Support Params as inputs in eventTrigger (#168)

### Description

The api of the manifest changed in [email protected]. Some inputs have been updated to be T | Expression<T>.
This PR addresses those issues

## Code sample

* Updated a test to include StringParam
* Updated a test to include TernaryExpression

Author: TheIronDev

package-lock.json

@@ -47,7 +47,7 @@
     "@types/mocha": "^5.2.7",
     "chai": "^4.2.0",
     "firebase-admin": "^10.1.0",
-    "firebase-functions": "^3.22.0",
+    "firebase-functions": "^3.23.0",
     "firebase-tools": "^8.9.2",
     "mocha": "^6.2.2",
     "prettier": "^1.19.1",
@@ -57,7 +57,7 @@
   },
   "peerDependencies": {
     "firebase-admin": ">=6.0.0",
-    "firebase-functions": ">=3.22.0",
+    "firebase-functions": ">=3.23.0",
     "jest": ">=28.0.0"
   },
   "engines": {

package.json

@@ -33,6 +33,7 @@ import {
   eventarc,
   https,
 } from 'firebase-functions/v2';
+import { defineString } from 'firebase-functions/v2/params';
 import { makeDataSnapshot } from '../src/providers/database';
 
 describe('v2', () => {
@@ -372,6 +373,39 @@ describe('v2', () => {
           expect(cloudEvent.ref).equal('foo/bar/baz');
         });
 
+        it('should resolve default ref given StringParam', () => {
+          process.env.rtdb_ref = 'foo/StringParam/baz';
+          const referenceOptions = {
+            ref: '',
+            instance: 'instance-1',
+          };
+          const cloudFn = database.onValueCreated(referenceOptions, handler);
+          cloudFn.__endpoint.eventTrigger.eventFilterPathPatterns.ref = defineString(
+            'rtdb_ref'
+          );
+          const cloudFnWrap = wrapV2(cloudFn);
+          const cloudEvent = cloudFnWrap().cloudEvent;
+          expect(cloudEvent.ref).equal('foo/StringParam/baz');
+        });
+
+        it.skip('should resolve default ref given TernaryExpression', () => {
+          const ref1 = defineString('rtdb_ref_1');
+          process.env.rtdb_ref_1 = 'foo/StringParam/1';
+          const ref2 = defineString('rtdb_ref_2');
+          process.env.rtdb_ref_2 = 'foo/StringParam/2';
+          const referenceOptions = {
+            ref: '',
+            instance: 'instance-1',
+          };
+          const cloudFn = database.onValueCreated(referenceOptions, handler);
+          cloudFn.__endpoint.eventTrigger.eventFilterPathPatterns.ref = ref1
+            .equals('aa')
+            .then('rtdb_ref_1', 'rtdb_ref_2');
+          const cloudFnWrap = wrapV2(cloudFn);
+          const cloudEvent = cloudFnWrap().cloudEvent;
+          expect(cloudEvent.ref).equal('rtdb_ref_2');
+        });
+
         it('should resolve using params', () => {
           const referenceOptions = {
             ref: 'users/{user}',

spec/v2.spec.ts

@@ -1,10 +1,11 @@
 import { CloudFunction, database } from 'firebase-functions/v2';
+import { Expression } from 'firebase-functions/v2/params';
 import { DeepPartial } from '../../types';
 import {
   exampleDataSnapshot,
   exampleDataSnapshotChange,
 } from '../../../providers/database';
-import { getBaseCloudEvent } from '../helpers';
+import { resolveStringExpression, getBaseCloudEvent } from '../helpers';
 import { Change } from 'firebase-functions';
 import { makeDataSnapshot } from '../../../providers/database';
 
@@ -117,18 +118,20 @@ export function getCommonDatabaseFields(
     >
   >
 ) {
-  const instance =
+  const instanceOrExpression =
     (cloudEventPartial?.instance as string) ||
     cloudFunction.__endpoint?.eventTrigger?.eventFilterPathPatterns?.instance ||
     cloudFunction.__endpoint?.eventTrigger?.eventFilters?.instance ||
     'instance-1';
+  const instance = resolveStringExpression(instanceOrExpression);
   const firebaseDatabaseHost =
     (cloudEventPartial?.firebaseDatabaseHost as string) ||
     'firebaseDatabaseHost';
-  const rawRef =
+  const rawRefOrExpression =
     (cloudEventPartial?.ref as string) ||
     cloudFunction?.__endpoint?.eventTrigger?.eventFilterPathPatterns?.ref ||
     '/foo/bar';
+  const rawRef = resolveStringExpression(rawRefOrExpression);
   const location = (cloudEventPartial?.location as string) || 'us-central1';
   const params: Record<string, string> = cloudEventPartial?.params || {};
   const ref = extractRef(rawRef, params);

src/cloudevent/mocks/database/helpers.ts

@@ -1,4 +1,5 @@
 import { CloudEvent, CloudFunction } from 'firebase-functions/v2';
+import { Expression } from 'firebase-functions/v2/params';
 
 export const APP_ID = '__APP_ID__';
 export const PROJECT_ID = '42';
@@ -10,7 +11,7 @@ export function getEventType(cloudFunction: CloudFunction<any>): string {
 
 export function getEventFilters(
   cloudFunction: CloudFunction<any>
-): Record<string, string> {
+): Record<string, string | Expression<string>> {
   return cloudFunction?.__endpoint?.eventTrigger?.eventFilters || {};
 }
 
@@ -27,6 +28,15 @@ export function getBaseCloudEvent<EventType extends CloudEvent<unknown>>(
   } as EventType;
 }
 
+export function resolveStringExpression(
+  stringOrExpression: string | Expression<string>
+) {
+  if (typeof stringOrExpression === 'string') {
+    return stringOrExpression;
+  }
+  return stringOrExpression?.value();
+}
+
 function makeEventId(): string {
   return (
     Math.random()

src/cloudevent/mocks/helpers.ts

@@ -3,6 +3,7 @@ import { CloudFunction, CloudEvent } from 'firebase-functions/v2';
 import { StorageEvent } from 'firebase-functions/v2/storage';
 import {
   FILENAME,
+  resolveStringExpression,
   getBaseCloudEvent,
   getEventFilters,
   getEventType,
@@ -14,10 +15,11 @@ export const storageV1: MockCloudEventAbstractFactory<StorageEvent> = {
     cloudFunction: CloudFunction<StorageEvent>,
     cloudEventPartial?: DeepPartial<StorageEvent>
   ): StorageEvent {
-    const bucket =
+    const bucketOrExpression =
       cloudEventPartial?.bucket ||
       getEventFilters(cloudFunction)?.bucket ||
       'bucket_name';
+    const bucket = resolveStringExpression(bucketOrExpression);
     const source =
       cloudEventPartial?.source ||
       `//storage.googleapis.com/projects/_/buckets/${bucket}`;