sort-enums
Enforce sorted TypeScript enum members.
Enums are essential for defining a set of named constants, and keeping them in a consistent and predictable order is a best practice for readability and maintainability.
This rule ensures that TypeScript enum members are sorted, making it easier to reason about their values and identify any missing or duplicate entries. Sorted enums enhance the clarity of your code, making it more straightforward to understand and maintain.
Try it out
enum Priority {
Critical = 'Critical',
None = 'None',
Low = 'Low',
High = 'High',
Medium = 'Medium',
}
enum Status {
InProgress = 'In Progress',
Completed = 'Completed',
OnHold = 'On Hold',
Cancelled = 'Cancelled',
NotStarted = 'Not Started',
}
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.
sortByValue
default:falseControls whether sorting should be done using the enum’s values or names.
true— Use enum values.false— Use enum names.
When this setting is true, numeric enums will have their values sorted numerically regardless of the type setting.
forceNumericSort
default:falseControls whether numeric enums should always be sorted numerically, regardless of the type and sortByValue settings.
true— Use enum values.false— Use enum names.
partitionByComment
default:falseEnables the use of comments to separate the members of enums into logical groups. This can help in organizing and maintaining large enums by creating partitions within the enum 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 enum if there is an empty line between them. This helps maintain the defined order of logically separated groups of members.
enum Enum {
// Group 1
C = 'C',
D = 'D',
// Group 2
B = 'B',
// Group 3
A = 'A',
E = 'E',
}Each group of enum 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.
groups
type: Array<string | string[]>
[]Specifies a list of groups for sorting. Groups help organize elements into categories.
Each element 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.
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
type: Array<CustomGroupDefinition | CustomGroupAnyOfDefinition>
[]Defines custom groups to match specific elements.
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
elementNamePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
}
An enum 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<{
elementNamePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
}>
}An enum 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.elementNamePattern— If entered, will check that the name of the element matches the pattern entered.elementValuePattern— If entered, will check that the value of the element 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.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.
Usage
// .eslintrc.js
module.exports = {
plugins: [
'perfectionist',
],
rules: {
'perfectionist/sort-enums': [
'error',
{
type: 'alphabetical',
order: 'asc',
fallbackSort: { type: 'unsorted' },
ignoreCase: true,
specialCharacters: 'keep',
partitionByComment: false,
partitionByNewLine: false,
newlinesBetween: 'ignore',
sortByValue: false,
forceNumericSort: false,
groups: [],
customGroups: [],
},
],
},
}
Version
This rule was introduced in v0.8.0.