merge(ci): ESLint config + GitHub Actions build/test/lint gate

Author: jjohare

.eslintrc.json

@@ -0,0 +1,41 @@
+{
+  "root": true,
+  "env": {
+    "browser": true,
+    "webextensions": true,
+    "serviceworker": true,
+    "es2022": true
+  },
+  "parserOptions": {
+    "ecmaVersion": 2022,
+    "sourceType": "module"
+  },
+  "extends": "eslint:recommended",
+  "rules": {
+    "no-eval": "error",
+    "no-implied-eval": "error",
+    "no-undef": "error",
+    "no-unused-vars": [
+      "warn",
+      {
+        "argsIgnorePattern": "^_",
+        "varsIgnorePattern": "^_",
+        "caughtErrorsIgnorePattern": "^_"
+      }
+    ]
+  },
+  "ignorePatterns": [
+    "node_modules/",
+    "dist/",
+    "**/*.bundle.js"
+  ],
+  "overrides": [
+    {
+      "files": ["test/**/*.js", "scripts/**/*.js"],
+      "env": {
+        "node": true,
+        "browser": false
+      }
+    }
+  ]
+}

.github/workflows/ci.yml

@@ -0,0 +1,35 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  build-test-lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build
+        run: npm run build
+
+      - name: Test
+        run: npm test
+
+      - name: Lint
+        run: npm run lint