eslint-plugin-legion

LEGION-STANDARDS as a lint plugin. One package, two runtimes: it is an ESLint v9+ plugin, and oxlint's jsPlugins runs ESLint plugins as-is, so the same rules with the same diagnostics run under either. CI on this repo proves the two agree on every fixture.

What it enforces: components that render and never think (no state, effects, fetching, handler bodies or projections in a component), zero comments, no React.FC, no enum, no ternaries, no function keyword, guarded context hooks, hydration-safe useState, server-first page/layout files, no literal conditions in JSX, no manual memoization when the React Compiler is on, no service-role client in browser code, a 180-line component cap, any only on declared boundary paths, and lint bypasses that are scoped, named, explained, and impossible for locked rules. See legion-rules for the rule table and the tolerance levels.

oxlint

yarn add -D eslint-plugin-legion oxlint

// .oxlintrc.json
{
  "jsPlugins": ["eslint-plugin-legion"],
  "rules": {
    "legion/no-narrative-comments": "error",
    "legion/no-enum": "error",
  },
}

To get a full preset instead of listing rules, generate the config from legion-rules:

// scripts/sync-oxlintrc.ts
import { writeFileSync } from 'node:fs';
import { strict } from 'legion-rules';

writeFileSync('.oxlintrc.json', JSON.stringify(strict.oxlint, null, 2));

ESLint

yarn add -D eslint-plugin-legion eslint @typescript-eslint/parser

// eslint.config.mjs
import legion from 'eslint-plugin-legion';
import * as tsParser from '@typescript-eslint/parser';

export default [
  {
    files: ['**/*.ts', '**/*.tsx'],
    languageOptions: {
      parser: tsParser,
      parserOptions: { ecmaFeatures: { jsx: true } },
    },
  },
  ...legion.configs.strict,
];

legion.configs.recommended is the softer preset. For your own levels:

import { legionEslintConfig } from 'eslint-plugin-legion';

export default [
  ...legionEslintConfig({ rules: { 'no-enum': 3 }, noTernary: 2 }),
];

Pass { typescriptEslint: tsPlugin } as the second argument to also wire @typescript-eslint/no-explicit-any with the boundary overrides.

The bypass

A rule at level 2 can be bypassed on one line, and only like this:

// oxlint-disable-next-line legion/no-enum -- generated by the API client

File-wide disables, unnamed disables, disables without a reason, and any disable of a rule at level 3 fail lint through legion/scoped-disables. The one shape no lint rule can see, a bare /* eslint-disable */ at the top of a file, is caught by legion-audit directives; put it in front of your linter in the lint script.

Requirements

Node 22 or newer. Peer: oxlint >= 1.53 (JS plugins) or eslint >= 9, both optional. No runtime dependencies beyond legion-rules.

MIT, Copyright (c) 2026 Veracium LLC.