Perfectionist

sort-objects

Enforce sorted objects.

By adhering to this rule, developers can ensure that object keys are consistently sorted, leading to cleaner and more maintainable code. This rule promotes a standardized key ordering across objects, making it easier to navigate and understand the structure of objects within the codebase.

It’s safe. The rule considers spread elements in objects and does not break component functionality.

Important

If you use the sort-keys rule, it is highly recommended to disable it to avoid conflicts.

Try it out

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 the length of the code line (shorter lines first).
  • 'custom' — Sort items using the alphabet entered in the alphabet option.
  • 'unsorted' — Do not sort items. To be used with the useConfigurationIf option.

order

default: 'asc'

Determines whether the sorted items should be 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).

alphabet

default: ''

Only used when the type option is set to 'custom'. Specifies the custom alphabet to use when sorting.

Use the Alphabet utility class from eslint-plugin-perfectionist/alphabet to quickly generate a custom alphabet.

Example: 0123456789abcdef...

ignoreCase

default: true

Controls whether sorting should be case-sensitive or not.

  • 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: keep

Controls whether special characters should be trimmed, removed or kept 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. See 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: false

Allows you to use comments to separate the keys of objects into logical groups. This can help in organizing and maintaining large objects by creating partitions based on comments.

  • true — All comments will be treated as delimiters, creating partitions.
  • false — Comments will not be used as delimiters.
  • string — A regexp pattern to specify which comments should act as delimiters.
  • string[] — An array of regexp patterns to specify which comments should act as delimiters.

partitionByNewLine

default: false

When true, the rule will not sort the object’s keys if there is an empty line between them. This can be useful for keeping logically separated groups of keys in their defined order.

const user = {
  // Group 1
  firstName: 'John',
  lastName: 'Doe',

  // Group 2
  age: 30,
  birthDate: '1990-01-01',

  // Group 3
  email: 'john.doe@example.com',
  phone: '555-555-5555'
};

Each group of keys (separated by empty lines) is treated independently, and the order within each group is preserved.

newlinesBetween

default: 'ignore'

Specifies how new lines should be handled between object groups.

  • ignore — Do not report errors related to new lines between object groups.
  • always — Enforce one new line between each group, and forbid new lines inside a group.
  • never — No new lines are allowed in objects.

This options is only applicable when partitionByNewLine is false.

styledComponents

default: true

Determines whether this rule should be applied to styled-components like libraries or style JSX attribute.

  • true — Apply the rule to styled-components.
  • false — Disable the rule for styled-components.

ignorePattern

default: []

Allows you to specify names or patterns for object that should be ignored by this rule. This can be useful if you have specific objects that you do not want to sort.

You can specify their names or a regexp pattern to ignore, for example: '^User.+' to ignore all object whose names begin with the word “User”.

[DEPRECATED] destructureOnly

default: false

Use the objectDeclarations and destructuredObjects options instead.

Allows you to only sort objects that are part of a destructuring pattern. When set to true, the rule will apply sorting exclusively to destructured objects, leaving other object declarations unchanged.

objectDeclarations

default: true

Allows you to choose whether to sort standard object declarations.

destructuredObjects

type: boolean | { groups: boolean }

default: true

Allows you to choose whether to sort destructured objects. The groups attribute allows you to specify whether to use groups to sort destructured objects.

useConfigurationIf

type: { allNamesMatchPattern?: string; callingFunctionNamePattern?: string }

default: {}

Allows you to specify filters to match a particular options configuration for a given object.

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 object keys must match.

Example configuration:

{
  'perfectionist/sort-objects': [
    'error',
    {
      groups: ['r', 'g', 'b'], // Sort colors by RGB
      customGroups: {
        r: '^r$',
        g: '^g$',
        b: '^b$',
      },
      useConfigurationIf: {
        allNamesMatchPattern: '^r|g|b$',
      },
    },
    {
      type: 'alphabetical' // Fallback configuration
    }
  ],
}
  • callingFunctionNamePattern — A regexp pattern for matching objects that are passed as arguments to a function with a specific name.
{
  'perfectionist/sort-objects': [
    'error',
    {
      type: 'unsorted', // Don't sort objects passed to createSlice
      useConfigurationIf: {
        callingFunctionNamePattern: '^createSlice$',
      },
    },
    {
      type: 'alphabetical' // Fallback configuration
    }
  ],
}

groups

type: Array<string | string[]>

default: []

Allows you to specify a list of object keys groups for sorting. Groups help organize object keys into categories, making your objects more readable and maintainable.

Predefined groups:

  • 'multiline' — Properties with multiline definitions, such as methods or complex type declarations.
  • 'method' - Members that are methods.
  • 'unknown' — Properties that don’t fit into any group specified in the groups option.

If the unknown group is not specified in the groups option, it will automatically be added to the end of the list.

Each object 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.

customGroups

type: { [groupName: string]: string | string[] }

default: {}

You can define your own groups and use regexp pattern to match specific object keys.

Each key of customGroups represents a group name which you can then use in the groups option. The value for each key can either be of type:

  • string — An object attribute’s name matching the value will be marked as part of the group referenced by the key.
  • string[] — An object attribute’s name matching any of the values of the array will be marked as part of the group referenced by the key. The order of values in the array does not matter.

Custom group matching takes precedence over predefined group matching.

Example

Put all properties starting with id and name at the top, put metadata at the bottom. Regroup multiline and in the middle, above unknown-matched properties.

const user = {
  id: 'id',                   // top
  name: 'John',               // top
  getEmail: () => null,       // method
  localization: {             // multiline
    // Stuff about localization
  },
  age: 40,                    // unknown
  isAdmin: false,             // unknown
  lastUpdated_metadata: null, // bottom
  version_metadata: '1'       // bottom
}

groups and customGroups configuration:

 {
   groups: [
+    'top',
     ['multiline', 'method'],
     ['unknown'],
     'bottom'
   ],
+  customGroups: {              
+    top: ['^id$', '^name$']    
+    bottom: '.+_metadata$'
+  }                            
 }

Usage

Version

This rule was introduced in v0.6.0.

Resources

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