perf(template-compiler): static-optimize on event listener object

[cardoso]

Details

I'm still getting familiar with the codebase. Hopefully this makes sense. 🤞

Closes #4467

Does this pull request introduce a breaking change?

• 😮‍💨 No, it does not introduce a breaking change.

Does this pull request introduce an observable change?

• 🤞 No, it does not introduce an observable change.

GUS work item

W-16535749

[nolanlawson]

Thanks a bunch for this PR!! Just wanted to let you know what we're a little slammed, but I will take a look this week. 👀

[nolanlawson]

This is looking really great in general! Most of the snapshots look exactly right, and the Karma tests are still passing.

The only issue I found is the edge case of binding to variables defined within for:each loops. We need to handle those so that re-defining the event listeners works correctly (see comment above).

I also added some quick snapshot tests just to confirm that the entire on object is memoized when there are multiple event listeners on the same element.

Thanks a bunch for this PR!! Much appreciated. 🙏

[nolanlawson]

Also, this PR seems to have just nudged us below the 95% target code coverage threshold. Opened a PR that should hopefully help bump it back up: #4482

[cardoso]

@nolanlawson the test in #4480 is very helpful. Thanks!

PS: I copied here in order to validate locally since it wasn't merged yet.

[nolanlawson]

Looking great to me. I'd just love to see another Karma test added and then I'd say

We should get #4480 merged first to avoid merge conflicts.

Thank you very much!! 🙇

[nolanlawson]

/nucleus test

[ekashida]

Thank you!

[nolanlawson]

/nucleus test

[nolanlawson]

The improvement is not as much as I'd hoped, but it's definitely there! Looks to be ~0.5%-6% depending on the benchmark.

[cardoso]

@nolanlawson here's the test for listeners with mixed local & non-local scopes in a single element.

I'll need to send my computer for repair this week, so please take over if I missed anything.

Thank you!

[nolanlawson]

/nucleus test

[nolanlawson]

Thanks again! This is fantastic work. 🥇