sort-switch-case

Enforce sorted switch case statements.

Switch statements with numerous cases can quickly become cumbersome and hard to navigate. With this rule, you can easily locate specific cases and ensure that your codebase adheres to a predictable and standardized format.

This practice contributes to a more readable and maintainable codebase, allowing developers to quickly understand and modify the logic without getting lost in a jumble of unsorted case clauses.

By integrating this rule into your ESLint configuration, you can focus on the functionality of your code, confident that your switch statements are consistently structured and easy to manage.

Try it out

const userReducer = (state = initialState, action) => {
  switch (action.type) {
    case 'FETCH_USER_ERROR':
      return {
        ...state,
        loading: false,
        error: action.payload,
      }
    case 'FETCH_USER_SUCCESS':
      return {
        ...state,
        loading: false,
        currentUser: action.payload,
      }
    case 'DELETE_USER':
      return {
        ...state,
        users: state.users.filter(user => user.id !== action.payload.id),
      }
    case 'FETCH_USER_REQUEST':
      return {
        ...state,
        loading: true,
        error: null,
      }
    case 'ADD_USER':
      return {
        ...state,
        users: [...state.users, action.payload],
      }
    default:
      return state
  }
}

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 the alphabet option.
'unsorted' — Do not sort items.

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: true}

Specifies 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: keep}

Specifies 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.

Usage

// .eslintrc.js
module.exports = {
  plugins: [
    'perfectionist',
  ],
  rules: {
    'perfectionist/sort-switch-case': [
      'error',
      {
        type: 'alphabetical',
        order: 'asc',
        fallbackSort: { type: 'unsorted' },
        ignoreCase: true,
        specialCharacters: 'keep',
      },
    ],
  },
}

Version

This rule was introduced in v3.0.0.