Analyzer: phantom analyze issue for enums

[khobotin-elopage]

The issue appeared after upgrading to Dart 2.17 & Flutter 3

STR:
Create new flutter project and write:

enum MyEnum {
  myValue(type: TextInputType.none);

  const MyEnum({this.type = TextInputType.text});

  final TextInputType type;
}

the code {this.type = TextInputType.text} throws an error The default value of an optional parameter must be constant.

But TextInputType.text is a constant value

static const TextInputType text = TextInputType._(0);

if I run dart analyze I will get

error • lib/main.dart:120:29 • The default value of an optional parameter must be constant. • non_constant_default_value

The most strange part starts when I go to TextInputType.text definition and then back, or just change a file (delete symbol in text and then undo action), the error dissapears. And now dart analyze show

No issues found!

But once I run command Restart Analysis Server, it go back.

It only applicable for enums. This code

class ClassA {
  const ClassA({this.type = TextInputType.text});

  final TextInputType type;
}

doesn't show any errors.

Another strange thing is: if I put together enum and class and set the same TextInputType default value, enum will not show the error (even after analyzer restart). Like this:

enum MyEnum {
  myValue(type: TextInputType.none);

  const MyEnum({this.type = TextInputType.text});

  final TextInputType type;
}

class ClassA {
  const ClassA({this.type = TextInputType.text});

  final TextInputType type;
}

But once I set TextInputType default value for enum other than text, and restart analyzer, error goes back.

Dart SDK version: 2.17.0 (stable) on macos_arm64
Flutter 3.0.1 • channel stable
IDE: VS Code

[scheglov]

I can reproduce it:

  solo_test_XXX() async {
    newFile('$testPackageLibPath/a.dart', r'''
class TextInputType {
  static const none = TextInputType(-1);
  static const text = TextInputType(0);

  final int value;
  const TextInputType(this.value);
}
''');
    await assertNoErrorsInCode(r'''
import 'a.dart';

enum MyEnum {
  myValue(type: TextInputType.none);

  const MyEnum({this.type = TextInputType.text});

  final TextInputType type;
}
''');
  }

Produces:

  Found but did not expect:
    CompileTimeErrorCode.NON_CONSTANT_DEFAULT_VALUE [98, 18, "The default value of an optional parameter must be constant.", null]
  
  To accept the current state, expect:
    error(CompileTimeErrorCode.NON_CONSTANT_DEFAULT_VALUE, 98, 18),

[scheglov]

https://dart-review.googlesource.com/c/sdk/+/245909

[scheglov]

I requested a cherry pick for this fix.

[khobotin-elopage]

Thanks a lot for quick fix, @scheglov ! ❤️