sort-object-types
Enforce sorted object types.
This rule standardizes the order of members within an object type in TypeScript. By ensuring that the members are sorted, it enhances readability without affecting the type system or code behavior.
This practice promotes a clear and consistent structure, making it easier for developers to understand and maintain object types.
Important
If you use the adjacent-overload-signatures rule from the @typescript-eslint/eslint-plugin plugin, it is highly recommended to disable it to avoid conflicts.
Try it out
type Department = {
location: string
departmentName: string
employees: number
head: string
established: Date
}
type Company = {
ceo: string
departments: Department[]
headquarters: string
name: string
industry: string
founded: Date
}
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'
sortBy?: 'name' | 'value'
}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.
sortBy
default:nameSpecifies whether to sort using object type keys or values.
name— Use object types keys.value— Use the values of properties. Non-properties will not have an enforced sort order.
Example
type User = {
createdAt: Date
lastLoginAt: Date
_id: ObjectId
groupId: ObjectId
city: string
}sortBy option configuration:
{
sortBy: 'value',
}
[DEPRECATED] ignorePattern
default:[]Use the useConfigurationIf.declarationMatchesPattern option alongside type: unsorted instead.
Specifies names or patterns for object types to be ignored by this rule. This can be useful if you have specific object types that you do not want to sort.
You can specify their names or a regexp pattern to ignore, for example: '^Component.+' to ignore all object types whose names begin with the word “Component”.
partitionByComment
default:falseEnables the use of comments to separate the members of types into logical groups. This can help in organizing and maintaining large object types by creating partitions 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 an object if there is an empty line between them. This helps maintain the defined order of logically separated groups of members.
type User = {
// Group 1
firstName: string;
lastName: string;
// Group 2
age: number;
birthDate: Date;
// Group 3
address: {
street: string;
city: string;
};
phone?: string;
};Each group of members (separated by empty lines) is treated independently, and the order within each group is preserved.
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.
[DEPRECATED] groupKind
default:'mixed'Use the groups option with the optional and required modifiers instead.
Groups type object keys by their kind, determining whether required values should come before or after optional values.
mixed— Do not group object keys by their kind; required values are sorted together optional values.required-first— Group all required values before optional.optional-first— Group all optional values before required.
useConfigurationIf
type:
{
allNamesMatchPattern?: string | string[] | { pattern: string; flags: string } | { pattern: string; flags: string }[]
declarationMatchesPattern?: string | string[] | { pattern: string; flags: string } | { pattern: string; flags: string }[]
}default: {}Specifies filters to match a particular options configuration for a given object type.
The first matching options configuration will be used. If no configuration matches, the default options configuration will be used.
allNamesMatchPattern— A regexp pattern that all keys must match.
Example configuration:
{
'perfectionist/sort-object-types': [
'error',
{
groups: ['r', 'g', 'b'], // Sort colors types by RGB
customGroups: {
r: '^r$',
g: '^g$',
b: '^b$',
},
useConfigurationIf: {
allNamesMatchPattern: '^r|g|b$',
},
},
{
type: 'alphabetical' // Fallback configuration
}
],
}declarationMatchesPattern— A regexp pattern that the object type declaration must match.
Example configuration:
{
'perfectionist/sort-object-types': [
'error',
{
type: 'unsorted', // Do not sort Metadata types
useConfigurationIf: {
declarationMatchesPattern: '*Metadata$',
},
},
{
type: 'alphabetical' // Fallback configuration
}
],
}groups
type: Array<string | string[]>
[]Specifies a list of type properties groups for sorting. Groups help organize properties into categories, making your type definitions more readable and maintainable.
Each property 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.
Example
type User = {
firstName: string // unknown
lastName: string // unknown
username: string // unknown
job: { // multiline-member
// Stuff about job
}
localization: { // multiline-member
// Stuff about localization
}
}groups option configuration:
{
groups: [
'unknown',
'method',
'multiline-member',
]
}
Index-signatures
- Selectors:
index-signature,member. - Modifiers:
required,optional,multiline. - Example:
optional-index-signature,index-signature,member.
Methods
- Selectors:
method,member. - Modifiers:
required,optional,multiline. - Example:
optional-multiline-method,method,member.
Properties
- Selectors:
property,member. - Modifiers:
required,optional,multiline. - Example:
optional-property,property,member.
Scope of the required modifier
Elements that are not optional will be matched with the required modifier, even if the keyword is not present.
Important notes
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,
it will automatically be added to the end of the list.
Behavior when multiple groups match an element
The lists of modifiers above are sorted by importance, from most to least important. In case of multiple groups matching an element, the following rules will be applied:
- 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 :
interface Test {
optionalMethod?: () => {
property: string;
}
}optionalMethod can be matched by the following groups, from most to least important:
multiline-optional-methodoroptional-multiline-method.multiline-method.optional-method.method.multiline-optional-memberoroptional-multiline-member.multiline-member.optional-member.member.unknown.
Example 2 (The most important group is written in the comments):
interface Interface {
// 'index-signature'
[key: string]: any;
// 'optional-property'
description?: string;
// 'required-method'
method(): stringNewlines 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 is deprecated.
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>
[]Defines custom groups to match specific object type 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'; sortBy?: 'name' | 'value' }
sortBy?: 'name' | 'value'
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 }[]
}
An object type 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'; sortBy?: 'name' | 'value' }
sortBy?: 'name' | 'value'
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 }[]
}>
}An object type 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 properties. If entered, will check that the value of the property matches 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.sortBy— Overrides thesortByoption for that custom groupnewlinesInside— 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.
Example
Put all properties starting with id and name at the top, combine and sort metadata and optional multiline properties at the bottom.
Anything else is put in the middle.
type User = {
id: string // top
name: string // top
age: number // unknown
isAdmin: boolean // unknown
lastUpdated_metadata: Date // bottom
localization?: { // optional-multiline-member
// Stuff about localization
}
version_metadata: string // bottom
}groups and customGroups configuration:
{
groups: [
+ 'top',
'unknown',
+ ['optional-multiline-member', 'bottom']
],
+ customGroups: [
+ {
+ groupName: 'top',
+ selector: 'property',
+ elementNamePattern: '^(?:id|name)$',
+ },
+ {
+ groupName: 'bottom',
+ selector: 'property',
+ elementNamePattern: '.+_metadata$',
+ }
+ ]
}Usage
// .eslintrc.js
module.exports = {
plugins: [
'perfectionist',
],
rules: {
'perfectionist/sort-object-types': [
'error',
{
type: 'alphabetical',
order: 'asc',
fallbackSort: { type: 'unsorted' },
ignoreCase: true,
specialCharacters: 'keep',
sortBy: 'name',
ignorePattern: [],
partitionByComment: false,
partitionByNewLine: false,
newlinesBetween: 'ignore',
useConfigurationIf: {},
groups: [],
customGroups: [],
},
],
},
}
Version
This rule was introduced in v0.11.0.