feat(metrics): return metrics instance from metrics functions

[dothomson]

Summary

Changes

Please provide a summary of what's being changed

This is a Quality of Life improvement when using a metrics instance. By returning the class instance from some of the functions of the Metrics class then commands can be grouped together and improve readability of the code.

#4929

Issue number: closes #4929

---

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

Disclaimer: We value your time and bandwidth. As such, any pull requests created on non-triaged issues might not be successful.

[boring-cyborg]

Thanks a lot for your first contribution! Please check out our contributing guidelines and don't hesitate to ask whatever you need.
In the meantime, check out the #typescript channel on our Powertools for AWS Lambda Discord: Invite link

[svozza]

I don't think we need to change all the tests to use this new interface, I would prefer if we kept a mixture to show that both usages are still acceptable. Also, I think we should update one of the e2e tests to use the fluent interface too.

[svozza]

Hi @dothomson, just checking in to see if you need any help with the PR?

[dothomson]

@svozza - Apologies I got drawn back into the day job.

I've reverted some of the tests to provided a mixture of the fluid and verbose versions in the tests and updated some of the e2e tests also. I didn't apply any rubric to which tests use which version - let me know if you'd like to apply one or if this random approach was suitable.

---

I was meaning to ask are you happy with the metric functions selected to return the Metrics class?

Generally speaking I wanted to make it easy to define and add and publish metrics, but avoid including "destructive" actions (i.e.clearDimensions) to avoid more confusing function chains.

[svozza]

Absolutely no need to apologise! These changes look good. I'm running the end-to-end tests now and the metrics test suites have already passed so we're looking good there.

Regarding the selection of methods, I think your reasoning is sound: t would be quite starange to do something like metrics.addDimension( ... ).addDeimesnion ( ... ).clearDimensions();. Furthermore, this is something we could always add later if there is some use case we've missed even though I doubt we have.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[svozza]

Thank you @dothomson! Merging now.

[boring-cyborg]

Awesome work, congrats on your first merged pull request and thank you for helping improve everyone's experience!