Hi @HannahShiSFB
I went ahead and fixed some linting issues, to speed the process.
(Just an FYI)

There is this part, where the array union operator is replaced with array_merge(), in Spanner/src/Connection/Grpc.php ie:

$grpcConfig = array_merge(
    $grpcConfig,
    $this->emulatorGapicConfig($config['emulatorHost'])
);

A similar change is also needed in vendor/google/cloud-pubsub/src/Connection/Grpc.php (line 118) (and maybe in other Grpc Connection classes)

That's a good catch, otherwise behavior could change for some implementations!

There is this part, where the array union operator is replaced with array_merge(), in Spanner/src/Connection/Grpc.php ie:

$grpcConfig = array_merge(
    $grpcConfig,
    $this->emulatorGapicConfig($config['emulatorHost'])
);

A similar change is also needed in vendor/google/cloud-pubsub/src/Connection/Grpc.php (line 118) (and maybe in other Grpc Connection classes)

There are 5 emulators in google cloud: Spanner, Firestore, PubSub, Datastore, BigTable. They all have the same issue.
Spanner and BigTable have been fixed by this PR. After testing, I'll fix the other 3.

Hello guys,
Is there any update about this PR? We are looking at it because it is blocking us from using the Firestore emulator.
We would be glad to help if needed. 😉

Hi @jmleroux !

The changes here only effect Spanner. We will need to make additional changes for them to be added to Firestore, PubSub, Datastore, and BigTable. However, this can be done at any time (the changes here will not effect existing behavior).

EDIT: I've added the changes for the other relevant packages in #5250