sort-classes
Enforce sorted class members.
Organizing class members in a consistent order improves both readability and maintainability.
This rule helps developers quickly locate class members and understand the overall structure of the class.
By sorting class members systematically, confusion is minimized, and the code becomes more intuitive to navigate. This practice not only aids in individual productivity but also enhances team collaboration by establishing clear and predictable coding standards.
Try it out
class User {
constructor(username: string, email: string, isActive: boolean) {
this.username = username
this.email = email
this.isActive = isActive
this.roles = []
}
addRole(role: string) {
this.roles.push(role)
}
deactivate() {
this.isActive = false
}
setEmail(newEmail: string) {
this.email = newEmail
}
activate() {
this.isActive = true
}
removeRole(role: string) {
this.roles = this.roles.filter(r => r !== role)
}
getProfile() {
return {
username: this.username,
email: this.email,
isActive: this.isActive,
roles: this.roles,
}
}
}
Options
This rule accepts an options object with the following properties:
type
default:'alphabetical'Specifies the sorting method.
'alphabetical'— Sort items alphabetically (e.g., “a” < “b” < “c”) using localeCompare.'natural'— Sort items in a natural order (e.g., “item2” < “item10”).'line-length'— Sort items by code line length (shorter lines first).'custom'— Sort items using the alphabet specified in thealphabetoption.'unsorted'— Do not sort items.groupingandnewlines behaviorare still enforced.
order
default:'asc'Specifies whether to sort items in ascending or descending order.
'asc'— Sort items in ascending order (A to Z, 1 to 9).'desc'— Sort items in descending order (Z to A, 9 to 1).
fallbackSort
type:
{
type: 'alphabetical' | 'natural' | 'line-length' | 'custom' | 'unsorted'
order?: 'asc' | 'desc'
}default: { type: 'unsorted' }Specifies fallback sort options for elements that are equal according to the primary sort
type.
Example: enforce alphabetical sort between two elements with the same length.
{
type: 'line-length',
order: 'desc',
fallbackSort: { type: 'alphabetical', order: 'asc' }
}alphabet
default:''Used only when the type option is set to 'custom'. Specifies the custom alphabet for sorting.
Use the Alphabet utility class from eslint-plugin-perfectionist/alphabet to quickly generate a custom alphabet.
Example: 0123456789abcdef...
ignoreCase
default:trueSpecifies whether sorting should be case-sensitive.
true— Ignore case when sorting alphabetically or naturally (e.g., “A” and “a” are the same).false— Consider case when sorting (e.g., “a” comes before “A”).
specialCharacters
default:keepSpecifies whether to trim, remove, or keep special characters before sorting.
'keep'— Keep special characters when sorting (e.g., “_a” comes before “a”).'trim'— Trim special characters when sorting alphabetically or naturally (e.g., “_a” and “a” are the same).'remove'— Remove special characters when sorting (e.g., “/a/b” and “ab” are the same).
locales
default:'en-US'Specifies the sorting locales. Refer To String.prototype.localeCompare() - locales.
string— A BCP 47 language tag (e.g.'en','en-US','zh-CN').string[]— An array of BCP 47 language tags.
partitionByComment
default:falseEnables the use of comments to separate the class members into logical groups. This can help in organizing and maintaining large classes by creating partitions within the class based on comments.
true— All comments will be treated as delimiters, creating partitions.false— Comments will not be used as delimiters.RegExpPattern = string | { pattern: string; flags: string}— A regexp pattern to specify which comments should act as delimiters.RegExpPattern[]— A list of regexp patterns to specify which comments should act as delimiters.{ block: boolean | RegExpPattern | RegExpPattern[]; line: boolean | RegExpPattern | RegExpPattern[] }— Specify which block and line comments should act as delimiters.
partitionByNewLine
default:falseWhen true, the rule will not sort the members of a class if there is an empty line between them. This helps maintain the defined order of logically separated groups of members.
class User {
// Group 1
firstName: string;
lastName: string;
// Group 2
age: number;
birthDate: Date;
// Group 3
address: {
street: string;
city: string;
};
phone?: string;
// Group 4
updateAddress(address: string) {}
updatePhone(phone?: string) {}
// Group 5
editFirstName(firstName: string) {}
editLastName(lastName: string) {}
};newlinesBetween
type:number | 'ignore'default: 'ignore'Specifies how to handle newlines between groups.
