feat(functions): support custom domains

packages/functions/e2e/functions.e2e.js

@@ -51,6 +51,24 @@ describe('functions()', function () {
       const response = await functionRunner();
       response.data.should.equal(region);
     });
+
+    it('accepts passing in a custom url string as first arg to an app', async function () {
+      const customUrl = 'https://us-central1-react-native-firebase-testing.cloudfunctions.net';
+      const functionsForRegion = firebase.app().functions(customUrl);
+
+      functionsForRegion._customUrlOrRegion.should.equal(customUrl);
+      functionsForRegion.app.should.equal(firebase.app());
+      functionsForRegion.app.name.should.equal(firebase.app().name);
+
+      firebase.app().functions(customUrl).app.should.equal(firebase.app());
+
+      firebase.app().functions(customUrl)._customUrlOrRegion.should.equal(customUrl);
+
+      const functionRunner = functionsForRegion.httpsCallable('testFunctionDefaultRegion');
+
+      const response = await functionRunner();
+      response.data.should.equal('null');
+    });
   });
 
   it('useFunctionsEmulator', async function () {

packages/functions/ios/RNFBFunctions/RNFBFunctionsModule.m

@@ -33,8 +33,8 @@ @implementation RNFBFunctionsModule
 
   RCT_EXPORT_METHOD(httpsCallable:
     (FIRApp *) firebaseApp
-        region:
-        (NSString *) region
+        customUrlOrRegion:
+        (NSString *) customUrlOrRegion
         origin:
         (NSString *) origin
         name:
@@ -48,7 +48,13 @@ @implementation RNFBFunctionsModule
         rejecter:
         (RCTPromiseRejectBlock) reject
   ) {
-    FIRFunctions *functions = [FIRFunctions functionsForApp:firebaseApp region:region];
+
+    NSURL *url = [NSURL URLWithString:customUrlOrRegion];
+    FIRFunctions *functions = (url && url.scheme && url.host) ? [FIRFunctions functionsForApp:firebaseApp customDomain:customUrlOrRegion] : [FIRFunctions functionsForApp:firebaseApp region:customUrlOrRegion];
+
+
+
+
 
     if (origin != nil) {
       [functions useFunctionsEmulatorOrigin:origin];

packages/functions/lib/index.d.ts

@@ -390,7 +390,7 @@ declare module '@react-native-firebase/app' {
       >;
     }
     interface FirebaseApp {
-      functions(region?: string): FirebaseFunctionsTypes.Module;
+      functions(customUrlOrRegion?: string): FirebaseFunctionsTypes.Module;
     }
   }
 }