sort-array-includes

Enforce sorted array values when immediately used with .includes(...).

Keeping arrays sorted improves scanability and reduces mistakes in membership checks.

Config

ts

pluginRules: {
  sort-array-includes: [warn, { type: alphabetical, order: asc, ignoreCase: true }],
}

Options:

type: alphabetical | natural | line-length | custom | unsorted (default: alphabetical)
order: asc | desc (default: asc)
ignoreCase: boolean (default: true)
specialCharacters: keep | trim | remove (default: keep)
alphabet: string (default: ) — only when type=custom
partitionByNewLine: boolean (default: false)

Note: Heuristic detection; focuses on literal arrays directly followed by .includes(...).

Example

Before:

ts

function getProductCategories(product) {
  if ([
    Mouse,
    Drone,
    Smartphone,
    Keyboard,
    Tablet,
    Monitor,
    Laptop,
    Smartwatch,
    Router,
    Headphones,
  ].includes(product.name)) {
    return Electronics
  }
  return Unknown
}

After (alphabetical asc):

ts

if ([
  Drone,
  Headphones,
  Keyboard,
  Laptop,
  Monitor,
  Mouse,
  Router,
  Smartphone,
  Smartwatch,
  Tablet,
].includes(product.name)) { /* ... */ }

Best practices

Use natural when values include numeric suffixes (e.g., item2, item10)
Consider partitionByNewLine: true to preserve logical grouping inside long arrays
Keep at warn to surface unsorted lists without blocking