Firebase Functions https call does not work on emulator - firebase

Question

When executing the https call on the firebase emulator i only get a FirebaseFunctionException. Every other function, except the https call, works fine. When connecting to firebase without the emulator everything works as well. I can´t find a solution for this on the internet, can someone please help?
Method call:
try {
HttpsCallable callable =
FirebaseFunctions.instance.httpsCallable('getBookData');
final results = await callable.call(parameters);
Init:
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
...
final localHostString = Platform.isAndroid ? '10.0.2.2' : 'localhost';
// dotenv.get('HOST_IP');
FirebaseFunctions.instance
.useFunctionsEmulator('http://$localHostString', 5001);
FirebaseFirestore.instance.settings = Settings(
host: '$localHostString:8080',
sslEnabled: false,
persistenceEnabled: false,
);
await auth.FirebaseAuth.instance.useEmulator(
Platform.isAndroid ? 'http://localhost:9099' : 'http://0.0.0.0:9099');
}
Exception:
code:"unavailable"
details:null
message:"UNAVAILABLE"
plugin:"firebase_functions"
stackTrace:#0 StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:607:7)
#1 MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:156:18)
<asynchronous suspension>
#2 MethodChannelHttpsCallable.call (package:cloud_functions_platform_interface/src/method_channel/method_channel_https_callable.dart:23:24)
<asynchronous suspension>
#3 HttpsCallable.call (package:cloud_functions/src/https_callable.dart:35:37)
<asynchronous suspension>
#4 BookRequest._requestBooksFromCloudFunction (package:bookR/shared/bookRequest.dart:47:23)
<asynchronous suspension>
#5 BookRequest.getMoreBooksByTitle (package:bookR/shared/bookRequest.dart:23:24)
<asynchronous suspension>
#6 BookRequest.getBookInformationByTitle (package:bookR/shared/bookRequest.dart:37:13)
<asynchronous suspension>
#7 SearchBar.build.<anonymous closure> (package:bookR/widgets/searchBar.dart:34:28)
<asynchronous suspension>
hashCode:439854717
runtimeType:Type (FirebaseFunctionsException)

Answer 1

I finally figured it out! :D
In case somebody finds this in the future:
FirebaseFunctions.instance
.useFunctionsEmulator('http://$localHostString', 5001);
This causes the error. The correct version is:
FirebaseFunctions.instance
.useFunctionsEmulator('$localHostString', 5001);
Now erverthing works as expected