Harden acceptance test timing assertions

[Amaury Levé (Evangelink)]

Hardcoded wall-clock ceilings made acceptance tests susceptible to loaded CI agents, while one attribute-precedence check raced against the exact configured timeout with no margin.

• Replace raw numeric ceilings with named TimeSpan limits and document their CI allowance.
• Record a monotonic timestamp in the generated child at finalization or disposal entry, so the parent measures only cleanup and teardown without process-startup overhead, polling, or observation races.
• Remove the redundant stopwatch assertion where the reported 1000ms timeout already proves attribute precedence.
• Add contributor guidance for process-level timing assertions.

Validation: packed the repository and ran the affected MTP and MSTest acceptance classes, including the revised lifetime-handler tests across all targeted frameworks.

Fixes#10899

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

What changed in this PR

Hardens acceptance-test timing checks against slow CI agents while preserving regression detection.

Changes:

• Replaces tight numeric ceilings with documented 30-second limits.
• Extends blocking fixtures and removes a redundant timing assertion.
• Adds contributor guidance for process-level timing checks.

File	Description
.github/​copilot-instructions.md	Documents robust timing-assertion practices.
DataConsumerThroughputTests.cs	Adds a CI-tolerant throughput limit.
TestHostProcessLifetimeHandlerTests.cs	Relaxes timing limits and extends blocking operations.
TimeoutWhenExpiresTests.cs	Removes the redundant stopwatch assertion.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight…

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight… View resolved comment

Suppressed comments (2)

Previously missed (1) — in code that hasn't changed since the last review.

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:71

• This still has an observation race: the child writes finalizationStartedFile immediately before entering its 10-second sleep, but the stopwatch starts only when the parent is scheduled and notices that file. If the parent is delayed, some or all of the blocking interval is omitted, so a broken finalization timeout can satisfy the five-second assertion. Use a two-way rendezvous: have the child publish a ready marker and wait for a release marker, then start the stopwatch before releasing it into the blocking callback.

This issue also appears on line 103 of the same file.

 await WaitForFileAsync(finalizationStartedFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:105

• The same observation race exists for disposal: the child appends the attempt marker and immediately begins its 10-second sleep, while this stopwatch starts only after the parent polling loop runs. Parent scheduling delay therefore gets subtracted from the measured disposal time and can let a regressed timeout pass. Add a child-to-parent ready marker plus a parent-to-child release marker, starting the stopwatch before releasing disposal to block.

 await WaitForFileAsync(disposalAttemptsFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

[Amaury Levé (Evangelink)]

Addressed the two suppressed observation-race findings from the latest Copilot review in 8a0b77ed4. The generated test host now reports readiness before the timeout path begins and waits for the parent to release it; the parent starts timing before that release, so process startup and scheduling delays are excluded without omitting any of the blocking interval.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the…

Suppressed comments (1)

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:115

• This stopwatch also starts at execution release rather than after Dispose begins (the disposal-attempt marker is written at callback entry). Consequently, the test does not implement the callback-scoped timing described by the PR and includes timeout/pre-disposal work. Either wait for disposalAttemptsFile before starting timing, or revise the PR description to state the actual scope.

 var stopwatch = Stopwatch.StartNew();

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the… View resolved comment

[Amaury Levé (Evangelink)]

Hardcoded wall-clock ceilings made acceptance tests susceptible to loaded CI agents, while one attribute-precedence check raced against the exact configured timeout with no margin.

• Replace raw numeric ceilings with named TimeSpan limits and document their CI allowance.
• Record a monotonic timestamp in the generated child at finalization or disposal entry, so the parent measures only cleanup and teardown without process-startup overhead, polling, or observation races.
• Remove the redundant stopwatch assertion where the reported 1000ms timeout already proves attribute precedence.
• Add contributor guidance for process-level timing assertions.

Validation: packed the repository and ran the affected MTP and MSTest acceptance classes, including the revised lifetime-handler tests across all targeted frameworks.

Fixes#10899

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

What changed in this PR

Hardens acceptance-test timing checks against slow CI agents while preserving regression detection.

Changes:

• Replaces tight numeric ceilings with documented 30-second limits.
• Extends blocking fixtures and removes a redundant timing assertion.
• Adds contributor guidance for process-level timing checks.

