Fix metrics for GRPC streams do not correctly include tags when stream ends

[cchamplin]

What?

Update the grpc stream being call to pass tags and params that include custom tags and method information

Why?

Addresses #3745

Checklist

• I have performed a self-review of my code.
• I have added tests for my changes.
• I have run linter locally (make lint) and all checks pass.
• I have run tests locally (make tests) and all tests pass.
• I have commented on my code, particularly in hard-to-understand areas.

Related PR(s)/Issue(s)

#3745

Closes #3745

[CLAassistant]

All committers have signed the CLA.

[olegbespalov]

Hi @cchamplin

Good catch! Thank you for your contribution!

The change looks good to me, but it is also essential to introduce the test for it. It could be similar to something from the cmd_run_grpc_test.go, and the getSampleValues could be used to extract metrics/tags.

Do you think you could address this, or should we consider splitting a test into a separate issue or pull request?

[olegbespalov]

@cchamplin just double-checking if you don't have the capacity for the tests? I could take over; one thing is, could you please maybe name the case? I mean which metrics missed the custom tags? Thanks!

[joanlopez]

Pushing to https://github.com/grafana/k6/milestone/42 while waiting for news.

[cchamplin]

@olegbespalov @joanlopez I have added the test as requested, let me know if that works.

[olegbespalov]

@cchamplin great, thanks! I left the last comment about simplifying the logic. Apart from that, it seems green from my side 👍

[joanlopez]

Hey @cchamplin,
Could you try to address what @olegbespalov suggested, please?
Once done, I think we'll be ready to merge it. Thanks! 🙇🏻

[olegbespalov]

Okay, we could merge this as it's and update the test in a separate PR. Thanks for the contribution!