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feat: Add bail to MTP test runner #3674

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bd671e9
Cache env variables for mtp servers
richardwerkman Jun 28, 2026
4436995
Add bail feature to MTP
richardwerkman Jun 28, 2026
3eaa9ce
Merge branch 'master' into feature/mtp-performance-2
richardwerkman Jun 29, 2026
8e4adc4
Merge branch 'feature/mtp-performance-2' of https://github.com/stryke…
richardwerkman Jun 29, 2026
9caa17e
Fix IStrykerOptions
richardwerkman Jun 28, 2026
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77 changes: 66 additions & 11 deletions src/Stryker.TestRunner.MicrosoftTestPlatform.UnitTest/AssemblyTestServerTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -316,15 +316,15 @@ public async Task RunTestsAsync_ShouldCallClientRunTests()
var listener = new TestNodeUpdatesResponseListener(Guid.NewGuid(), _ => Task.CompletedTask);
listener.Complete();

_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null))
_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null, It.IsAny<CancellationToken>()))
.ReturnsAsync(listener);

using var server = CreateServer();
await server.StartAsync();
var result = await server.RunTestsAsync(null);

result.ShouldNotBeNull();
_clientMock.Verify(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null), Times.Once);
_clientMock.Verify(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null, It.IsAny<CancellationToken>()), Times.Once);
}

[TestMethod]
Expand All @@ -336,14 +336,14 @@ public async Task RunTestsAsync_ShouldPassTestNodesToClient()
var listener = new TestNodeUpdatesResponseListener(Guid.NewGuid(), _ => Task.CompletedTask);
listener.Complete();

_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), testNodes))
_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), testNodes, It.IsAny<CancellationToken>()))
.ReturnsAsync(listener);

using var server = CreateServer();
await server.StartAsync();
await server.RunTestsAsync(testNodes);

_clientMock.Verify(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), testNodes), Times.Once);
_clientMock.Verify(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), testNodes, It.IsAny<CancellationToken>()), Times.Once);
}

[TestMethod]
Expand All @@ -359,8 +359,8 @@ public async Task RunTestsAsync_ShouldCollectTestResults()
new TestNodeUpdate(failedNode, "parent")
};

_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null))
.Returns<Guid, Func<TestNodeUpdate[], Task>, TestNode[]?>(async (id, callback, _) =>
_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null, It.IsAny<CancellationToken>()))
.Returns<Guid, Func<TestNodeUpdate[], Task>, TestNode[]?, CancellationToken>(async (id, callback, _, _) =>
{
await callback(updates);
var listener = new TestNodeUpdatesResponseListener(id, _ => Task.CompletedTask);
Expand All @@ -383,7 +383,7 @@ public async Task RunTestsAsync_WithTimeout_ShouldReturnTimedOutFalse_WhenComple
var listener = new TestNodeUpdatesResponseListener(Guid.NewGuid(), _ => Task.CompletedTask);
listener.Complete();

_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null))
_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null, It.IsAny<CancellationToken>()))
.ReturnsAsync(listener);

using var server = CreateServer();
Expand All @@ -401,7 +401,7 @@ public async Task RunTestsAsync_WithTimeout_ShouldReturnTimedOutTrue_WhenTimesOu
// Listener that never completes
var listener = new TestNodeUpdatesResponseListener(Guid.NewGuid(), _ => Task.CompletedTask);

_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null))
_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null, It.IsAny<CancellationToken>()))
.ReturnsAsync(listener);

using var server = CreateServer();
Expand All @@ -418,7 +418,7 @@ public async Task RunTestsAsync_WithTimeout_ShouldThrowTestHostCrashed_WhenProce

// Listener that never completes (a crashed host never sends a completion signal)
var listener = new TestNodeUpdatesResponseListener(Guid.NewGuid(), _ => Task.CompletedTask);
_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null))
_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null, It.IsAny<CancellationToken>()))
.ReturnsAsync(listener);

using var server = CreateServer();
Expand All @@ -439,7 +439,7 @@ public async Task RunTestsAsync_WithoutTimeout_ShouldThrowTestHostCrashed_WhenPr
SetupSuccessfulConnection();

var listener = new TestNodeUpdatesResponseListener(Guid.NewGuid(), _ => Task.CompletedTask);
_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null))
_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null, It.IsAny<CancellationToken>()))
.ReturnsAsync(listener);

using var server = CreateServer();
Expand All @@ -452,13 +452,68 @@ public async Task RunTestsAsync_WithoutTimeout_ShouldThrowTestHostCrashed_WhenPr
async () => await server.RunTestsAsync(null));
}

