Add cloud function integration tests

functions/package.json

@@ -6,7 +6,8 @@
     "shell": "firebase functions:shell",
     "start": "npm run shell",
     "deploy": "firebase deploy --only functions",
-    "logs": "firebase functions:log"
+    "logs": "firebase functions:log",
+    "test": "mocha --reporter spec"
   },
   "engines": {
     "node": "16"
@@ -14,9 +15,12 @@
   "main": "index.js",
   "dependencies": {
     "axios": "^1.3.3",
+    "chai": "^4.3.7",
+    "chai-http": "^4.3.0",
     "firebase": "^9.17.1",
     "firebase-admin": "^11.5.0",
     "firebase-functions": "^4.2.0",
+    "mocha": "^10.2.0",
     "xml2js": "^0.4.23"
   },
   "devDependencies": {