Suggestion: add @optionalTypeArgs to MapEntry

[nate-thegrate]

Pattern-matching with MapEntry is very satisfying, but when always_specify_types is on, it's kinda awful.

final List<String> list = <String>[
  for (final MapEntry<KeyClass, ValueClassWithAVeryLongName>(:KeyClass key, :ValueClassWithAVeryLongName value) in map.entries)
    '$key, $value',
];

I'd much prefer not needing to add the type parameters here:

final List<String> list = <String>[
  for (final MapEntry(:KeyClass key, :ValueClassWithAVeryLongName value) in map.entries)
    '$key, $value',
];

[lrhn]

I think the lint is probably working as intended.

Requiring a type annotation for var x = 10;, where the inferred type is obvious, means that the lint really intends all types to be written, even if they are inferred.

I don't know if it's the same lint that requires the the type parameters to MapEntry. I'd have assumed that

   for (final MapEntry(:KeyClass key, :ValueClassWithAVeryLongName value)  ...

would be enough, since this lint is about the variable declarations. (And MapEntry is not a raw type here, so should not be affected by strict_raw_types.)

[nate-thegrate]

It looks like the always_specify_type lint kicks in when you don't add the MapEntry type parameters. (I'll update the original comment for clarity.)