'ignore'— Do not report errors related to newlines.0— No newlines are allowed.- Any other number — Enforce this number of newlines between each group, and forbid newlines inside groups.
You can also enforce the newline behavior between two specific groups through the groups options.
See the groups option.
This option is only applicable when partitionByNewLine is false.
ignoreCallbackDependenciesPatterns
type: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
[]Specifies regexp patterns of function names that should ignore dependency sorting in their callback functions.
Example with ignoreCallbackDependenciesPatterns: ['^computed$']:
class User {
fullName = computed(() => this.role + ' - ' + this.username);
role = signal('admin');
username = signal('John');
};Without ignoreCallbackDependenciesPatterns: ['^computed$'], role and username would be sorted before fullName as it depends on them.
groups
type: Array<string | string[]>
default:
[
'index-signature',
'static-property',
'static-block',
['protected-property', 'protected-accessor-property'],
['private-property', 'private-accessor-property'],
['property', 'accessor-property'],
'constructor',
'static-method',
'protected-method',
'private-method',
'method',
['get-method', 'set-method'],
'unknown',
]Specifies a list of class member groups for sorting. Groups help organize class members into categories, prioritizing them during sorting.
Each class member will be assigned a single group specified in the groups option (or the unknown group if no match is found).
The order of items in the groups option determines how groups are ordered.
Within a given group, members will be sorted according to the type, order, ignoreCase, etc. options.
Individual groups can be combined together by placing them in an array. The order of groups in that array does not matter. All members of the groups in the array will be sorted together as if they were part of a single group.
Predefined groups are characterized by a single selector and potentially multiple modifiers. You may enter modifiers in any order, but the selector must always come at the end.
Constructors
- Selector:
constructor. - Modifiers:
protected,private,public. - Example:
protected-constructor,private-constructor,public-constructororconstructor.
Methods
- Selectors:
get-method,set-method,method. - Modifiers:
static,abstract,decorated,override,protected,private,public,optional,async. - Example:
private-static-accessor-property,protected-abstract-override-methodorstatic-get-method.
The optional modifier is incompatible with the get-method and set-method selectors.
The abstract modifier is incompatible with the static, private and decorated modifiers.
constructor, get-method and set-method elements will also be matched as method.
Accessors
- Selector:
accessor-property. - Modifiers:
static,abstract,decorated,override,protected,private,public. - Example:
private-static-accessor-property,protected-abstract-override-methodorstatic-get-method.
The abstract modifier is incompatible with the static, private and decorated modifiers.
Properties
- Selectors:
function-property,property. - Modifiers:
static,declare,abstract,decorated,override,readonly,protected,private,public,optional,async. - Example:
readonly-decorated-property.
The abstract modifier is incompatible with the static, private and decorated modifiers.
The declare modifier is incompatible with the override and decorated modifiers.
The function-property selector will match properties whose values are defined functions or arrow-functions.
As such, the declare and abstract modifiers are incompatible with this selector.
The async modifier is reserved for the function-property selector.
Index-signatures
- Selector:
index-signature. - Modifiers:
static,readonly. - Example:
static-readonly-index-signature.
Static-blocks
- Selector:
static-block. - Modifiers: No modifier available.
- Example:
static-block.
Important notes
Scope of the private modifier
The private modifier will currently match any of the following:
- Elements with the
privatekeyword. - Elements with their name starting with
#.
Scope of the public modifier
Elements that are not protected nor private will be matched with the public modifier, even if the keyword is not present.
The unknown group
Members that don’t fit into any group specified in the groups option will be placed in the unknown group. If the unknown group is not specified in the groups option,
the members will remain in their original order.
