sort-variable-declarations

Enforce sorted variable declarations within a scope.

Variable declarations within a block of code can quickly become disorganized and difficult to navigate, especially in larger functions or modules. With this rule, you can ensure that all variable declarations are consistently sorted, making it easier to locate specific variables and maintain a clean and structured codebase.

This practice improves readability and maintainability by providing a predictable order for variable declarations. It helps developers quickly understand the scope and usage of variables without having to search through an unsorted list.

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 variable declarations into logical groups. This can help in organizing and maintaining large variable declaration blocks 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 variable declaration if there is an empty line between them. This can be useful for keeping logically separated groups of members in their defined order.

const
  // Group 1
  fiat = "Fiat",
  honda = "Honda",

  // Group 2
  ferrari = "Ferrari",

  // Group 3
  chevrolet = "Chevrolet",
  ford = "Ford"

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

Usage

Version

This rule was introduced in v3.0.0.