Add basic ESLint config, lint script and lint CI job

.eslintignore

@@ -0,0 +1,4 @@
+dist
+node_modules
+.github
+.changeset

.eslintrc.js

@@ -0,0 +1,54 @@
+module.exports = {
+  root: true,
+  extends: ['eslint:recommended'],
+  plugins: ['no-only-tests'],
+  env: {
+    browser: true,
+    node: true,
+  },
+  parserOptions: {
+    ecmaVersion: 'latest',
+    sourceType: 'module',
+    tsconfigRootDir: __dirname,
+    project: ['./tsconfig.json', './docs/tsconfig.json'],
+  },
+  ignorePatterns: ['**/node_modules/*', '**/dist/*'],
+  rules: {
+    'no-only-tests/no-only-tests': 'warn',
+    'no-mixed-spaces-and-tabs': 'off',
+  },
+  overrides: [
+    {
+      files: ['**/*.ts'],
+      parser: '@typescript-eslint/parser',
+      extends: ['plugin:@typescript-eslint/recommended-type-checked'],
+      rules: {
+        '@typescript-eslint/no-unused-vars': [
+          'warn',
+          {
+            argsIgnorePattern: '^_',
+            destructuredArrayIgnorePattern: '^_',
+            varsIgnorePattern: '^_',
+          },
+        ],
+        '@typescript-eslint/no-non-null-assertion': 'off',
+        '@typescript-eslint/no-redundant-type-constituents': 'off',
+      },
+    },
+    {
+      files: ['**/env.d.ts'],
+      rules: {
+        '@typescript-eslint/triple-slash-reference': 'off',
+      },
+    },
+    {
+      files: ['packages/*/__tests__/**/*.ts'],
+      rules: {
+        '@typescript-eslint/no-unsafe-argument': 'off',
+        '@typescript-eslint/no-unsafe-assignment': 'off',
+        '@typescript-eslint/no-explicit-any': 'off',
+        '@typescript-eslint/no-empty-function': 'off',
+      },
+    },
+  ],
+};

.github/workflows/ci.yml

@@ -30,6 +30,23 @@ jobs:
       - name: Test packages
         run: pnpm -r test:coverage
 
+  lint:
+    name: Lint code
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: pnpm/action-setup@v3
+      - uses: actions/setup-node@v4
+        with:
+          node-version: ${{ env.NODE_VERSION }}
+          cache: 'pnpm'
+      - run: pnpm i
+      - name: Generate types
+        working-directory: ./docs
+        run: pnpm astro sync
+      - name: Run linter
+        run: pnpm lint:ci
+
   pa11y:
     name: Check for accessibility issues
     runs-on: ubuntu-20.04

package.json

@@ -5,6 +5,8 @@
   "description": "",
   "scripts": {
     "build:examples": "pnpm --no-bail --workspace-concurrency 1 --filter '@example/*' build",
+    "lint": "eslint .",
+    "lint:ci": "eslint . --max-warnings 0",
     "size": "size-limit",
     "version": "pnpm changeset version && pnpm i --no-frozen-lockfile",
     "format": "prettier -w --cache --plugin prettier-plugin-astro ."
@@ -14,10 +16,15 @@
     "@changesets/changelog-github": "^0.4.8",
     "@changesets/cli": "^2.26.1",
     "@size-limit/file": "^8.2.4",
+    "@typescript-eslint/eslint-plugin": "^7.3.1",
+    "@typescript-eslint/parser": "^7.3.1",
     "astro": "^4.3.5",
+    "eslint": "^8.53.0",
+    "eslint-plugin-no-only-tests": "^3.1.0",
     "prettier": "^3.0.0",
     "prettier-plugin-astro": "^0.13.0",
-    "size-limit": "^8.2.4"
+    "size-limit": "^8.2.4",
+    "typescript": "^5.4.2"
   },
   "packageManager": "[email protected]",
   "size-limit": [