File	Description
.github/​copilot-instructions.md	Documents robust timing-assertion practices.
DataConsumerThroughputTests.cs	Adds a CI-tolerant throughput limit.
TestHostProcessLifetimeHandlerTests.cs	Relaxes timing limits and extends blocking operations.
TimeoutWhenExpiresTests.cs	Removes the redundant stopwatch assertion.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight…

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight… View resolved comment

Suppressed comments (2)

Previously missed (1) — in code that hasn't changed since the last review.

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:71

• This still has an observation race: the child writes finalizationStartedFile immediately before entering its 10-second sleep, but the stopwatch starts only when the parent is scheduled and notices that file. If the parent is delayed, some or all of the blocking interval is omitted, so a broken finalization timeout can satisfy the five-second assertion. Use a two-way rendezvous: have the child publish a ready marker and wait for a release marker, then start the stopwatch before releasing it into the blocking callback.

This issue also appears on line 103 of the same file.

 await WaitForFileAsync(finalizationStartedFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:105

• The same observation race exists for disposal: the child appends the attempt marker and immediately begins its 10-second sleep, while this stopwatch starts only after the parent polling loop runs. Parent scheduling delay therefore gets subtracted from the measured disposal time and can let a regressed timeout pass. Add a child-to-parent ready marker plus a parent-to-child release marker, starting the stopwatch before releasing disposal to block.

 await WaitForFileAsync(disposalAttemptsFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

[Amaury Levé (Evangelink)]

Addressed the two suppressed observation-race findings from the latest Copilot review in 8a0b77ed4. The generated test host now reports readiness before the timeout path begins and waits for the parent to release it; the parent starts timing before that release, so process startup and scheduling delays are excluded without omitting any of the blocking interval.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the…

Suppressed comments (1)

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:115

• This stopwatch also starts at execution release rather than after Dispose begins (the disposal-attempt marker is written at callback entry). Consequently, the test does not implement the callback-scoped timing described by the PR and includes timeout/pre-disposal work. Either wait for disposalAttemptsFile before starting timing, or revise the PR description to state the actual scope.

 var stopwatch = Stopwatch.StartNew();

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the… View resolved comment

[Amaury Levé (Evangelink)]

Hardcoded wall-clock ceilings made acceptance tests susceptible to loaded CI agents, while one attribute-precedence check raced against the exact configured timeout with no margin.

• Replace raw numeric ceilings with named TimeSpan limits and document their CI allowance.
• Record a monotonic timestamp in the generated child at finalization or disposal entry, so the parent measures only cleanup and teardown without process-startup overhead, polling, or observation races.
• Remove the redundant stopwatch assertion where the reported 1000ms timeout already proves attribute precedence.
• Add contributor guidance for process-level timing assertions.

Validation: packed the repository and ran the affected MTP and MSTest acceptance classes, including the revised lifetime-handler tests across all targeted frameworks.

Fixes#10899

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

What changed in this PR

Hardens acceptance-test timing checks against slow CI agents while preserving regression detection.

Changes:

• Replaces tight numeric ceilings with documented 30-second limits.
• Extends blocking fixtures and removes a redundant timing assertion.
• Adds contributor guidance for process-level timing checks.

File	Description
.github/​copilot-instructions.md	Documents robust timing-assertion practices.
DataConsumerThroughputTests.cs	Adds a CI-tolerant throughput limit.
TestHostProcessLifetimeHandlerTests.cs	Relaxes timing limits and extends blocking operations.
TimeoutWhenExpiresTests.cs	Removes the redundant stopwatch assertion.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight…

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight… View resolved comment

Suppressed comments (2)

Previously missed (1) — in code that hasn't changed since the last review.

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:71

• This still has an observation race: the child writes finalizationStartedFile immediately before entering its 10-second sleep, but the stopwatch starts only when the parent is scheduled and notices that file. If the parent is delayed, some or all of the blocking interval is omitted, so a broken finalization timeout can satisfy the five-second assertion. Use a two-way rendezvous: have the child publish a ready marker and wait for a release marker, then start the stopwatch before releasing it into the blocking callback.

