Roll engine to f3ff83a5db71262d240aa5337a2a9a22c73c4749. (dart roll).

[aam]

No description provided.

[aam]

https://dart-review.googlesource.com/c/sdk/+/70160 (cc @jcollins-g ) caused analyzer warnings reported in https://github.com/flutter/flutter/runs/14496912:

   info • Prefer declare const constructors on `@immutable` classes • packages/flutter/lib/src/widgets/platform_view.dart:53:3 • prefer_const_constructors_in_immutables
   info • Prefer declare const constructors on `@immutable` classes • packages/flutter/lib/src/widgets/scroll_view.dart:53:3 • prefer_const_constructors_in_immutables
   info • Prefer declare const constructors on `@immutable` classes • packages/flutter/lib/src/widgets/single_child_scroll_view.dart:186:3 • prefer_const_constructors_in_immutables

Those were incorrect lints which required adding appropriate //ignore directives.

[devoncarew]

@danrubel, looks like an issue related to the move to Fasta. Also cc'ing @a14n, who authored the lint.

From the docs here: http://dart-lang.github.io/linter/lints/prefer_const_constructors_in_immutables.html, it looks like we need an @immutable annotation on the definition of the class in order for this lint to apply. I don't see that annotation on these classes, so I'm not sure why the lint would be firing.

[devoncarew]

I filed dart-lang/sdk#34297 to track this.

[a14n]

I don't see that annotation on these classes, so I'm not sure why the lint would be firing.

@immutable applies to child classes. Widget (which is a parent of AndroidView) is annotated with @immutable.

[devoncarew]

It looks like the lint is correct then, and we should change the constructors over to const?

[aam]

It looks like the lint is correct then, and we should change the constructors over to const?

It doesn't work as there are other constraints that prevent those constructors to be const.

[devoncarew]

OK, sounds like there are false positives with the lint, or issues where we don't actually want the constructor to be const even for immutable classes.

[a14n]

It doesn't work as there are other constraints that prevent those constructors to be const.

Once dart-lang/sdk#33408 has landed all constructors pointed out in the log could be const. I think we are in a transition state where CFE and Analyzer differ. /cc @bwilkerson

[a14n]

For instance:

  AndroidView({ // ignore: prefer_const_constructors_in_immutables
    Key key,
    @required this.viewType,
    this.onPlatformViewCreated,
    this.hitTestBehavior = PlatformViewHitTestBehavior.opaque,
    this.layoutDirection,
    this.gestureRecognizers = const <OneSequenceGestureRecognizer> [],
    this.creationParams,
    this.creationParamsCodec
  }) : assert(viewType != null),
       assert(hitTestBehavior != null),
       assert(gestureRecognizers != null),
       assert(creationParams == null || creationParamsCodec != null),
       super(key: key);

creationParams == null prevents const for now but will be const after the landing of dart-lang/sdk#33408

[aam]

Thank you, @a14n . Makes sense.