Functions reports JSON fragment on empty response (i.e. from undeployed function)

[iKK001]

[REQUIRED] Step 1: Describe your environment

• Xcode version: 13.3
• Firebase SDK version: 8.14.0
• Installation method: Swift Package Manager
• Firebase Component: httpscallable Function
• Target platform(s): iOS15.4

[REQUIRED] Step 2: Describe the problem

Trying to run a httpscallable Function I get the following error:

Error Domain=NSCocoaErrorDomain Code=3840 "JSON text did not start with array or object and option to allow fragments not set. around line 2, column 0." UserInfo={NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set. around line 2, column 0., NSJSONSerializationErrorIndex=1}

On Web and Android, the FB-Function runs fine - only on iOS I get the above error message.

Here is my code:

First the more old-fashioned way

functions.httpsCallable("myFBFunctionName").call(["test": "hello"]) { result, error in
  if let error = error {
      print(error)    // see error message above
  }
  if let data = result?.data as? [String: Any], let text = data["invitationCode"] as? String {
    print(text)
  }
}

Or with the more modern SwiftUI way (same error, unfortunately as above):

Task {
    var functions = Functions.functions()    
    do {
        let result = try await functions.httpsCallable("myFBFunctionName").call(["test": "hello"])
        print("result: \(result)")
    } catch {
        print("error: \(error)")   // see error message above
    }
}

How do I call this function in iOS15.4, using SDK 8.14.0 ????

[google-oss-bot]

I found a few problems with this issue:

• I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.
• This issue does not seem to follow the issue template. Make sure you provide all the required information.

[morganchen12]

Can you grab the JSON data and post it here? Feel free to redact any fields, the error is caused only by the structure and not the actual values.

[iKK001]

Which json-data do you mean? According to the Firebase Documentation for Function calls in iOS, I have to provide the following:

functions.httpsCallable("addMessage").call(["text": inputField.text]) { result, error in 
// ... 
}

And this is exactly what I did in my code.

Therefore according to the doc, I have to bring it to the form of ["text": inputField.text] instead of json format.

You ask me for the json-data. Well, how do I get it ? Or is the documentation wrong ? I don't understand yet.

If still json format is necessary inside the function's call() method, then can you please post the correct documentation here and update the Firebase-Doc as well ?
Thank you.

[iKK001]

I am sorry - my mistake: The Firebase Function was NOT YET DEPLOYED. Therefore it is impossible to work.

Too bad the error message is very much misleading tough.

[morganchen12]

Probably the right way to fix this is to wrap the JSON deserialization error in another error to provide more context (with the NSUnderlyingError key). The line is here: https://cs.opensource.google/firebase-sdk/firebase-ios-sdk/+/master:FirebaseFunctions/Sources/Functions.swift;l=346