sort-array-includes

💼 This rule is enabled in the following configs: recommended-alphabetical, recommended-line-length, recommended-natural.

🔧 This rule is automatically fixable by the --fix CLI option.

📖 Rule Details

Enforce sorted array values if the includes method is immediately called after the array is created.

This rule aims to promote code readability and maintainability by enforcing a consistent ordering of values in arrays.

💡 Examples

Alphabetical and Natural Sorting

// ❌ Incorrect
if ([
  'maintainer',
  'admin',
  'developer',
  'owner',
  'observer'
].includes(user.role)) {
  return response.json({ allowed: true })
}

// ✅ Correct
if ([
  'admin',
  'developer',
  'maintainer',
  'observer'
  'owner',
].includes(user.role)) {
  return response.json({ allowed: true })
}

Sorting by Line Length

// ❌ Incorrect
if ([
  'maintainer',
  'admin',
  'developer',
  'owner',
  'observer'
].includes(user.role)) {
  return response.json({ allowed: true })
}

// ✅ Correct
if ([
  'maintainer',
  'developer',
  'observer'
  'admin',
  'owner',
].includes(user.role)) {
  return response.json({ allowed: true })
}

🔧 Options

This rule accepts an options object with the following properties:

interface Options {
  type?: 'alphabetical' | 'natural' | 'line-length'
  order?: 'asc' | 'desc'
  'ignore-case'?: boolean
  'spread-last'?: boolean
}

type

_{(default: 'alphabetical')}

• alphabetical - sort alphabetically.
• natural - sort in natural order.
• line-length - sort by code line length.

order

_{(default: 'asc')}

• asc - enforce properties to be in ascending order.
• desc - enforce properties to be in descending order.

ignore-case

_{(default: false)}

Only affects alphabetical and natural sorting. When true the rule ignores the case-sensitivity of the order.

spread-last

_{(default: false)}

When true enforce spread elements in array to be last.

⚙️ Usage

Legacy Config

// .eslintrc
{
  "plugins": ["perfectionist"],
  "rules": {
    "perfectionist/sort-array-includes": [
      "error",
      {
        "type": "natural",
        "order": "asc",
        "spread-last": true
      }
    ]
  }
}

Flat Config

// eslint.config.js
import perfectionist from 'eslint-plugin-perfectionist'

export default [
  {
    plugins: {
      perfectionist,
    },
    rules: {
      'perfectionist/sort-array-includes': [
        'error',
        {
          type: 'natural',
          order: 'asc',
          spread-last: true,
        },
      ],
    },
  },
]

🚀 Version

This rule was introduced in v0.5.0.

📚 Resources

• Rule source
• Test source