Build: Make Migrate properly recognized as a CommonJS module in Node.js

PR gh-512 added the `"type": "module"` field to the top-level `package.json`,
making Node-based workflows fail when trying to require Migrate as it's not
exposed as ESM. To fix this, add a small `package.json` with just
`"type": "commonjs"`. Also, add Node.js smoke tests as the simplest way to
verify this change.

Fixes gh-523
Closes gh-525
Ref gh-512

.github/workflows/node.js.yml

@@ -9,6 +9,32 @@ env:
   NODE_VERSION: 20.x
 
 jobs:
+  node-smoke-test:
+    runs-on: ubuntu-latest
+    name: Node smoke tests
+    steps:
+      - name: Checkout
+        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+
+      - name: Use Node.js ${{ env.NODE_VERSION }}
+        uses: actions/setup-node@1e60f620b9541d16bece96c5465dc8ee9832be0b # v4.0.3
+        with:
+          node-version: ${{ env.NODE_VERSION }}
+
+      - name: Cache
+        uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
+        with:
+          path: ~/.npm
+          key: ${{ runner.os }}-node-${{ env.NODE_VERSION }}-npm-lock-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-${{ env.NODE_VERSION }}-npm-lock-
+
+      - name: Install dependencies
+        run: npm install
+
+      - name: Run Node smoke tests
+        run: npm run test:node_smoke_tests
+
   test:
     runs-on: ubuntu-latest
     name: ${{ matrix.MIGRATE_VERSION }} - jQuery ${{ matrix.JQUERY_VERSION }} (Chrome/Firefox)

.gitignore

@@ -10,7 +10,11 @@ CDN
 .sizecache.json
 .eslintcache
 
-/dist
+# Ignore built files in `dist` folder
+# Leave package.json
+/dist/*
+!/dist/package.json
+
 /external
 /node_modules
 

dist/package.json

@@ -0,0 +1,3 @@
+{
+	"type": "commonjs"
+}