eslint-plugin-acrocase

A single ESLint rule, acrocase/acrocase, that keeps acronyms uppercase in identifiers.

Acronyms Consistently Retain Original Case

npm install --save-dev eslint-plugin-acrocase

// eslint.config.js
import acrocase from 'eslint-plugin-acrocase';

export default [
  { plugins: { acrocase }, rules: { 'acrocase/acrocase': ['error'] } },
];

One rule is not a set to curate, so there is no preset config: the line above is the whole setup.

What it does

The web platform keeps acronyms uppercase — innerHTML, XMLDocument, toJSON, encodeURIComponent — and this rule holds your identifiers to the same convention.

const imageURL = 'https://example.com/img.png';
data.toJSON();
class HTTPClient {}

const imageUrl = '…'; // Acronym 'Url' should be 'URL'. Use 'imageURL'.
data.toJson(); //        Acronym 'Json' should be 'JSON'. Use 'toJSON'.
class HttpClient {} //   Acronym 'Http' should be 'HTTP'. Use 'HTTPClient'.

A leading acronym follows the casing of the identifier it starts, so xmlDoc and jsonData are correct as written while HtmlParser is not.

Some abbreviations only look like acronyms. Id is short for "identifier", not an initialism, so userId is correct and userID is reported.

Names declared somewhere else are never reported, because they are not yours to choose: imported bindings, destructuring keys and computed keys.

Report types

• incorrectAcronym — a known acronym appears in titlecase, like Url for URL.
• incorrectException — an abbreviation appears in uppercase, like ID for Id.

Options

| Option | Default | | | ---------- | ------- | - | | acronyms | [] | Additional acronyms to enforce, on top of the dictionary. |

// eslint.config.js
export default [
  {
    plugins: { acrocase },
    rules: { 'acrocase/acrocase': ['error', { acronyms: ['GCP', 'NATS'] }] },
  },
];

Why there is no fix

Renaming an identifier is not a local edit. It means rewriting every reference to it, and the references that decide whether the rename is safe are the ones a linter cannot see: a named export is read by importers in other files, and a property can be reached as o.parseUrl or o['parseUrl'] from anywhere. A fix that rewrote the declaration alone would produce code that still parses and no longer works.

ESLint's own naming rules — camelcase, id-match, id-denylist, id-length — report without fixing for the same reason. Renaming belongs to your editor's rename refactor, which can see the whole project. The message names the identifier to use.

Dictionary

The plugin ships with a dictionary of 139 acronyms drawn from web platform APIs and general programming, along with the exceptions — Id, Intl — that take normal casing despite looking like acronyms.

Requirements

ESLint 9 or later. The package is ESM-only; a CommonJS eslint.config.cjs can still require() it on Node 20.19+ and 22.12+.

License

MIT