Description

This PR adds a stackTrace member that allows to trace errors in StreamBuilder and FutureBuilder. Previously, errors were not tracable in said widgets.

The stackTrace member is always specified when the error member is also specified.

Non-breaking

The stackTrace is a new optional parameter for AsyncSnapshot.withError; if not specified, StackTrace.empty will be used, which aligns with what stream controllers, completers, etc. do.

Related Issues

• Resolves #53384.

Tests

I added the following tests:

• New tests specific to AsyncSnapshot.stackTrace in async_test.dart.
• Updated existing tasks to reflect the onString changes in the same file.

Checklist

Before you create this PR, confirm that it meets all requirements listed below by checking the relevant checkboxes ([x]). This will ensure a smooth and quick review process.

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I signed the CLA.
• I read and followed the Flutter Style Guide, including Features we expect every widget to implement.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I updated/added relevant documentation (doc comments with ///).
• All existing and new tests are passing.
• The analyzer (flutter analyze --flutter-repo) does not report any problems on my PR.
• I am willing to follow-up on review comments in a timely manner.

Breaking Change

Did any tests fail when you ran them? Please read Handling breaking changes.

• Nes, some existing tests failed, however, only because they depended on the toString method of AsyncSnapshot. User code should realistically not depend on toString because the class provides the members publicly.