Inconsistent spacing when an initializer list is used with required arguments

[jamesderlin]

To reproduce, run dart format on:

class Foo {
  Foo({
    required int x,
  })  : assert(x != 0),
        assert(x != -1);
}

The result is:

class Foo {
  Foo({
    required int x,
  })   : assert(x != 0),
        assert(x != -1);
}

There are now three spaces instead of the usual two in front of the :, disrupting the alignment of the rest of the initializer list. This only seems to happen if:

• There are multiple elements to the initializer list. If there's only one, there will be only a single space before the :.
• The last construction parameter is required.
• The construction parameters have a trailing comma.

What the initializer list members are doesn't seem to matter; they can be asserts, actual initializers, or calls to super().

I can reproduce this with DartPad (which as of writing, is based on Flutter 2.0.3 Dart SDK 2.12.2).