/eslint-plugin-sort-class-members

An ESLint rule for enforcing consistent ES6 class member order

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eslint-plugin-sort-class-members

ESLint rule for enforcing consistent ES6 class member order.

Installation

Install ESLint and eslint-plugin-sort-class-members:

$ npm install eslint eslint-plugin-sort-class-members --save-dev

Note: If you installed ESLint globally (using the -g flag) then you must also install eslint-plugin-sort-class-members globally.

Usage

Add sort-class-members to the plugins section of your .eslintrc configuration file, and configure the rule under the rules section.

{
  "plugins": [
    "sort-class-members"
  ],
  "rules": {
    "sort-class-members/sort-class-members": [2, {
      "order": [
        "[static-properties]",
        "[static-methods]",
        "[properties]",
        "[conventional-private-properties]",
        "constructor",
        "[methods]",
        "[conventional-private-methods]"
      ]
    }]
  }
}

When using the default configuration (shown above), the following patterns are considered problems:

class Foo {
  b = 'bar';

  c(){}

  constructor(){} // error Expected constructor to come before method c

  static a(){} // error Expected static method a to come before property b
}

When using the default configuration (shown above), the following patterns are not considered problems:

class Foo {
  static a(){}

  b = 'bar';

  constructor(){}

  c(){}
}

Configuration

The rule accepts three configuration properties:

  • order: Used to specify the expected sort order of class members.
  • groups: May optionally be used to created customized named groups of members so that order can be more easily maintained. Groups can be referenced by name by using square brackets. E.g., "[group-name]".
  • stopAfterFirstProblem: Only report the first sort problem in each class (plus the number of problems found). Useful if you only want to know that the class has sort problems without spamming error messages. The default is false.
{
  "order": [
    "constructor",
    "[event-handlers]", // reference the custom group defined in the "groups" property
    "[everything-else]" // a few groups are provided by default (see list below)
  ],
  "groups": {
    "event-handlers": [{ "name": "/on.+/", "type": "method" }]
  },
  "stopAfterFirstProblem": false
}

Members can be matched by name (exact match or regexp), by type ("method" or "property"), and by whether or not the member is static. Each match may be described by an object with three properties, all of which are optional.

  • name: a string matching the name of the member. If the string starts and ends with / it will be interpreted as a regular expression. E.g., "/_.+/".
  • type: "method"|"property". Note that class properties currently require a custom parser like babel-eslint.
  • static: true|false to restrict the match to static or instance members.

A few examples:

  • { "name": "create", "type": "method", "static": true } would match a static method named create.
  • { "static": true } would match all static methods and properties.
  • { "name": "/on.+/", "type": "method" } would match both static and instance methods whose names start with "on".
  • "/on.+/" is shorthand for { "name": "/on.+/" }, and would match all static and instance methods and properties whose names start with "on".

Note that you can simply use a string if you only want to match on the name.

The following groups are provided by default:

  • [properties]: matches all properties
  • [static-properties]: matches all static properties
  • [conventional-private-properties]: matches properties whose name starts with an underscore
  • [methods]: matches all methods
  • [static-methods]: matches all static methods
  • [conventional-private-methods]: matches methods whose name starts with an underscore
  • [everything-else]: matches all class members not matched by any other rule

NOTE: Currently only ES2016 property initializers are matched by "type": "property". Properties added via assignment are not considered by this rule.