ESLint — configuration and usage

This repository uses a single, root ESLint configuration to enforce TypeScript and React best-practices across both the client and server packages.

See the active config at .eslintrc.cjs and the ignore patterns at .eslintignore.

Overview

Parser: @typescript-eslint/parser with tsconfigRootDir set to the repo root.
Plugins: @typescript-eslint, import, react, react-hooks.
Extends: eslint:recommended, plugin:@typescript-eslint/recommended, plugin:import/recommended, plugin:import/typescript, plugin:react/recommended.
Import resolver is configured for TypeScript projects so path resolution works across packages/*/tsconfig.json.

@typescript-eslint/explicit-module-boundary-types: error
- Requires explicit return types on exported functions/exports. This aligns with the repo's TypeScript guideline to keep public API types explicit.
@typescript-eslint/no-explicit-any: error
- Disallows any except where explicitly permitted by overrides (config files and some test helpers). Prefer unknown + type-guards instead.
@typescript-eslint/triple-slash-reference: error
- Enforces using import style typing for tests (Vitest) rather than triple-slash references.
@typescript-eslint/no-unused-vars with _-prefix ignore
- Allows intentionally unused args/vars when prefixed with _.
no-console: ['warn', { allow: ['warn','error'] }]
- Console is warned by default but allowed for warn/error. The server override further relaxes this to support logging middleware.
import/no-unresolved: error
- Ensures imports resolve correctly; some import checks are pragmatically disabled in overrides where false-positives occurred.

packages/client/src/**/*.{ts,tsx}
- env: browser/node. Type-aware linting uses packages/client/tsconfig.json.
- Disables import/no-named-as-default-member where it produced false positives for certain imports.
packages/server/src/**/*.{ts,tsx}
- env: node. Type-aware linting uses packages/server/tsconfig.json.
- Pragmatic relaxations: allow CommonJS require usage in a few places, disable some import/* checks that produced false positives, and allow console for structured logging in middleware/services.
Tests: **/*.test.ts, **/*.test.tsx, tests/**
- Test environment uses standard ES2021 globals; import/no-extraneous-dependencies is turned off for test files.
Config files (**/*.config.ts, **/*vite*.ts, **/*vitest*.ts, **/*tailwind*.ts)
- These files are excluded from the strict no-explicit-any rule to ease interop with tooling configs (the codebase still prefers typed configs where practical).

Install deps (if not already installed):

npm install

Run the workspace lint scripts (this runs per-package lint commands):

npm run lint

Autofix common issues across the repo:

npx eslint . --ext .ts,.tsx --fix

If you want to lint only a package (faster iteration):

npm run lint --workspace=packages/client
npm run lint --workspace=packages/server

You may see a warning from @typescript-eslint about TypeScript version compatibility (this repo uses a newer TypeScript than the parser's tested range). To silence that and ensure deterministic behaviour, either:
- Align typescript with the tested versions for the installed @typescript-eslint/* packages, or
- Upgrade @typescript-eslint/* to a release that officially supports your TypeScript version.
The config enforces strict rules (no any, explicit module boundaries). For quick progress, there are scoped overrides for tests and configuration files. Prefer fixing code to conform to the strict rules rather than widening overrides where possible.
Some import/* rules were temporarily relaxed in server/client overrides due to TypeScript resolver mismatches; if you add new path aliases or change tsconfig layouts, update the import/resolver settings in .eslintrc.cjs so stricter import rules can be re-enabled.

Edit the root configuration at .eslintrc.cjs.
Run npx eslint . --ext .ts,.tsx --fix to apply automatic fixes.
Run npm run lint to ensure both packages pass the rules (server runs tsc --noEmit after linting).