eslint plugin angular

ESLint rules for your angular project with checks for best-practices, conventions or potential errors.

Summary

This repository will give access to new rules for the ESLint tool. You should use it only if you are developing an AngularJS application.

Since the 0.0.4 release, some rules defined in John Papa's Guideline have been implemented. In the description below, you will have a link to the corresponding part of the guideline, in order to have more information.

Contents

• Usage with shareable config
• Usage without shareable config
• Rules
• Need your help
• How to create a new rule
• Default ESLint configuration file
• Who uses it?
• Team

Usage with shareable config

Users may use the shareable eslint-config-angular to quickly setup eslint-plugin-angular. It also marks Angular as a global variable and defines required ESLint rules to use this plugin.

1. Install eslint as a dev-dependency:

   npm install --save-dev eslint

2. Install eslint-plugin-angular as a dev-dependency:

   npm install --save-dev eslint-plugin-angular

3. Install eslint-config-angular as a dev-dependency:

   npm install --save-dev eslint-config-angular

4. Use the shareable config by adding it to your .eslintrc:

   extends: angular

Usage without shareable config

1. Install eslint as a dev-dependency:

   npm install --save-dev eslint

2. Install eslint-plugin-angular as a dev-dependency:

   npm install --save-dev eslint-plugin-angular

3. Enable the plugin by adding it to your .eslintrc:

   plugins:
     - angular

4. You can also configure these rules in your .eslintrc. All rules defined in this plugin have to be prefixed by 'angular/'

   plugins:
     - angular
   rules:
     - angular/controller_name: 0

Rules

Rules in eslint-plugin-angular are divided into several categories to help you better understand their value.

Possible Errors

The following rules detect patterns that can lead to errors.

• module-getter - disallow to reference modules with variables and require to use the getter syntax instead angular.module('myModule') (y022)
• module-setter - disallow to assign modules to variables (linked to module-getter (y021)
• no-private-call - disallow use of internal angular properties prefixed with $$

Best Practices

These are rules designed to prevent you from making mistakes. They either prescribe a better way of doing something or help you avoid footguns..

• component-limit - limit the number of angular components per file (y001)
• controller-as-route - require the use of controllerAs in routes or states (y031)
• controller-as-vm - require and specify a capture variable for this in controllers (y032)
• controller-as - disallow assignments to $scope in controllers (y031)
• deferred - use $q(function(resolve, reject){}) instead of $q.deferred
• di-unused - disallow unused DI parameters
• directive-restrict - disallow any other directive restrict than 'A' or 'E' (y074)
• empty-controller - disallow empty controllers
• no-controller - disallow use of controllers (according to the component first pattern)
• no-inline-template - disallow the use of inline templates
• no-run-logic - keep run functions clean and simple (y171)
• no-services - disallow DI of specified services for other angular components ($http for controllers, filters and directives)
• on-watch - require $on and $watch deregistration callbacks to be saved in a variable
• prefer-component -

Deprecated Angular Features

These rules prevent you from using deprecated angular features.

• no-cookiestore - use $cookies instead of $cookieStore
• no-directive-replace - disallow the deprecated directive replace property
• no-http-callback - disallow the $http methods success() and error()

Naming

These rules help you to specify several naming conventions.

• component-name - require and specify a prefix for all component names
• controller-name - require and specify a prefix for all controller names (y123, y124)
• directive-name - require and specify a prefix for all directive names (y073, y126)
• file-name - require and specify a consistent component name pattern (y120, y121)
• filter-name - require and specify a prefix for all filter names
• module-name - require and specify a prefix for all module names (y127)
• service-name - require and specify a prefix for all service names (y125)

Conventions

Angular often provide multi ways to to something. These rules help you to define convention for your project.

• di-order - require DI parameters to be sorted alphabetically
• di - require a consistent DI syntax
• dumb-inject - unittest inject functions should only consist of assignments from injected values to describe block variables
• function-type - require and specify a consistent function style for components ('named' or 'anonymous') (y024)
• module-dependency-order - require a consistent order of module dependencies
• no-service-method - use factory() instead of service() (y040)
• one-dependency-per-line - require all DI parameters to be located in their own line
• rest-service - disallow different rest service and specify one of '$http', '$resource', 'Restangular'
• watchers-execution - require and specify consistent use $scope.digest() or $scope.apply()

Angular Wrappers

These rules help you to enforce the usage of angular wrappers.