Behavior when multiple groups match an element
The lists of selectors and modifiers above are both sorted by importance, from most to least important. In case of multiple groups matching an element, the following rules will be applied:
- Selector priority:
constructor,get-methodandset-methodgroups will always take precedence overmethodgroups. - If the selector is the same, the group with the most modifiers matching will be selected.
- If modifiers quantity is the same, order will be chosen based on modifier importance as listed above.
Example 1:
abstract class Class {
protected abstract get field();
}field can be matched by the following groups, from most to least important:
abstract-protected-get-methodorprotected-abstract-get-method.abstract-get-method.protected-get-method.get-method.abstract-protected-methodorprotected-abstract-method.abstract-method.protected-method.method.unknown.
Example 2 (The most important group is written in the comments):
abstract class Example extends BaseExample {
// 'index-signature'
[key: string]: any;
// 'public-static-property'
static instance: Example;
// 'declare-protected-static-readonly-property'
declare protected static readonly value: string;
// 'static-block'
static {
console.log("I am a static block");
}
// 'public-property'
public description: string;
// 'public-decorated-property'
@SomeDecorator
public value: number;
// 'public-decorated-accessor-property'
@SomeDecorator
public accessor value: number;
// 'public-decorated-get-method'
@SomeDecorator
get decoratedValue() {
return this._value;
}
// 'public-decorated-set-method'
@SomeDecorator
set decoratedValue(value: number) {
this._value = value;
}
// 'public-decorated-get-method'
@SomeDecorator
get value() {
return this._value;
}
// 'public-get-method'
get value() {
return this._value;
}
// 'public-set-method'
set value(value: number) {
this._value = value;
}
// 'protected-abstract-override-readonly-decorated-property'
@SomeDecorator
protected abstract override readonly _value: number;
// 'protected-decorated-accessor-property'
@SomeDecorator
protected accessor _value: number;
// 'protected-property'
protected name: string;
// 'protected-decorated-get-method'
@SomeDecorator
protected get value() {
return this._value;
}
// 'private-decorated-property'
@SomeDecorator
private _value: number;
// 'private-decorated-accessor-property'
@SomeDecorator
private accessor _value: number;
// 'private-property'
private name: string;
// 'private-decorated-get-method'
@SomeDecorator
private get value() {
return this._value;
}
// 'public-constructor'
constructor(value: number) {
this._value = value;
}
// 'public-static-method'
static getInstance() {
return this.instance;
}
// 'protected-static-method'
protected static initialize() {
this.instance = new Example(0);
}
// 'private-static-method'
private static initialize() {
this.instance = new Example(0);
}
// 'public-decorated-method'
@SomeDecorator
public decoratedMethod() {
return this._value;
}
// 'public-method'
public display() {
console.log(this._value);
}
// 'protected-method'
protected calculate() {
return this._value * 2;
}
// private-function-property
private arrowProperty = () => {};
// 'private-method'
private calculate() {
return this._value * 2;
}
// private-function-property
private functionProperty = function() {};
}Newlines between groups
You may place newlinesBetween objects between your groups to enforce the newline behavior between two specific groups.
See the newlinesBetween option.
This feature is only applicable when partitionByNewLine is false.
{
newlinesBetween: 1,
groups: [
'a',
{ newlinesBetween: 0 }, // Overrides the global newlinesBetween option
'b',
]
}customGroups
Migrating from the old API
Support for the object-based customGroups option has been removed.
Migrating from the old to the current API is easy:
Old API:
{
"key1": "value1",
"key2": "value2"
}Current API:
[
{
"groupName": "key1",
"elementNamePattern": "value1"
},
{
"groupName": "key2",
"elementNamePattern": "value2"
}
] type: Array<CustomGroupDefinition | CustomGroupAnyOfDefinition>
[]You can define your own groups and use regex for matching very specific class members.
