test: fix flaky ObjectInitializer continuation-thread test

[thomhurst]

Summary

ObjectInitializerTests.Waiting_Continuations_Do_Not_Run_On_The_Initializing_Thread failed on macOS CI (run 36556399225) with Expected to not be equal to 17.

Cause: the test runs initialization on a TaskCreationOptions.LongRunning dedicated thread, which exits as soon as initialization finishes. It then compared Environment.CurrentManagedThreadId values. The runtime can give a dead thread's managed ID to a new thread-pool thread, and that thread can run a correctly queued waiter continuation. The IDs then match even though the product code behaved correctly.

Fix: capture Thread.CurrentThread and assert IsNotSameReferenceAs. A new thread-pool thread is always a different Thread object, even when it gets the same ID. The assertion still checks the same behaviour.

Test plan

• Ran the test (both arguments) 25 times in a row on net10.0 Release: 25/25 passed.
• The whole ObjectInitializerTests class passes: 11/11.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Tests
  • Improved validation that waiter continuations run on a different thread from the one performing initialization.

[chatgpt-codex-connector]

Codex Review Summary

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-29T14:23:23.980127Z	86a7b33	PR opened

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Advanced

Run ID: 2c6e858c-d25c-4150-85d2-a341e65a501a

📥 Commits

Reviewing files that changed from the base of the PR and between c496882 and 86a7b33.

📒 Files selected for processing (1)

• tests/TUnit.UnitTests/ObjectInitializerTests.cs

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📝 Walkthrough

Walkthrough

The object initializer test now tracks the initializing thread and waiter continuation threads as Thread objects. It asserts that the initializing thread is non-null and that each waiter continuation runs on a different thread object.

Changes

Object initializer thread test

Layer / File(s)	Summary
Thread identity assertions tests/TUnit.UnitTests/ObjectInitializerTests.cs	The test records the initializing thread and waiter continuation threads as Thread objects. It checks that the initializing thread is non-null and compares thread references.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~7 minutes

Change: Other

Suggested reviewers: sing303

Merge Risk: ⚪ Minimal · up to 86a7b

This test-only change avoids false failures from reused thread IDs while preserving the regression scenario. No actionable merge risk remains.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	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	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly identifies the flaky ObjectInitializer continuation-thread test and the corrective change. It is concise and directly related to the main purpose of the pull request.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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_{A rabbit checks each thread with care,
The initializing thread is there.
Waiters take a different track,
No managed IDs to compare back.
The test now watches objects hop,
Then marks its tidy check complete.}

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

[github-actions]

Review: LGTM.

The diagnosis is sound. ManagedThreadId can be recycled after the LongRunning thread exits, so comparing Thread references is the right fix. It keeps the same intent, because a distinct live or dead Thread object is never the same reference. The added IsNotNull guard on initializingThread is a good touch: without it, a null would make IsNotSameReferenceAs pass vacuously against a never-assigned value.

Minor, non-blocking: holding the Thread reference keeps the exited thread object alive until the test ends. That is harmless here.

No issues found.

[greptile-apps]

Confidence Score: 5/5

[Low risk]

The PR appears safe to merge.

Summary

The PR changes a test to compare Thread objects rather than managed thread IDs, avoiding a false failure when a dedicated thread’s ID is reused.

• The assertion API and initializer lifecycle support the revised check.

_{Reviews (1) · Last reviewed commit: "test: compare Thread identity in ObjectI..."}