Add JavaScript linting with Prettier configuration

Co-authored-by: martinemde <[email protected]>

Author: Copilot

.github/workflows/lint.yml

@@ -44,6 +44,21 @@ jobs:
           bundler-cache: true
       - name: Importmap Verify
         run: bundle exec rake importmap:verify
+  prettier:
+    name: Prettier
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          persist-credentials: false
+      - uses: actions/setup-node@0a44ba7841725637a19e28fa30b79a866c81b0a6 # v4.0.4
+        with:
+          node-version: '20'
+          cache: 'npm'
+      - name: Install dependencies
+        run: npm ci
+      - name: Check JavaScript formatting
+        run: npm run lint:js
   kubeconform:
     name: Kubeconform
     runs-on: ubuntu-24.04

.gitignore

@@ -28,3 +28,4 @@ REVISION
 /doc/erd.*
 /app/assets/builds/*
 !/app/assets/builds/.keep
+node_modules/

.prettierignore

@@ -0,0 +1,19 @@
+# Dependencies
+node_modules/
+
+# Build outputs
+public/assets/
+vendor/
+
+# Temporary files
+tmp/
+
+# Test reports
+reports/
+
+# Log files
+*.log
+
+# Lock files
+package-lock.json
+yarn.lock

.prettierrc

@@ -0,0 +1,12 @@
+{
+  "printWidth": 80,
+  "tabWidth": 2,
+  "useTabs": false,
+  "semi": true,
+  "singleQuote": false,
+  "quoteProps": "as-needed",
+  "trailingComma": "es5",
+  "bracketSpacing": true,
+  "bracketSameLine": false,
+  "arrowParens": "always"
+}

CONTRIBUTING.md

@@ -159,6 +159,20 @@ can try running:
 
     bundle exec rake rubocop:autocorrect
 
+#### Running JavaScript Formatting
+
+We use Prettier to enforce consistent JavaScript code style throughout the project.
+Please ensure any JavaScript changes conform to our style standards or else the
+build will fail.
+
+Check JavaScript formatting:
+
+    npm run lint:js
+
+To automatically fix JavaScript formatting issues:
+
+    npm run format
+
 #### Importing gems into the database
 
 * Import gems into the database with Rake task.

package-lock.json

@@ -0,0 +1,16 @@
+{
+  "name": "rubygems-org",
+  "version": "1.0.0",
+  "description": "JavaScript tooling for RubyGems.org",
+  "private": true,
+  "scripts": {
+    "format": "npx prettier --write 'app/javascript/**/*.js' 'config/*.js'",
+    "lint:js": "npx prettier --check 'app/javascript/**/*.js' 'config/*.js'"
+  },
+  "devDependencies": {
+    "prettier": "^3.0.0"
+  },
+  "engines": {
+    "node": ">=18.0.0"
+  }
+}