A custom group definition may follow one of the two following interfaces:
interface CustomGroupDefinition {
groupName: string
type?: 'alphabetical' | 'natural' | 'line-length' | 'unsorted'
order?: 'asc' | 'desc'
fallbackSort?: { type: string; order?: 'asc' | 'desc' }
newlinesInside?: number
selector?: string
modifiers?: string[]
elementNamePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
elementValuePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
decoratorNamePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
}A class member will match a CustomGroupDefinition group if it matches all the filters of the custom group’s definition.
or:
interface CustomGroupAnyOfDefinition {
groupName: string
type?: 'alphabetical' | 'natural' | 'line-length' | 'unsorted'
order?: 'asc' | 'desc'
fallbackSort?: { type: string; order?: 'asc' | 'desc' }
newlinesInside?: number
anyOf: Array<{
selector?: string
modifiers?: string[]
elementNamePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
elementValuePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
decoratorNamePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
}>
}A class member will match a CustomGroupAnyOfDefinition group if it matches all the filters of at least one of the anyOf items.
Attributes
groupName— The group’s name, which needs to be put in thegroupsoption.selector— Filter on theselectorof the element.modifiers— Filter on themodifiersof the element. (All the modifiers of the element must be present in that list)elementNamePattern— If entered, will check that the name of the element matches the pattern entered.elementValuePattern— Only for non-function properties. If entered, will check that the value of the property matches the pattern entered.decoratorNamePattern— If entered, will check that at least onedecoratormatches the pattern entered.type— Overrides thetypeoption for that custom group.unsortedwill not sort the group.order— Overrides theorderoption for that custom group.fallbackSort— Overrides thefallbackSortoption for that custom group.newlinesInside— Enforces a specific newline behavior between elements of the group.
Match importance
The customGroups list is ordered:
The first custom group definition that matches an element will be used.
Custom groups have a higher priority than any predefined group. If you want a predefined group to take precedence over a custom group,
you must write a custom group definition that does the same as what the predefined group does (using selector and modifiers filters), and put it first in the list.
Example:
{
groups: [
'static-block',
'index-signature',
+ 'input-properties',
+ 'output-properties',
'constructor',
+ 'unsorted-methods-and-other-properties',
['get-method', 'set-method'],
'unknown',
],
+ customGroups: [
+ {
+ // `constructor()` members must not match
+ // `unsorted-methods-and-other-properties`
+ // so make them match this first
+ groupName: 'constructor',
+ selector: 'constructor',
+ },
+ {
+ groupName: 'input-properties',
+ selector: 'property',
+ modifiers: ['decorated'],
+ decoratorNamePattern: 'Input',
+ },
+ {
+ groupName: 'output-properties',
+ selector: 'property',
+ modifiers: ['decorated'],
+ decoratorNamePattern: 'Output',
+ },
+ {
+ groupName: 'unsorted-methods-and-other-properties',
+ type: 'unsorted',
+ anyOf: [
+ {
+ selector: 'method',
+ },
+ {
+ selector: 'property',
+ },
+ ]
+ },
+ ]
}Usage
// .eslintrc.js
module.exports = {
plugins: [
'perfectionist',
],
rules: {
'perfectionist/sort-classes': [
'error',
{
type: 'alphabetical',
order: 'asc',
fallbackSort: { type: 'unsorted' },
ignoreCase: true,
specialCharacters: 'keep',
partitionByComment: false,
partitionByNewLine: false,
newlinesBetween: 'ignore',
ignoreCallbackDependenciesPatterns: [],
groups: [
'index-signature',
['static-property', 'static-accessor-property'],
['static-get-method', 'static-set-method'],
['protected-static-property', 'protected-static-accessor-property'],
['protected-static-get-method', 'protected-static-set-method'],
['private-static-property', 'private-static-accessor-property'],
['private-static-get-method', 'private-static-set-method'],
'static-block',
['property', 'accessor-property'],
['get-method', 'set-method'],
['protected-property', 'protected-accessor-property'],
['protected-get-method', 'protected-set-method'],
['private-property', 'private-accessor-property'],
['private-get-method', 'private-set-method'],
'constructor',
['static-method', 'static-function-property'],
['protected-static-method', 'protected-static-function-property'],
['private-static-method', 'private-static-function-property'],
['method', 'function-property'],
['protected-method', 'protected-function-property'],
['private-method', 'private-function-property'],
'unknown',
],
customGroups: [],
},
],
},
}
Version
This rule was introduced in v0.11.0.