ESLint plugin

Most of what this library can get wrong, it tells you about: conflicting initials, two stores on one name, a payload that fails its schema, a transport that degraded — all of them warn in development with an error code.

Four mistakes cannot warn, because from the inside they are indistinguishable from correct use. A store defined inside a component looks like a store defined anywhere else. A bus name built from a variable is a perfectly good name. A function in shared state is a value like any other until the moment it has to cross the wire. Those four are what this plugin is for.

pnpm add -D eslint-plugin-use-everywhere

eslint.config.js

import useEverywhere from 'eslint-plugin-use-everywhere';

export default [
  // …your config
  useEverywhere.configs.recommended,
];

The config carries no files filter, so put it after any files block of your own if the project mixes languages.

The rules

Rule	Recommended	What it catches
define-at-module-scope	error	defineStore / defineChannel / createNamespace inside a function
no-dynamic-name	error	A bus name computed at runtime
structured-clone-safe	error	Functions, symbols and class instances in shared state
leader-effect-captures	warn	A useLeaderEffect closing over a value that changes between renders

Three are errors: each produces a page that renders, syncs nothing, and says nothing. The fourth is a warning, because a captured value that never actually changes is harmless and no syntactic rule can tell the difference — it argues rather than blocks.

What it deliberately does not do

The rules are syntactic. They read the shape of your code, not its types, which means no parserOptions.project, no typed-linting cost, and no opinion about values it cannot see:

useSharedState('cart', initialFromProps); // not judged — nothing to read

They match on call names, including through a namespace (checkout.defineStore(…)), so any object with a defineStore method is treated as ours. The names are distinctive enough that the trade is worth it.

They also do not replace eslint-plugin-react-hooks. Every hook here is a real hook: rules-of-hooks and exhaustive-deps still apply, and the recommended config assumes you run them.