This issue also appears on line 103 of the same file.

 await WaitForFileAsync(finalizationStartedFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:105

• The same observation race exists for disposal: the child appends the attempt marker and immediately begins its 10-second sleep, while this stopwatch starts only after the parent polling loop runs. Parent scheduling delay therefore gets subtracted from the measured disposal time and can let a regressed timeout pass. Add a child-to-parent ready marker plus a parent-to-child release marker, starting the stopwatch before releasing disposal to block.

 await WaitForFileAsync(disposalAttemptsFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

[Amaury Levé (Evangelink)]

Addressed the two suppressed observation-race findings from the latest Copilot review in 8a0b77ed4. The generated test host now reports readiness before the timeout path begins and waits for the parent to release it; the parent starts timing before that release, so process startup and scheduling delays are excluded without omitting any of the blocking interval.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the…

Suppressed comments (1)

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:115

• This stopwatch also starts at execution release rather than after Dispose begins (the disposal-attempt marker is written at callback entry). Consequently, the test does not implement the callback-scoped timing described by the PR and includes timeout/pre-disposal work. Either wait for disposalAttemptsFile before starting timing, or revise the PR description to state the actual scope.

 var stopwatch = Stopwatch.StartNew();

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the… View resolved comment

[Amaury Levé (Evangelink)]

Hardcoded wall-clock ceilings made acceptance tests susceptible to loaded CI agents, while one attribute-precedence check raced against the exact configured timeout with no margin.

• Replace raw numeric ceilings with named TimeSpan limits and document their CI allowance.
• Record a monotonic timestamp in the generated child at finalization or disposal entry, so the parent measures only cleanup and teardown without process-startup overhead, polling, or observation races.
• Remove the redundant stopwatch assertion where the reported 1000ms timeout already proves attribute precedence.
• Add contributor guidance for process-level timing assertions.

Validation: packed the repository and ran the affected MTP and MSTest acceptance classes, including the revised lifetime-handler tests across all targeted frameworks.

Fixes#10899

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

What changed in this PR

Hardens acceptance-test timing checks against slow CI agents while preserving regression detection.

Changes:

• Replaces tight numeric ceilings with documented 30-second limits.
• Extends blocking fixtures and removes a redundant timing assertion.
• Adds contributor guidance for process-level timing checks.

File	Description
.github/​copilot-instructions.md	Documents robust timing-assertion practices.
DataConsumerThroughputTests.cs	Adds a CI-tolerant throughput limit.
TestHostProcessLifetimeHandlerTests.cs	Relaxes timing limits and extends blocking operations.
TimeoutWhenExpiresTests.cs	Removes the redundant stopwatch assertion.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight…

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight… View resolved comment

Suppressed comments (2)

Previously missed (1) — in code that hasn't changed since the last review.

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:71

• This still has an observation race: the child writes finalizationStartedFile immediately before entering its 10-second sleep, but the stopwatch starts only when the parent is scheduled and notices that file. If the parent is delayed, some or all of the blocking interval is omitted, so a broken finalization timeout can satisfy the five-second assertion. Use a two-way rendezvous: have the child publish a ready marker and wait for a release marker, then start the stopwatch before releasing it into the blocking callback.

This issue also appears on line 103 of the same file.

 await WaitForFileAsync(finalizationStartedFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:105

• The same observation race exists for disposal: the child appends the attempt marker and immediately begins its 10-second sleep, while this stopwatch starts only after the parent polling loop runs. Parent scheduling delay therefore gets subtracted from the measured disposal time and can let a regressed timeout pass. Add a child-to-parent ready marker plus a parent-to-child release marker, starting the stopwatch before releasing disposal to block.

 await WaitForFileAsync(disposalAttemptsFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

[Amaury Levé (Evangelink)]

Addressed the two suppressed observation-race findings from the latest Copilot review in 8a0b77ed4. The generated test host now reports readiness before the timeout path begins and waits for the parent to release it; the parent starts timing before that release, so process startup and scheduling delays are excluded without omitting any of the blocking interval.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the…

Suppressed comments (1)

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:115

• This stopwatch also starts at execution release rather than after Dispose begins (the disposal-attempt marker is written at callback entry). Consequently, the test does not implement the callback-scoped timing described by the PR and includes timeout/pre-disposal work. Either wait for disposalAttemptsFile before starting timing, or revise the PR description to state the actual scope.

 var stopwatch = Stopwatch.StartNew();

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the… View resolved comment

[Amaury Levé (Evangelink)]

Hardcoded wall-clock ceilings made acceptance tests susceptible to loaded CI agents, while one attribute-precedence check raced against the exact configured timeout with no margin.

