sort-maps

Enforce sorted elements within JavaScript Map object.

Sorting elements within JavaScript Map objects provides a clear and predictable structure to the codebase. This rule detects instances where Map elements are not sorted and raises linting errors, encouraging developers to arrange elements in the desired order.

By maintaining a consistent structure across Map objects, this rule improves readability and makes it easier to locate and understand key-value pairs.

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.

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 members of maps into logical groups. This can help in organizing and maintaining large maps 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[] — A list of regexp patterns to specify which comments should act as delimiters.

partitionByNewLine

_{default: false}

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

new Map([
     // Group 1
    ['Drone', 0],
    ['Keyboard', 1],
    ['Mouse', 3],
    ['Smartphone', 4],

    // Group 2
    ['Laptop', 5],
    ['Monitor', 6],
    ['Smartwatch', 7],
    ['Tablet', 8],

    // Group 3
    ['Headphones', 9],
    ['Router', 10],
  ])

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

Usage

Version

This rule was introduced in v0.5.0.