das: Extract CorrectionUtils.getTypeSource; tidy ExtractMethodRefactoring

This is mostly a very tidy extraction of `getTypeSource`. This method
relied on a handful of helper functions, all of which were _only_
present in order to help `getTypeSource`. This method also does not
rely on `_buffer` or `eol`. And it is only used by one piece of code,
`extract_method`. Almost a slam dunk!

However, there appeared some strange caveats that I must document
here:

CorrectionUtils also featured two mutable fields, `targetClassElement`
and `targetExecutableElement`. Theoretically, these fields are
supposed to be set before calling `getTypeSource`, to help understand
whether a TypeParameter will be visible when extracting a method, or
something like that. But it appears to be totally broken:

* The singular caller of `getTypeSource`, `ExtractMethodRefactoring`,
  _never sets those fields_.
* Two other pieces of code, the AddTypeAnnotation fix, and the
  CreateField, CreateFunction, and CreateOverrides fixes, all set the
  fields, but _never call getTypeSource_.

Since this all looked like just very stale / rotten code, I removed
everything which looks to be dead: `targetClassElement` and
`targetExecutableElement`, and lo and behold: no tests fail! I've kept
those things deleted, and added a TODO for TypeParameters.

Lastly, since I was trying to figure out ExtractMethodRefactoring, I
tidied it up:

* Make it final
* Rename `ERROR_EXITS` to `errorExits`
* Privatize `searchEngine`, `resolveResult`, `selectionOffset`,
  `selectionLength`, `librariesToImport`, and `variableType`.
* Both `selectionRange` and `utils` could be final as they were set
  in the constructor body, so move that to initializers, make final,
  and make private.

Change-Id: Ia3fb948e5424971eb4250e711c179707552ad8aa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/358663
Commit-Queue: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
7 files changed
tree: 4bb0f692943277d5f50fc22d9603b3f65b7b66eb
  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

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.