅
prefer-ember-test-helpers	enforce usage of @ember/test-helpers methods over native window methods	✅
require-valid-css-selector-in-test-helpers	disallow using invalid CSS selectors in test helpers	✅	🔧

🍻 Contribution Guide

If you have any suggestions, ideas, or problems, feel free to create an issue, but first please make sure your question does not repeat previous ones.

Creating a New Rule

• Create an issue with a description of the proposed rule
• Create files for the new rule:
  • lib/rules/new-rule.js (implementation, see no-proxies for an example)
  • docs/rules/new-rule.md (documentation, start from the template -- raw, rendered)
  • tests/lib/rules/new-rule.js (tests, see no-proxies for an example)
• Run pnpm update to automatically update the README and other files (and re-run this if you change the rule name or description)
• Make sure your changes will pass CI by running:
  • pnpm test
  • pnpm lint (pnpm lint:js --fix can fix many errors)
• Create a PR and link the created issue in the description

Note that new rules should not immediately be added to the recommended configuration, as we only consider such breaking changes during major version updates.

🔓 License

See the LICENSE file for license rights and limitations (MIT).