[TestMethod]
public async Task RunTestsAsync_ShouldInvokeBailCallback_AndReturnCollectedResults()
{
SetupSuccessfulConnection();

var failedNode = new TestNode("uid-1", "Test1", "action", "failed");
var updates = new[] { new TestNodeUpdate(failedNode, "parent") };

_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null, It.IsAny<CancellationToken>()))
.Returns<Guid, Func<TestNodeUpdate[], Task>, TestNode[]?, CancellationToken>(async (id, callback, _, _) =>
{
await callback(updates);
var listener = new TestNodeUpdatesResponseListener(id, _ => Task.CompletedTask);
listener.Complete();
return listener;
});

IReadOnlyList<TestNodeUpdate>? observed = null;
using var server = CreateServer();
await server.StartAsync();

var (results, timedOut) = await server.RunTestsAsync(null, TimeSpan.FromSeconds(10), batch =>
{
observed = batch;
return true; // request bail on first batch
});

// The streamed results are surfaced to the bail callback and still returned to the caller.
observed.ShouldNotBeNull();
observed!.Single().Node.Uid.ShouldBe("uid-1");
results.Count.ShouldBe(1);
timedOut.ShouldBeFalse();
}

[TestMethod]
public async Task RunTestsAsync_ShouldPassCancellableToken_ToClient_ForBail()
{
SetupSuccessfulConnection();

CancellationToken capturedToken = default;
var listener = new TestNodeUpdatesResponseListener(Guid.NewGuid(), _ => Task.CompletedTask);
listener.Complete();

_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null, It.IsAny<CancellationToken>()))
.Callback<Guid, Func<TestNodeUpdate[], Task>, TestNode[]?, CancellationToken>((_, _, _, token) => capturedToken = token)
.ReturnsAsync(listener);

using var server = CreateServer();
await server.StartAsync();
await server.RunTestsAsync(null, TimeSpan.FromSeconds(10), _ => false);

// A real, cancellable token is handed to the client so a bail can propagate $/cancelRequest.
capturedToken.CanBeCanceled.ShouldBeTrue();
}

[TestMethod]
public async Task RunTestsAsync_WithTimeout_ShouldReturnTimedOutTrue_WhenRpcCallBlocks()
{
SetupSuccessfulConnection();

// RPC call that never returns (simulates server stuck in infinite loop)
_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null))
_clientMock.Setup(c => c.RunTestsAsync(It.IsAny<Guid>(), It.IsAny<Func<TestNodeUpdate[], Task>>(), null, It.IsAny<CancellationToken>()))
.Returns(new TaskCompletionSource<ResponseListener>().Task);

using var server = CreateServer();
Expand Down
133 changes: 130 additions & 3 deletions ...ryker.TestRunner.MicrosoftTestPlatform.UnitTest/SingleMicrosoftTestPlatformRunnerTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -691,6 +691,133 @@ bool Update(IReadOnlyList<IMutant> _, ITestIdentifiers failed, ITestIdentifiers
result.ResultMessage.ShouldContain("crash"); // failure reason is surfaced, not swallowed
}

// --- Bail-on-first-failure tests ---
//
// The MTP runner now mirrors the VsTest runner: streamed results are fed to the mutation update
// handler as they arrive, and once every tested mutant's fate is decided the remaining tests/assemblies
// are skipped. The update handler returns true while mutants are pending and always returns true when
// --disable-bail is set, so honouring its return value is all that is needed to honour that option.

[TestMethod, Timeout(1000)]
public async Task TestMultipleMutantsAsync_BailsOut_SkippingRemainingAssemblies_OnceMutantIsKilled()
{
const string assemblyA = "/a.dll";
const string assemblyB = "/b.dll";
_testsByAssembly[assemblyA] = [new TestNode("a-uid", "TestA", "test", TestNodeStates.Failed)];
_testsByAssembly[assemblyB] = [new TestNode("b-uid", "TestB", "test", TestNodeStates.Passed)];

var project = new Mock<IProjectAndTests>();
project.Setup(x => x.GetTestAssemblies()).Returns([assemblyA, assemblyB]);

var mutant = new Mock<IMutant>();
mutant.Setup(m => m.Id).Returns(1);

var runAssemblies = new List<string>();
using var runner = new StreamingAssemblyRunner(
_testsByAssembly, _testDescriptions, _testSet, _discoveryLock, runAssemblies);

