feat(compiler): Allow consts for decorator arguments

[jttommy]

Allows for consts to be used within Listen and Event decorators through additional type checks in compiler

fixes: #6360

What is the current behavior?

GitHub Issue Number: (#6360)

What is the new behavior?

• Allow @event and @listen decorators to use const variables and nested object constants
• Add comprehensive test coverage with 15 test cases
• Maintain backward compatibility for all existing decorators
• Update type definitions with documentation and examples

Documentation

Does this introduce a breaking change?

• Yes
• No

Testing

• Unit tests
• e2e tests
• Updated some other tests to exclude snapshot testing, which could be faulty. Instead we query DOM objects for precision.

Other information

[johnjenkins]

thanks for contributing @jttommy - looks great!

Do you mind:

1. fixing the formatting issues
2. adding some wdio / component tests for this (inside test/wdio) - specifically a test for shared listener / event variables imported into components would be valuable I think

TYSM

[jttommy]

thanks for contributing @jttommy - looks great!

Do you mind:

1. fixing the formatting issues
2. adding some wdio / component tests for this (inside test/wdio) - specifically a test for shared listener / event variables imported into components would be valuable I think

TYSM

I believe I addressed the issues. WebDriverIO was giving me a lot of problems. I think those tests and that config need some work in another ticket.

[jttommy]

@johnjenkins
There are several failed WebDriver.io tests on main that predate my work. Particularly this:

[chrome 138.0.7204.158 windows #0-0] 1) dom-reattach should have proper values
[chrome 138.0.7204.158 windows #0-0] expect(received).toEqual(expected) // deep equality

- Expected  - 2
+ Received  + 2

- ObjectContaining {
+ Object {
    "parsed": Object {},
    "property": "border",
-   "value": "5px dotted rgb(255, 0, 0)",
+   "value": "4.8px dotted rgb(255, 0, 0)",
  }

It seems the rendered border-width is fairly sensitive and only off by a fraction of a pixel. I think maybe the hardware I'm running on is an issue? Or perhaps there's some other underlying CSS calculation that is off.

Furthermore there is a failed test regarding relative speed, which just assumes styles load quickly. I think this is a smelly test. I've upped the threshold on that timer.

[johnjenkins]

hey thanks for looking at those @jttommy - I would say, as smelly as that test might seem, it's giving off some smoke with this MR.
I've just had a quick look on main and the allowance on it is very generous - it generally clears at around 10ms so for it to now be semi-consistently over 200ms leads me to think there's an issue here.
Could you have a look please?

The wdio test you mentioned doesn't seem to ever be an issue in CI - so, yes probably a local thing.

[jttommy]

hey thanks for looking at those @jttommy - I would say, as smelly as that test might seem, it's giving off some smoke with this MR. I've just had a quick look on main and the allowance on it is very generous - it generally clears at around 10ms so for it to now be semi-consistently over 200ms leads me to think there's an issue here. Could you have a look please?

The wdio test you mentioned doesn't seem to ever be an issue in CI - so, yes probably a local thing.

I updated the code to only apply to @Listen and @Event decorators to limit the scope of the work to what's relevant.

[jttommy]

hey thanks for looking at those @jttommy - I would say, as smelly as that test might seem, it's giving off some smoke with this MR. I've just had a quick look on main and the allowance on it is very generous - it generally clears at around 10ms so for it to now be semi-consistently over 200ms leads me to think there's an issue here. Could you have a look please?
The wdio test you mentioned doesn't seem to ever be an issue in CI - so, yes probably a local thing.

I updated the code to only apply to @Listen and @Event decorators to limit the scope of the work to what's relevant.

@johnjenkins
UPDATE - Aug 18 2025
Tests are all passing now.

[tamb]

@johnjenkins I'm totally stuck on this JSON type error. Idk what the issue is exactly. Could I get some help on it?

[johnjenkins]

hey @tamb - ok will do when I get some time