commit b0e488fcb25db14b5586c5093e00e427e7a54f9d
author Paul Berry <paulberry@google.com> Tue Jun 03 17:10:44 2025 -0700
committer Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue Jun 03 17:10:44 2025 -0700
tree b81a5f60040e4dc20b94b97d2f34df5c76ef4831
parent cfccc2a2a845c71594f335c2f3da0cf5c0a20fa1

[flow analysis] In tests, stop rewriting ordinary variable declarations.

During the implementation of flow analysis for patterns, I added a
hack to the flow analysis tests so that all variable declarations were
desugared into the equivalent pattern variable declaration. This had
the advantage of getting some extra testing "for free" during early
development of the patterns feature, but it had a few disadvantages:

- It the caused the shared flow analysis and type inference tests to
  stop exercising flow analysis code paths for ordinary variable
  declarations.

- It forced the testing logic to "support" pattern variable
  declarations that are late or lack an initializer; these are things
  that regular Dart doesn't support, and they made the implementation
  of `PatternVariableDeclaration.visit` much more complicated than it
  needed to be.

The language team is currently contemplating some changes to how
promotions work in ordinary variable declarations and pattern variable
declarations (see, for example,
https://github.com/dart-lang/language/issues/4347#issuecomment-2861859329). So
in order to be able to experiment with these possibilities, I want to
get rid of this hack.

This CL adds a `VariableDeclaration` class, to represent ordinary
variable declarations, and modifies the `declare` function (which is
used by tests for creating an ordinary variable declaration) so that
it creates a `VariableDeclaration`, rather than rewriting it into a
`PatternVariableDeclaration` containing a `VariablePattern`. It
removes "support" for testing pattern variable declarations that are
late or lack an initializer, simplifying
`PatternVariableDeclaration.visit`.

A few test cases in `type_inference_test.dart` were checking the
generated IR for ordinary variable declarations, verifying that it was
properly desugared into a pattern variable declaration; these
expectations have accordingly changed to no longer expect desugaring.

There is no functional change to the compiler or analyzer
toolchain. These changes only affect tests in
`pkg/_fe_analyzer_shared/test`.

Change-Id: I90f074cd6e7a6ed5ed11afadeadb6131ce1d282f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/432122
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>