Pubsub emulator with v1 doesn't work

Environment details

• OS: MacOS
• Node.js version: 12
• npm version: Latest yarn 1.x
• @google-cloud/pubsub version: Latest

Steps to reproduce

Using the synchronous pull example, the PusSub emulator doesn’t seem to be working. It’s as the env variable PUBSUB_EMULATOR_HOST is being ignored.

Also,

with the default emulator local host (localhost:8085), if I do:

const subClient = new v1.SubscriberClient({
  apiEndpoint: 'localhost:8085',
});

I am getting the error:

Error: Failed to parse target localhost:8085:443
        at Function.getDefaultAuthority (/node_modules/@grpc/grpc-js/src/resolver-dns.ts:313:11)
        at Object.getDefaultAuthority (/node_modules/@grpc/grpc-js/src/resolver.ts:134:28)
        at new ChannelImplementation (/node_modules/@grpc/grpc-js/src/channel.ts:199:31)
        at new Client (/node_modules/@grpc/grpc-js/src/client.ts:82:30)
        at new ServiceClientImpl (/node_modules/@grpc/grpc-js/src/make-client.ts:104:3)
        at GrpcClient.createStub (/node_modules/google-gax/src/grpc.ts:306:18)
        at processTicksAndRejections (internal/process/task_queues.js:93:5)

[rlucioni]

@feywind this is also preventing my team from working with the Pub/Sub emulator locally, which makes development difficult. The workarounds proposed in https://github.com/googleapis/nodejs-pubsub/issues/346 don’t work.

[feywind]

Here are some ways to work around this, based on my testing:

The simplest, but probably also the most prone to breakage over time (these aren’t the same types, but they do technically contain the same things):

const pubsubClient = new PubSub();
const subClient = new v1.SubscriberClient(pubsubClient.options);

That will actually pick up the emulator environment variable in the normal way, since it’s just using the PubSub class’ init.

The specific members could be copied like so, to be a bit less breakable:

const pubsubClient = new PubSub();
const subClient = new v1.SubscriberClient({
  apiEndpoint: pubsubClient.options.apiEndpoint,
  port: pubsubClient.options.port,
  sslCreds: pubsubClient.options.sslCreds
});

You could also manually init the options, though I understand that wasn’t working for some:

const grpc = require('@grpc/grpc-js');

const subClient = new v1.SubscriberClient({
  apiEndpoint: 'localhost',
  port: '8085',
  sslCreds: grpc.credentials.createInsecure()
});

(And of course requires app logic, which may not be great.)

I also feel obligated to note that digging into PubSub.options isn’t really a public interface, so that could change whenever. I think probably the good long term solution for this is still the unified environment variables plus gapic client support for it. If it looks like the timeline is long on that, then I suppose another option would be to expose a “give me a client” method on PubSub.

Let me know if anything in there seems like it works, or if you have any ideas about making an interface that works better for you.