• Replace raw numeric ceilings with named TimeSpan limits and document their CI allowance.
• Record a monotonic timestamp in the generated child at finalization or disposal entry, so the parent measures only cleanup and teardown without process-startup overhead, polling, or observation races.
• Remove the redundant stopwatch assertion where the reported 1000ms timeout already proves attribute precedence.
• Add contributor guidance for process-level timing assertions.

Validation: packed the repository and ran the affected MTP and MSTest acceptance classes, including the revised lifetime-handler tests across all targeted frameworks.

Fixes#10899

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

What changed in this PR

Hardens acceptance-test timing checks against slow CI agents while preserving regression detection.

Changes:

• Replaces tight numeric ceilings with documented 30-second limits.
• Extends blocking fixtures and removes a redundant timing assertion.
• Adds contributor guidance for process-level timing checks.

File	Description
.github/​copilot-instructions.md	Documents robust timing-assertion practices.
DataConsumerThroughputTests.cs	Adds a CI-tolerant throughput limit.
TestHostProcessLifetimeHandlerTests.cs	Relaxes timing limits and extends blocking operations.
TimeoutWhenExpiresTests.cs	Removes the redundant stopwatch assertion.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight…

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight… View resolved comment

Suppressed comments (2)

Previously missed (1) — in code that hasn't changed since the last review.

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:71

• This still has an observation race: the child writes finalizationStartedFile immediately before entering its 10-second sleep, but the stopwatch starts only when the parent is scheduled and notices that file. If the parent is delayed, some or all of the blocking interval is omitted, so a broken finalization timeout can satisfy the five-second assertion. Use a two-way rendezvous: have the child publish a ready marker and wait for a release marker, then start the stopwatch before releasing it into the blocking callback.

This issue also appears on line 103 of the same file.

 await WaitForFileAsync(finalizationStartedFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:105

• The same observation race exists for disposal: the child appends the attempt marker and immediately begins its 10-second sleep, while this stopwatch starts only after the parent polling loop runs. Parent scheduling delay therefore gets subtracted from the measured disposal time and can let a regressed timeout pass. Add a child-to-parent ready marker plus a parent-to-child release marker, starting the stopwatch before releasing disposal to block.

 await WaitForFileAsync(disposalAttemptsFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

[Amaury Levé (Evangelink)]

Addressed the two suppressed observation-race findings from the latest Copilot review in 8a0b77ed4. The generated test host now reports readiness before the timeout path begins and waits for the parent to release it; the parent starts timing before that release, so process startup and scheduling delays are excluded without omitting any of the blocking interval.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the…

Suppressed comments (1)

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:115

• This stopwatch also starts at execution release rather than after Dispose begins (the disposal-attempt marker is written at callback entry). Consequently, the test does not implement the callback-scoped timing described by the PR and includes timeout/pre-disposal work. Either wait for disposalAttemptsFile before starting timing, or revise the PR description to state the actual scope.

 var stopwatch = Stopwatch.StartNew();

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the… View resolved comment

[Amaury Levé (Evangelink)]

Hardcoded wall-clock ceilings made acceptance tests susceptible to loaded CI agents, while one attribute-precedence check raced against the exact configured timeout with no margin.

• Replace raw numeric ceilings with named TimeSpan limits and document their CI allowance.
• Record a monotonic timestamp in the generated child at finalization or disposal entry, so the parent measures only cleanup and teardown without process-startup overhead, polling, or observation races.
• Remove the redundant stopwatch assertion where the reported 1000ms timeout already proves attribute precedence.
• Add contributor guidance for process-level timing assertions.

Validation: packed the repository and ran the affected MTP and MSTest acceptance classes, including the revised lifetime-handler tests across all targeted frameworks.

Fixes#10899

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

What changed in this PR

Hardens acceptance-test timing checks against slow CI agents while preserving regression detection.

Changes:

• Replaces tight numeric ceilings with documented 30-second limits.
• Extends blocking fixtures and removes a redundant timing assertion.
• Adds contributor guidance for process-level timing checks.

File	Description
.github/​copilot-instructions.md	Documents robust timing-assertion practices.
DataConsumerThroughputTests.cs	Adds a CI-tolerant throughput limit.
TestHostProcessLifetimeHandlerTests.cs	Relaxes timing limits and extends blocking operations.
TimeoutWhenExpiresTests.cs	Removes the redundant stopwatch assertion.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight…

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight… View resolved comment

Suppressed comments (2)

Previously missed (1) — in code that hasn't changed since the last review.

