restrict-identifier-characters

Require identifiers to contain only english characters, digits, underscore, or dollar sign.

Targeted pattern scope

This rule checks all identifier names and reports names containing characters outside this allowed set:

• ASCII letters (A-Z, a-z)
• digits (0-9)
• underscore (_)
• dollar sign ($)

What this rule reports

This rule reports identifiers that include characters outside $, latin letters, digits, and _.

Why this rule exists

It enforces ASCII-only identifier naming for repositories that prioritize uniform tooling behavior and readability across locales.

❌ Incorrect

const абв = 1;

✅ Correct

const $x1 = 2;

Behavior and migration notes

This rule reports only and does not provide an autofix.

Migration usually involves renaming identifiers and adjusting references.

Options

This rule has no options.

Additional examples

function приветствие(): void {}
// ❌ reported

function greetingMessage(): void {}
// ✅ valid

ESLint flat config example

import etcMisc from "eslint-plugin-etc-misc";

export default [
 {
  plugins: { "etc-misc": etcMisc },
  rules: {
   "etc-misc/restrict-identifier-characters": "error",
  },
 },
];

When not to use it

Disable this rule if your codebase allows non-latin identifier names.

Package documentation

• eslint-plugin-etc-misc README

Rule catalog ID: R064

Further reading

• MDN: Lexical grammar (Identifiers)

Adoption resources

• Start at warning level in CI, then move to error after cleanup.
• Use focused codemods/autofix batches per package or directory.