Stop the throwing-read poll test from failing on a busy machine

[kblok]

The test Keeps_polling_through_a_throwing_read_and_reports_its_error_at_the_deadline failed now and then in CI. Its read awaited Task.Yield() before it threw. When the thread pool was busy, the stepping clock moved on before that continuation ran. The read's own timeout fired first, and the poll said "no read completed" instead of showing the read's error. The read now fails at once, like upstream's async throw, so the test no longer depends on thread timing. The product code is correct. Accepts_an_asynchronous_read in the same file also awaits Task.Yield() under the stepping clock and can flake the same way. I left it alone here.

🤖 Generated with Claude Code

https://claude.ai/code/session_01KWUdrjfarTEM4dmBbK6GaV

Summary by CodeRabbit

• Tests
  • Updated automated coverage for repeated polling failures to check an asynchronous operation that is already faulted. This clarifies the failure scenario being tested and helps ensure the tests accurately verify polling behavior. No user-facing product behavior changed.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: Repository UI
• Review profile: CHILL
• Plan: Advanced
• Run ID: 73075300-aaac-4596-ac83-eb5bd6c10b42

📥 Commits

Reviewing files that changed from the base of the PR and between 895cd89 and cc94005.

📒 Files selected for processing: 1

• tests/E2E.Tests/ExpectPoll/ExpectPollTests.cs

Included review availability: This review used your included allowance. Your plan provides up to 10 included reviews per hour; 8 remain after this review.

📝 Walkthrough

The poll failure test now returns an already-faulted task from its read operation. A comment explains the setup and its interaction with the stepping clock.

Changes: Poll failure test

Layer / File(s)	Summary
Faulted read setup tests/E2E.Tests/ExpectPoll/ExpectPollTests.cs	The read operation returns a faulted task containing the same InvalidOperationException. A comment documents the setup and warns against awaiting before returning the task.

Priority: ⬇️ Low

Estimated code review effort: 1 (Trivial) | ~5 minutes

Change: Other

Merge Risk: ⚪ Minimal · up to cc940

The change removes the yield from the targeted deadline test while preserving its failure assertions. No actionable merge risk introduced by this change was established.

Pre-merge checks: 4 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 1 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

Passed checks: 4 passed

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly and concisely describes the main change: preventing the throwing-read poll test from failing because of busy-machine timing.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

• Fix all pre-merge checks with AI

✨ Finishing Touches: 💡 1

📝 Generate docstrings: 💡

• Commit to this branch
• Create a new PR

🧪 Generate unit tests (beta)

• Commit to this branch
• Create a new PR

• Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

_{Comment @coderabbitai help to get the list of available commands.}