added github workflow

.github/workflows/test.yml

@@ -0,0 +1,22 @@
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    name: Perform `firebase emulators:exec "npm run jest"`
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+      - name: Install function modules
+        run: |
+          cd functions
+          npm install
+      - name: Install `firebase-tools` module globally
+        run: npm install -g firebase-tools
+      - name: Run `firebase emulators:exec "npm run jest"`
+        run: firebase emulators:exec "npm run jest"