🟡 Functional

Use this preset when you want strict functional-style constraints as your default.

Config key

immutable.configs.functional

Flat Config example

import immutable from "eslint-plugin-immutable-2";

export default [immutable.configs.functional];

functional builds on functional-lite and additionally bans classes, this, throw, try, and bare expression statements while promoting no-method-signature from a migration warning to an error.

Rules in this preset

• Fix legend:
  • 🔧 = autofixable
  • 💡 = suggestions available
  • — = report only

Rule	Fix
immutable-data	—
no-abort-controller-mutation	—
no-atomics-mutation	—
no-buffer-mutation	—
no-cache-api-mutation	—
no-class	—
no-conditional-statement	—
no-cookie-mutation	—
no-data-view-mutation	—
no-date-mutation	—
no-dom-token-list-mutation	—
no-expression-statement	—
no-form-data-mutation	—
no-headers-mutation	—
no-history-mutation	—
no-let	💡
no-location-mutation	—
no-loop-statement	—
no-map-set-mutation	—
no-method-signature	💡
no-mixed-interface	—
no-process-env-mutation	—
no-reflect-mutation	—
no-regexp-lastindex-mutation	—
no-stateful-regexp	—
no-storage-mutation	—
no-this	—
no-throw	—
no-try	—
no-typed-array-mutation	—
no-url-mutation	—
no-url-search-params-mutation	—
readonly-array	🔧
readonly-keyword	🔧