commit 872ef163f136a80138c213146500f1af7ca365b9
author Paul Berry <paulberry@google.com> Wed Jan 24 22:23:09 2024 +0000
committer Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> Wed Jan 24 22:23:09 2024 +0000
tree 4c62d0d1da88141fa8b29d54bef2c4643f7abec3
parent 8edbcacfb07aa2d7f5fbb289b724515b300de047

Fix missing analyzer error when pattern for-in iterable is nullable.

This was a mistake in the shared logic implementation during the
implementation of patterns; instead of verifying that the for-in
expression is a subtype of `Iterable<dynamic>` (or `Stream<dynamic>`
in the case of an `await for`), it merely verifies that it's a subtype
of `Iterable<dynamic>?` (or `Stream<dynamic>?`). At some point, the
requisite error checking was added to the front end, but not to the
analyzer.

In an ideal world, the solution would be to remove the error check
from the front end and add it to the shared logic; however, doing so
is not easy, because what needs to be done is an assignability check
(as well as insertion of implicit downcasts and other coercions). The
shared logic doesn't currently have a good hook for doing that. So,
for now, this CL simply adds the requisite check to the analyzer. I
plan to try to find a clean way to share some of this logic in a
follow-up CL.

Fixes https://github.com/dart-lang/sdk/issues/54671.

Change-Id: Ib2fa8bce758dfe12401d85850666674ca1317e3f
Bug: https://github.com/dart-lang/sdk/issues/54671
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/347360
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Samuel Rawlins <srawlins@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>