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:71

• This still has an observation race: the child writes finalizationStartedFile immediately before entering its 10-second sleep, but the stopwatch starts only when the parent is scheduled and notices that file. If the parent is delayed, some or all of the blocking interval is omitted, so a broken finalization timeout can satisfy the five-second assertion. Use a two-way rendezvous: have the child publish a ready marker and wait for a release marker, then start the stopwatch before releasing it into the blocking callback.

This issue also appears on line 103 of the same file.

 await WaitForFileAsync(finalizationStartedFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:105

• The same observation race exists for disposal: the child appends the attempt marker and immediately begins its 10-second sleep, while this stopwatch starts only after the parent polling loop runs. Parent scheduling delay therefore gets subtracted from the measured disposal time and can let a regressed timeout pass. Add a child-to-parent ready marker plus a parent-to-child release marker, starting the stopwatch before releasing disposal to block.

 await WaitForFileAsync(disposalAttemptsFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

[Amaury Levé (Evangelink)]

Addressed the two suppressed observation-race findings from the latest Copilot review in 8a0b77ed4. The generated test host now reports readiness before the timeout path begins and waits for the parent to release it; the parent starts timing before that release, so process startup and scheduling delays are excluded without omitting any of the blocking interval.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the…

Suppressed comments (1)

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:115

• This stopwatch also starts at execution release rather than after Dispose begins (the disposal-attempt marker is written at callback entry). Consequently, the test does not implement the callback-scoped timing described by the PR and includes timeout/pre-disposal work. Either wait for disposalAttemptsFile before starting timing, or revise the PR description to state the actual scope.

 var stopwatch = Stopwatch.StartNew();

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the… View resolved comment

[Amaury Levé (Evangelink)]

Hardcoded wall-clock ceilings made acceptance tests susceptible to loaded CI agents, while one attribute-precedence check raced against the exact configured timeout with no margin.

• Replace raw numeric ceilings with named TimeSpan limits and document their CI allowance.
• Record a monotonic timestamp in the generated child at finalization or disposal entry, so the parent measures only cleanup and teardown without process-startup overhead, polling, or observation races.
• Remove the redundant stopwatch assertion where the reported 1000ms timeout already proves attribute precedence.
• Add contributor guidance for process-level timing assertions.

Validation: packed the repository and ran the affected MTP and MSTest acceptance classes, including the revised lifetime-handler tests across all targeted frameworks.

Fixes#10899

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

What changed in this PR

Hardens acceptance-test timing checks against slow CI agents while preserving regression detection.

Changes:

• Replaces tight numeric ceilings with documented 30-second limits.
• Extends blocking fixtures and removes a redundant timing assertion.
• Adds contributor guidance for process-level timing checks.

File	Description
.github/​copilot-instructions.md	Documents robust timing-assertion practices.
DataConsumerThroughputTests.cs	Adds a CI-tolerant throughput limit.
TestHostProcessLifetimeHandlerTests.cs	Relaxes timing limits and extends blocking operations.
TimeoutWhenExpiresTests.cs	Removes the redundant stopwatch assertion.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight…

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight… View resolved comment

Suppressed comments (2)

Previously missed (1) — in code that hasn't changed since the last review.

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:71

• This still has an observation race: the child writes finalizationStartedFile immediately before entering its 10-second sleep, but the stopwatch starts only when the parent is scheduled and notices that file. If the parent is delayed, some or all of the blocking interval is omitted, so a broken finalization timeout can satisfy the five-second assertion. Use a two-way rendezvous: have the child publish a ready marker and wait for a release marker, then start the stopwatch before releasing it into the blocking callback.

This issue also appears on line 103 of the same file.

 await WaitForFileAsync(finalizationStartedFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:105

• The same observation race exists for disposal: the child appends the attempt marker and immediately begins its 10-second sleep, while this stopwatch starts only after the parent polling loop runs. Parent scheduling delay therefore gets subtracted from the measured disposal time and can let a regressed timeout pass. Add a child-to-parent ready marker plus a parent-to-child release marker, starting the stopwatch before releasing disposal to block.

 await WaitForFileAsync(disposalAttemptsFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

[Amaury Levé (Evangelink)]

Addressed the two suppressed observation-race findings from the latest Copilot review in 8a0b77ed4. The generated test host now reports readiness before the timeout path begins and waits for the parent to release it; the parent starts timing before that release, so process startup and scheduling delays are excluded without omitting any of the blocking interval.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the…

