Adds assist for basic Flutter Builder

Fixes issues such as

* https://github.com/flutter/flutter-intellij/issues/814
* https://github.com/dart-lang/sdk/issues/33957 .

Essentially, in Flutter, it's often useful to create a new context in the UI/widget tree as a place to begin a search towards the trunk of the tree for various state structures attached to lower levels of the tree. The basic `Builder` widget is the official means for creating such a context/entry-point.

The patches in this PR are essentially a copy-paste-tweak from two types of existing, similar assists. The main origin was taken from `FlutterWrapStreamBuilder` which wraps client code with a constructor for the StreamBuilder sub-class. The new assist, provided here, is a little more basic/general than the StreamBuilder so it was able to also adopt assertion and test code from some of the other assists for basic widgets.

Closes https://github.com/dart-lang/sdk/pull/45656
https://github.com/dart-lang/sdk/pull/45656

GitOrigin-RevId: 00a5043e5dbd410f24f30f6503711413341dbe7a
Change-Id: I5f93837af571b4974e35da131112f82cd9359697
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/194941
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>
7 files changed
tree: 1c0113562ff6995b659c2b489935fb25de73977b
  1. .dart_tool/
  2. .github/
  3. benchmarks/
  4. build/
  5. client/
  6. docs/
  7. pkg/
  8. runtime/
  9. samples/
  10. samples-dev/
  11. samples_2/
  12. sdk/
  13. tests/
  14. third_party/
  15. tools/
  16. utils/
  17. .clang-format
  18. .gitattributes
  19. .gitconfig
  20. .gitignore
  21. .gn
  22. .mailmap
  23. .packages
  24. .style.yapf
  25. .vpython
  26. AUTHORS
  27. BUILD.gn
  28. CHANGELOG.md
  29. codereview.settings
  30. CONTRIBUTING.md
  31. DEPS
  32. LICENSE
  33. PATENT_GRANT
  34. PRESUBMIT.py
  35. README.dart-sdk
  36. README.md
  37. sdk_args.gni
  38. WATCHLISTS
README.md

Dart

A client-optimized language for fast apps on any platform

Dart is:

  • Optimized for UI: Develop with a programming language specialized around the needs of user interface creation.

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

  • Fast on all platforms: Compile to ARM & x64 machine code for mobile, desktop, and backend. Or compile to JavaScript for the web.

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

License & patents

Dart is free and open source.

See LICENSE and PATENT_GRANT.

Using Dart

Visit dart.dev to learn more about the language, tools, and to find codelabs.

Browse pub.dev for more packages and libraries contributed by the community and the Dart team.

Our API reference documentation is published at api.dart.dev, based on the stable release. (We also publish docs from our beta and dev channels, as well as from the primary development branch).

Building Dart

If you want to build Dart yourself, here is a guide to getting the source, preparing your machine to build the SDK, and building.

There are more documents on our wiki.

Contributing to Dart

The easiest way to contribute to Dart is to file issues.

You can also contribute patches, as described in Contributing.