Add test workflow

Check for uncommitted Prettier changes

.github/workflows/test.yml

@@ -0,0 +1,24 @@
+name: Test branch
+
+on: push
+
+concurrency:
+  group:
+    ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+      - name: Install dependencies
+        run: npm ci
+      - name: Check for uncommitted Prettier changes
+        run: npm run prettier:ci

package.json

@@ -4,6 +4,10 @@
   "description": "Reusable Prettier config for projects by @anthony-j-castro.",
   "private": true,
   "main": ".prettierrc.json",
+  "scripts": {
+    "prettier": "prettier . --write",
+    "prettier:ci": "prettier . --check"
+  },
   "keywords": [
     "prettier",
     "prettierconfig"