Add test about "T derives the future type U"

Issue https://github.com/dart-lang/sdk/issues/54628 raised the issue
that the static analysis of `await e` behaves in unexpected ways when
the static type of `e` is a subtype of a future related type, rather
than just a plain `Future<T>` or `FutureOr<T>` for some `T`.

This CL adds a test that assumes the update to the language
specification which is performed by the PR
https://github.com/dart-lang/language/pull/3574. Hence, this CL
should ONLY BE LANDED if and when that PR is landed.

Change-Id: Ib8acb77e24ffbceb0b4034d3b23a0f4fef8e3d1c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/354020
Reviewed-by: Lasse Nielsen <lrn@google.com>
Commit-Queue: Erik Ernst <eernst@google.com>
1 file changed
tree: adcfae6ea07e5277a0705c85514d3cb9f0b3b5f1
  1. .dart_tool/
  2. .github/
  3. benchmarks/
  4. build/
  5. docs/
  6. pkg/
  7. runtime/
  8. samples/
  9. sdk/
  10. tests/
  11. third_party/
  12. tools/
  13. utils/
  14. .clang-format
  15. .gitattributes
  16. .gitconfig
  17. .gitignore
  18. .gn
  19. .mailmap
  20. .style.yapf
  21. AUTHORS
  22. BUILD.gn
  23. CHANGELOG.md
  24. codereview.settings
  25. CONTRIBUTING.md
  26. DEPS
  27. LICENSE
  28. OWNERS
  29. PATENT_GRANT
  30. PRESUBMIT.py
  31. README.dart-sdk
  32. README.md
  33. sdk.code-workspace
  34. sdk_args.gni
  35. SECURITY.md
  36. WATCHLISTS
README.md

Dart

An approachable, portable, and productive language for high-quality apps on any platform

Dart is:

  • Approachable: Develop with a strongly typed programming language that is consistent, concise, and offers modern language features like null safety and patterns.

  • Portable: Compile to ARM, x64, or RISC-V machine code for mobile, desktop, and backend. Compile to JavaScript or WebAssembly for the web.

  • Productive: Make changes iteratively: use hot reload to see the result instantly in your running app. Diagnose app issues using DevTools.

Dart's flexible compiler technology lets you run Dart code in different ways, depending on your target platform and goals:

  • Dart Native: For programs targeting devices (mobile, desktop, server, and more), Dart Native includes both a Dart VM with JIT (just-in-time) compilation and an AOT (ahead-of-time) compiler for producing machine code.

  • Dart Web: For programs targeting the web, Dart Web includes both a development time compiler (dartdevc) and a production time compiler (dart2js).

Dart platforms illustration

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See LICENSE and PATENT_GRANT.

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