Complex nested cascades sometimes extend past line length unnecessarily

[cpelling]

The following code is formatted by dartfmt as shown. Note that the last line of actual code is longer than 80 characters.

void main() async {
  group('my group', () {
    setUp(() async {
      final requestHandler = FakeRequestHandler()
        ..when(withServiceName(Ng2ProtoFooBarBazService.serviceName))
            .thenRespond(FooBarBazListResponse()
              ..entities.add(FooBarBaz()
                ..fooBarBazEntityId = entityId
                ..name = 'Test entity'
                ..baseFooBarBazId = baseFooBarBazId
                ..entityFooBarBazId = entityFooBarBazId))
        ..when(allOf(withServiceName(Ng2ProtoFooBarBazService.serviceName),
                hasFooBarBazId(baseFooBarBazId)))
            .thenRespond(FooBarBazListResponse()..entities.add(baseFooBarBaz))
        ..when(allOf(withServiceName(Ng2ProtoFooBarBazService.serviceName),
                hasFooBarBazId(entityFooBarBazId)))
            .thenRespond(FooBarBazListResponse()..entities.add(entityFooBarBaz))
        ..when(allOf(withServiceName(Ng2ProtoFooBarBazService.serviceName),
                hasFooBarBazIds(Set.from([baseFooBarBazId, entityFooBarBazId]))))
            .thenRespond(
                FooBarBazListResponse()..entities.addAll([baseFooBarBaz, entityFooBarBaz]));
    });
  });
}

The output I'd expect is more like:

void main() async {
  group('my group', () {
    setUp(() async {
      final requestHandler = FakeRequestHandler()
        ..when(withServiceName(Ng2ProtoFooBarBazService.serviceName))
            .thenRespond(FooBarBazListResponse()
              ..entities.add(FooBarBaz()
                ..fooBarBazEntityId = entityId
                ..name = 'Test entity'
                ..baseFooBarBazId = baseFooBarBazId
                ..entityFooBarBazId = entityFooBarBazId))
        ..when(allOf(withServiceName(Ng2ProtoFooBarBazService.serviceName),
                hasFooBarBazId(baseFooBarBazId)))
            .thenRespond(FooBarBazListResponse()..entities.add(baseFooBarBaz))
        ..when(allOf(withServiceName(Ng2ProtoFooBarBazService.serviceName),
                hasFooBarBazId(entityFooBarBazId)))
            .thenRespond(FooBarBazListResponse()..entities.add(entityFooBarBaz))
        ..when(allOf(withServiceName(Ng2ProtoFooBarBazService.serviceName),
                hasFooBarBazIds(Set.from([baseFooBarBazId, entityFooBarBazId]))))
            .thenRespond(FooBarBazListResponse()
              ..entities.addAll([baseFooBarBaz, entityFooBarBaz]));
    });
  });
}

In other words, I'd expect the final when().thenRespond() chain to wrap more like the first one does.

There's some interesting interactions going on within this expression which are hard to figure out from a black-box perspective. Simplifying the above code any more than this (for example, removing any of the when() calls) fixes the issue.

[natebosch]

https://github.com/dart-lang/dart_style/wiki/FAQ#why-did-the-formatter-only-format-some-of-my-code

You might want to break this up into multiple expressions.

[munificent]

I'm going to keep this open so we can use it as a regression test if we optimize how cascades are formatted.

[munificent]

Here's another (sanitized) example:

aaaa() {
  {
    {
      {
        aaaaa aaaaa = AaaAaaaa.aaaaaaa().aaaaaaa((a) => a
          ..aaaaAaaaa
                  .aaaaaaaaaaaAaAaaa[AaaaAaaaaaaaaaAaaa_Aaaa.AAA_AAAAAAAAAAA_AAAAA_AAAAAAA.aaaa] =
              aaaa
          ..aaaaAaaaa.aaaaaaaaaaaAaAaaa[AaaaAaaaaaaaaaAaaa_Aaaa
              .AAA_AAAAAAAAAAA_AAAAAAAA_AAAA_AAAAAAAAA.aaaa] = aaaa
          ..aaaaAaaaa.aaaaaaaaaaaAaAaaa[AaaaAaaaaaaaaaAaaa_Aaaa
              .AAA_AAAAAAAAAAA_AAAAAAA_AAAA_AAAAAAAAA.aaaa] = aaaa
          ..aaaaAaaaa.aaaaaaaaaaaAaAaaa[AaaaAaaaaaaaaaAaaa_Aaaa
              .AAA_AAAAAAAAAAA_AAAAAA_AAAAAAA_AAA_AAAAAAAAAAA_AAAAA.aaaa] = aaaa
          ..aaaaaaaaAaaaaaAaaaa.aaaaaaa(AaaaaaaaAaaaaaAaaaaAaaaa.aaaaaaa())
          ..aaaaaaaaAaaaa.aaaaaaaa =
              (Aaaaaaaa()..aaaaaaaaAaaa = (AaaaaaaaAaaa()..aaAaaaaaa = aaaaa)));
      }
    }
  }
}