@ign-junn/code-rules

The code rules shared by the Junn React applications (IGN): the junn-rules command, which checks what Biome does not cover, a shared Biome configuration and a base TypeScript configuration. It replaces the check:rules scripts copied from one repository to the next (junn-apps, junn-design-system, flowbench, the junn-publication site).

bun add -d @ign-junn/code-rules

The command

// package.json
"scripts": {
  "check:rules": "junn-rules",
  "fix:rules": "junn-rules --fix"
}

Run from the root of the project, on the TypeScript files of src/. --fix adds the missing blank lines before return; --list lists the rules; --config <file> reads another configuration file.

| Rule | What it enforces | |---|---| | syntax | Arrow functions only, no let, no for / while loop | | html-tags | No HTML tag in JSX (.tsx): components with their component prop | | hardcoded-text | No accented text in the code: texts in the translations (textAllowed excepted) | | negated-optional-chain | No !x?.y: a type guard, then the positive case | | typeof-compare | No typeof x === '…' outside the shared type guards (typeofAllowed) | | blank-line-before-return | A blank line before every return (fixed by --fix) | | declaration-order | In a function: library hooks, application hooks, values, functions, return | | design-system | app: the design system components instead of Mantine's, its single entry, its icons; library: its own components outside their files, no translation library | | import-boundaries | The imports each folder may not use (imports) | | forbidden-files | Files that may not exist (forbiddenFiles) |

Configuration

In the junnRules field of package.json, or in junn-rules.config.json. Every field is optional:

{
  "junnRules": {
    "src": "src",
    "ignore": ["src/api/generated/**"],
    "textAllowed": ["src/locales/**", "src/tests/**"],
    "typeofAllowed": ["src/types/common.ts"],
    "designSystem": "app",
    "imports": [
      { "files": "src/components/**", "forbid": ["@/features/", "@/services/"] },
      { "files": "src/utils/**", "forbid": ["@/features/", "@/components/"], "except": ["src/utils/router.tsx"] }
    ],
    "forbiddenFiles": [{ "files": "src/services/**/*.tsx", "message": "no JSX in services" }],
    "off": []
  }
}

• designSystem: app (default) for an application, library for the design system itself (then wrappers: the files that wrap a Mantine component), false to skip the check.
• off: names of rules to turn off.

Shared configurations

// biome.json
{ "extends": ["@ign-junn/code-rules/biome"], "vcs": { "enabled": true, "clientKind": "git", "useIgnoreFile": true } }

// tsconfig.app.json
{
  "extends": "@ign-junn/code-rules/tsconfig",
  "compilerOptions": { "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.app.tsbuildinfo", "paths": { "@/*": ["./src/*"] } },
  "include": ["src"]
}

Develop

bun install
bun run check      # Biome
bun run typecheck  # TypeScript
bun test           # the rules on throw-away projects

Published by hand in the public npm organization ign-junn, as the design system (cp .env.example .env, paste the token, npm version <patch|minor|major>, bun run release, git push --follow-tags).