• angularelement - use angular.element instead of $ or jQuery
• definedundefined - use angular.isDefined and angular.isUndefined instead of other undefined checks
• document-service - use $document instead of document (y180)
• foreach - use angular.forEach instead of native Array.prototype.forEach
• interval-service - use $interval instead of setInterval (y181)
• json-functions - use angular.fromJson and 'angular.toJson' instead of JSON.parse and JSON.stringify
• log - use the $log service instead of the console methods
• no-angular-mock - require to use angular.mock methods directly
• no-jquery-angularelement - disallow to wrap angular.element objects with jQuery or $
• timeout-service - use $timeout instead of setTimeout (y181)
• typecheck-array - use angular.isArray instead of typeof comparisons
• typecheck-date - use angular.isDate instead of typeof comparisons
• typecheck-function - use angular.isFunction instead of typeof comparisons
• typecheck-number - use angular.isNumber instead of typeof comparisons
• typecheck-object - use angular.isObject instead of typeof comparisons
• typecheck-string - use angular.isString instead of typeof comparisons
• window-service - use $window instead of window (y180)

Need your help

It is an opensource project. Any help will be very useful. You can :

• Create issue
• Send Pull Request
• Write Documentation
• Add new Features
• Add new Rules
• Improve the quality
• Reply to issues

All development happens on the development branch. This means all pull requests should be made to the development branch.

If it is time to release, @Gillespie59 will bump the version in package.json, create a Git tag and merge the development branch into master. @Gillespie59 will then publish the new release to the npm registry.

How to create a new rule

We appreciate contributions and the following notes will help you before you open a Pull Request.

Check the issues

Have a look at the existing issues. There may exist similar issues with useful information.

Read the documentation

There are some useful references for creating new rules. Specificly useful are:

• The Context Object - This is the most basic understanding needed for adding or modifying a rule.
• Options Schemas - This is the preferred way for validating configuration options.
• Scope - This is the scope object returned by context.getScope().

Files you have to create

• rules/<your-rule>.js
  • JavaScript file with the new rule
  • The filename <your-rule> is exactly the usage name in eslint configs angular/<your-rule>
  • Have a look at the angularRule wrapper and the utils (both in rules/utils/) - they probably make things easier for you
  • Add a documentation comment to generate a markdown documentation with the gulp docs task
• test/<your-rule>.js
  • Write some tests and execute them with gulp test
  • Have a look at the coverage reports coverage/lcov-report/index.html
• examples/<your-rule>.js
  • Add some examples for the documentation
  • Run the gulp docs task to test the examples and update the markdown documentation
• docs/<your-rule>.md
  • Generated by the gulp docs task

Files you have to touch

• index.js
  • Add your rule rulesConfiguration.addRule('<your-rule>', [0, {someConfig: 'someValue'}])

Before you open your PR

• Check that the gulp task is working
• Commit generated changes in README.md and docs/<your-rule>.md
• Open your PR to the development branch NOT master

Rules specific for Angular 1 or 2

We can use a property, defined in the ESLint configuration file, in order to know which version is used : Angular 1 or Angular 2. based on this property, you can create rules for each version.

plugins:
  - angular

rules:
    angular/controller-name:
      - 2
      - '/[A-Z].*Controller$/'

globals:
    angular: true

settings:
    angular: 2

And in your rule, you can access to this property thanks to the context object :

//If Angular 2 is used, we disabled the rule
if(context.settings.angular === 2){
    return {};
}

return {

    'CallExpression': function(node) {
    }
};

Default ESLint configuration file

Here is the basic configuration for the rules defined in the ESLint plugin, in order to be compatible with the guideline provided by @johnpapa :

rules:
    no-use-before-define:
      - 0

Who uses it?

• argo
• generator-gillespie59-angular
• generator-ng-poly
• JHipster
• generator-gulp-angular

Team

Emmanuel Demey	Tilman Potthof	Remco Haszing