Angular code generator needs to be verified to work with optional new and const

[leafpetersen]

This is the angular specific issue for #30921 .

[leafpetersen]

We don't seem to have an area-frameworks flag to triage with, should we?

cc @matanlurey

[matanlurey]

Probably an Customer: Frameworks is probably fine, or similar.

[natebosch]

@MichaelRFairhurst is currently investigating a potential breakage. We need to narrow down whether there is an edge case in the analyzer, or in angular/the build systems usage of the analyzer.

[dgrove]

any updates here?

[MichaelRFairhurst]

I have a repro that I've been stepping through, I had at one point thought I'd pinned down the cause but that turned out to be a dead end. Still looking but I'm feeling good about it.

…

[matanlurey]

I saw this on the dart-lang/build gitter:

Source_gen problem...
This work as expected:

@Propagate(const ['id', 'name', 'enabled', 'sex'], const {
    'items': const Propagate(['id', 'type', 'index', 'insertType.id',
    'insertType.name', 'video.id', 'video.name'])
  })

Becomes this DartObject

Propagate (fields = List ([String ('id'), String ('name'), String ('enabled'), String ('sex')]); relationships = Map ({String ('items') = Propagate (fields = List ([String ('id'), String ('type'), String ('index'), String ('insertType.id'), String ('insertType.name'), String ('video.id'), String ('video.name')]); relationships = Null (null); when = Null (null))}); when = Null (null))

When I remove the const keyword from the relationships property

const {
    'items': ...

It becomes this DartObject:

Propagate (fields = List ([String ('id'), String ('name'), String ('enabled'), String ('sex')]); relationships = Null (null); when = Null (null))

The relatshionps property becomes null

[MichaelRFairhurst]

I believe this is fixed with https://dart-review.googlesource.com/c/sdk/+/57000. Going to do my best to try to confirm that, with that fix, there are no remaining issues.

[dgrove]

Any updates?

[MichaelRFairhurst]

I do have some issues I've seen, I thought I had reproed them correctly but found out I was debugging the wrong issue. So I am still working on that.

There's also a DDC issue which may be the same, or different (inside DDC or analyzer).

[MichaelRFairhurst]

the second analyzer issue I found was fixed: https://dart-review.googlesource.com/c/sdk/+/58800

the DDC issue is still outstanding

[leafpetersen]

cc @munificent

@MichaelRFairhurst What's the status on this?

[MichaelRFairhurst]

Have been working on #30384 which has dragged on more than I expected. I should have either a fix for, or repro of, the DDC issue in a few days (hopefully, some point this weekend)

[MichaelRFairhurst]

The DDC issue here seems to be the original issue which prompted this. It merely reared its head at different times, and internally, required a patch to dart_lang in addition to third_party/ analyzer.

It seems from my tests that this is now working perfectly. Will keep straining the system a bit longer to increase my certainty in this.

[MichaelRFairhurst]

Glad I ran further tests.

Found yet another issue related to type parameters. Haven't yet distilled the error I'm seeing, but I'm getting A value of type 'OpaqueToken<T>' can't be assigned to a variable of type 'OpaqueToken<String>' in something like the following case:

// a.dart:
const x = OpaqueToken<String>(...);

// b.dart:
import 'a.dart' as a;
const x = a.x; // assignment error here!

Which is very, very strange. Working to distill this now.

[matanlurey]

Thanks!

[MichaelRFairhurst]

OK, digging further, that was a false alarm.

I am now extremely confident that this will work -- assuming you use --preview-dart-2 of course!

Edit: s/not/now