Suppressed comments (1)

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:115

• This stopwatch also starts at execution release rather than after Dispose begins (the disposal-attempt marker is written at callback entry). Consequently, the test does not implement the callback-scoped timing described by the PR and includes timeout/pre-disposal work. Either wait for disposalAttemptsFile before starting timing, or revise the PR description to state the actual scope.

 var stopwatch = Stopwatch.StartNew();

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the… View resolved comment

[Amaury Levé (Evangelink)]

Hardcoded wall-clock ceilings made acceptance tests susceptible to loaded CI agents, while one attribute-precedence check raced against the exact configured timeout with no margin.

• Replace raw numeric ceilings with named TimeSpan limits and document their CI allowance.
• Record a monotonic timestamp in the generated child at finalization or disposal entry, so the parent measures only cleanup and teardown without process-startup overhead, polling, or observation races.
• Remove the redundant stopwatch assertion where the reported 1000ms timeout already proves attribute precedence.
• Add contributor guidance for process-level timing assertions.

Validation: packed the repository and ran the affected MTP and MSTest acceptance classes, including the revised lifetime-handler tests across all targeted frameworks.

Fixes#10899

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

What changed in this PR

Hardens acceptance-test timing checks against slow CI agents while preserving regression detection.

Changes:

• Replaces tight numeric ceilings with documented 30-second limits.
• Extends blocking fixtures and removes a redundant timing assertion.
• Adds contributor guidance for process-level timing checks.

File	Description
.github/​copilot-instructions.md	Documents robust timing-assertion practices.
DataConsumerThroughputTests.cs	Adds a CI-tolerant throughput limit.
TestHostProcessLifetimeHandlerTests.cs	Relaxes timing limits and extends blocking operations.
TimeoutWhenExpiresTests.cs	Removes the redundant stopwatch assertion.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight…

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — WaitAsync times out only the proxy await; it cancels neither this polling task nor the in-flight… View resolved comment

Suppressed comments (2)

Previously missed (1) — in code that hasn't changed since the last review.

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:71

• This still has an observation race: the child writes finalizationStartedFile immediately before entering its 10-second sleep, but the stopwatch starts only when the parent is scheduled and notices that file. If the parent is delayed, some or all of the blocking interval is omitted, so a broken finalization timeout can satisfy the five-second assertion. Use a two-way rendezvous: have the child publish a ready marker and wait for a release marker, then start the stopwatch before releasing it into the blocking callback.

This issue also appears on line 103 of the same file.

 await WaitForFileAsync(finalizationStartedFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:105

• The same observation race exists for disposal: the child appends the attempt marker and immediately begins its 10-second sleep, while this stopwatch starts only after the parent polling loop runs. Parent scheduling delay therefore gets subtracted from the measured disposal time and can let a regressed timeout pass. Add a child-to-parent ready marker plus a parent-to-child release marker, starting the stopwatch before releasing disposal to block.

 await WaitForFileAsync(disposalAttemptsFile, markerTimeout.Token);
markerTimeout.CancelAfter(Timeout.InfiniteTimeSpan);
var stopwatch = Stopwatch.StartNew();

[Amaury Levé (Evangelink)]

Addressed the two suppressed observation-race findings from the latest Copilot review in 8a0b77ed4. The generated test host now reports readiness before the timeout path begins and waits for the parent to release it; the parent starts timing before that release, so process startup and scheduling delays are excluded without omitting any of the blocking interval.

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: 1

New issues introduced by this change (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the…

Suppressed comments (1)

test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/TestHostProcessLifetimeHandlerTests.cs:115

• This stopwatch also starts at execution release rather than after Dispose begins (the disposal-attempt marker is written at callback entry). Consequently, the test does not implement the callback-scoped timing described by the PR and includes timeout/pre-disposal work. Either wait for disposalAttemptsFile before starting timing, or revise the PR description to state the actual scope.

 var stopwatch = Stopwatch.StartNew();

[Copilot]

Copilot review overview

Review tier: Balanced
Findings: None

Issues resolved since last review (1)

Severity	Finding
	test/​IntegrationTests/​Microsoft.Testing.Platform.Acceptance.IntegrationTests/​TestHostProcessLifetimeHandlerTests.cs — Stopwatch starts when execution is released, not when OnTestHostProcessExitedAsync begins (the… View resolved comment