Add more common strong-mode issues

[matanlurey]

Page: https://dart.dev/guides/language/sound-problems https://github.com/dart-lang/site-www/blob/master/src/_guides/language/sound-problems.md

I'd love to see two more items here, and I'm happy to help send/edit:

• [x] uses_dynamic_as_bottom (contravariant function type parameters, etc)
• [x] Invalid type casts (JSArray is not List<String>)
• [ ] type parameter conflicts
• [ ] callable classes

/cc @leafpetersen @lrhn @srawlins @munificent

[kwalrath]

If you could do a quick first pass (even just pointing to before and after examples, along with any other text you can easily put together), I'd be happy to finish it and publish it.

[matanlurey]

From @leafpetersen, two more issues we should highlight:

Type parameter conflicts:

• A class may not implement (even transitively, anywhere in its superclass hierarchy) the same generic interface with different type parameters.
• So no having List<int> and List<double> in your class hierarchy somewhere.
• You can have the same generic interface with the same type parameters

Callable classes:

• A class with a call method can still be "called" using the call syntax: o(arguments)
• A function can still be called with the ".call" syntax
• But if
  • you use an object o with static type C
  • where C has a call method
  • in a context where a function typed thing is expected
  • then this will be treated as a tearoff of the call method, instead of just passing the object directly

There's a good comment on this bug: https://github.com/dart-lang/sdk/issues/32151

with concrete examples of how Dart 2 will differ from Dart 1

[srawlins]

I think GitHub Markdown ate your generics on List and List.

[chalin]

I think GitHub Markdown ate your generics on List and List.

Fixed.