Fix race condition in AutomaticInputRequiredStatusTests polling logic

[Copilot]

Fix intermittent test failure in AutomaticInputRequiredStatusTests

Root Cause

The test TaskStatus_TransitionsToInputRequired_DuringElicitAsync (and its sibling TaskStatus_TransitionsToInputRequired_DuringSampleAsync) has a race condition in its polling loop. The loop continues only while the task status is Working, but the expected behavior is that the status should transition from Working → InputRequired → Working → Completed.

When the test polls the task store while the status is temporarily in the InputRequired state, the loop exits early and the test fails because it expects Completed but finds InputRequired.

Solution

Updated the polling condition in both tests to continue while the status is not Completed. This allows the tests to correctly wait for the task to reach completion regardless of the timing of the polling.

Changes Made

• Modified TaskStatus_TransitionsToInputRequired_DuringSampleAsync polling loop condition (line 122)
• Modified TaskStatus_TransitionsToInputRequired_DuringElicitAsync polling loop condition (line 221)
• Simplified condition to: finalStatus?.Status is not McpTaskStatus.Completed

Verification

• Understand the issue and root cause
• Fix the polling logic in both failing tests to continue while status is not completed
• Run the specific failing tests to validate the fix - both tests now pass consistently
• Run the full test suite to ensure no regressions - all tests pass
• Apply feedback to use simpler pattern matching syntax

Original prompt

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This section details on the original issue you should resolve

<issue_title>AutomaticInputRequiredStatusTests.TaskStatus_TransitionsToInputRequired_DuringElicitAsync intermittently fails (timing/race)</issue_title>
<issue_description>https://github.com/modelcontextprotocol/csharp-sdk/actions/runs/21503213903/job/61953813945?pr=1070

  Failed ModelContextProtocol.Tests.Server.AutomaticInputRequiredStatusTests.TaskStatus_TransitionsToInputRequired_DuringElicitAsync [550 ms]
  Error Message:
   Assert.Equal() Failure: Values differ
Expected: Completed
Actual:   InputRequired
  Stack Trace:
     at ModelContextProtocol.Tests.Server.AutomaticInputRequiredStatusTests.TaskStatus_TransitionsToInputRequired_DuringElicitAsync() in /_/tests/ModelContextProtocol.Tests/Server/AutomaticInputRequiredStatusTests.cs:line 228
   at ModelContextProtocol.Tests.Server.AutomaticInputRequiredStatusTests.TaskStatus_TransitionsToInputRequired_DuringElicitAsync() in /_/tests/ModelContextProtocol.Tests/Server/AutomaticInputRequiredStatusTests.cs:line 228
--- End of stack trace from previous location ---

csharp-sdk/tests/ModelContextProtocol.Tests/Server/AutomaticInputRequiredStatusTests.cs

Lines 215 to 228 in f9dec13

	do
	{
	await Task.Delay(100, TestContext.Current.CancellationToken);
	finalStatus = await taskStore.GetTaskAsync(mcpTask.TaskId, cancellationToken: TestContext.Current.CancellationToken);
	maxAttempts--;
	}
	while (finalStatus?.Status == McpTaskStatus.Working && maxAttempts > 0);
	// Assert - Status should have been InputRequired during elicitation
	Assert.Contains(McpTaskStatus.InputRequired, statusesDuringElicitation);
	// Final status should be Completed
	Assert.NotNull(finalStatus);
	Assert.Equal(McpTaskStatus.Completed, finalStatus.Status);

It looks to me like the task briefly transitioned status from Working to InputRequired and this caused the test to stop polling. The test then failed when it expected the test to transition to Completed.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes AutomaticInputRequiredStatusTests.TaskStatus_TransitionsToInputRequired_DuringElicitAsync intermittently fails (timing/race) #1222

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