[cloud_functions] - Internal Exception invisible to the user

[rishabnayak]

Error Details

The _region variable is returned as null and causes an internal exception invisible to the user,

PlatformException(-1, The operation couldn’t be completed. (com.google.GTMSessionFetcher error -1.), null).

How to Reproduce

1. Setup an application and a callable cloud function
2. Try calling the function. It fails with an internal error. On further inspection, shows that the region isn't set.

Logs

Logs don't show anything, the only errors that pop up are

Beginning a fetch requires a request with a URL
[  +16 ms] flutter: throwing generic exception
[   +9 ms] [VERBOSE-2:ui_dart_state.cc(148)] Unhandled Exception: Exception: Unable to call function detectIntent
...

[zoechi]

Possible duplicate of #17677

[asoseil]

same issue with 1.2.1 stable and cloud_function 0.1.0+

[aytunch]

@zoechi Günter, this is not a duplicate.
After downgrading from the current version:
cloud_functions: ^0.1.1+1
to:
cloud_functions: 0.1.0+1

we can successfully call the callable cloud function.

@rishab2113 I don't think there should be an exception in the first place. I guess something was broken with the 0.1.1+1. Because I am running the simplest callable function and it was giving me an error. Once I downgraded, it disappeared.

[rishabnayak]

@aytunch @zoechi This issue is most likely caused by this commit, which tried to solve flutter/flutter#24333.

I did some of my own debugging and found out that the internal variable _region doesn't return successfully, leading to the error. Since this was introduced by PR 1210, I believe it was the culprit, as that commit correlated with the version roll to 0.1.1; also confirmed by a git blame.

It can probably be fixed by a null check on the variable, reverting it to the default us-central1.

Edit: Opening a PR