// Bail (return false) as soon as any test has failed; continue otherwise.
bool Update(IReadOnlyList<IMutant> _, ITestIdentifiers failed, ITestIdentifiers __, ITestIdentifiers ___)
=> !failed.GetIdentifiers().Any();

await runner.TestMultipleMutantsAsync(project.Object, null, [mutant.Object], Update);

// Assembly A streamed a failing test, so the run bailed and never touched assembly B.
runAssemblies.ShouldBe([assemblyA]);
}

[TestMethod, Timeout(1000)]
public async Task TestMultipleMutantsAsync_DoesNotBail_WhenUpdateHandlerKeepsRunning()
{
// Mirrors --disable-bail: the handler always returns true, so every assembly must run even
// after a test fails.
const string assemblyA = "/a.dll";
const string assemblyB = "/b.dll";
_testsByAssembly[assemblyA] = [new TestNode("a-uid", "TestA", "test", TestNodeStates.Failed)];
_testsByAssembly[assemblyB] = [new TestNode("b-uid", "TestB", "test", TestNodeStates.Passed)];

var project = new Mock<IProjectAndTests>();
project.Setup(x => x.GetTestAssemblies()).Returns([assemblyA, assemblyB]);

var mutant = new Mock<IMutant>();
mutant.Setup(m => m.Id).Returns(1);

var runAssemblies = new List<string>();
using var runner = new StreamingAssemblyRunner(
_testsByAssembly, _testDescriptions, _testSet, _discoveryLock, runAssemblies);

bool Update(IReadOnlyList<IMutant> _, ITestIdentifiers __, ITestIdentifiers ___, ITestIdentifiers ____) => true;

await runner.TestMultipleMutantsAsync(project.Object, null, [mutant.Object], Update);

runAssemblies.ShouldBe([assemblyA, assemblyB]);
}

[TestMethod, Timeout(1000)]
public async Task TestMultipleMutantsAsync_FeedsStreamedResultsToUpdateHandler_BeforeRunCompletes()
{
const string assembly = "/a.dll";
_testsByAssembly[assembly] = [new TestNode("a-uid", "TestA", "test", TestNodeStates.Failed)];

var project = new Mock<IProjectAndTests>();
project.Setup(x => x.GetTestAssemblies()).Returns([assembly]);

var mutant = new Mock<IMutant>();
mutant.Setup(m => m.Id).Returns(1);

var runAssemblies = new List<string>();
using var runner = new StreamingAssemblyRunner(
_testsByAssembly, _testDescriptions, _testSet, _discoveryLock, runAssemblies);

ITestIdentifiers? capturedFailed = null;
bool Update(IReadOnlyList<IMutant> _, ITestIdentifiers failed, ITestIdentifiers __, ITestIdentifiers ___)
{
capturedFailed = failed;
return false;
}

await runner.TestMultipleMutantsAsync(project.Object, null, [mutant.Object], Update);

// The failing test was surfaced to the handler via the incremental streaming path.
capturedFailed.ShouldNotBeNull();
capturedFailed!.GetIdentifiers().ShouldContain("a-uid");
}

/// <summary>
/// Simulates the server streaming each discovered test's result to the bail callback during an assembly
/// run, without starting a real test host. Records the assemblies that were actually run so a test can
/// assert which ones were skipped after a bail.
/// </summary>
private sealed class StreamingAssemblyRunner : SingleMicrosoftTestPlatformRunner
{
private readonly List<string> _runAssemblies;

public StreamingAssemblyRunner(
Dictionary<string, List<TestNode>> testsByAssembly,
Dictionary<string, MtpTestDescription> testDescriptions,
TestSet testSet,
object discoveryLock,
List<string> runAssemblies)
: base(0, testsByAssembly, testDescriptions, testSet, discoveryLock, NullLogger.Instance)
=> _runAssemblies = runAssemblies;

internal override Task<(TestRunResult? Result, bool TimedOut, List<TestNode>? DiscoveredTests)> RunAssemblyTestsAsync(
string assembly, ITimeoutValueCalculator? timeoutCalc, Func<IReadOnlyList<TestNodeUpdate>, bool>? shouldBail = null)
{
_runAssemblies.Add(assembly);
var discovered = GetDiscoveredTests(assembly) ?? [];

// Simulate the server streaming the discovered tests' results to the bail callback.
shouldBail?.Invoke(discovered.Select(t => new TestNodeUpdate(t, "root")).ToList());

var result = BuildTestRunResult(
discovered.Select(t => new TestNodeUpdate(t, "root")).ToList(),
discovered.Count,
TimeSpan.Zero);
return Task.FromResult<(TestRunResult?, bool, List<TestNode>?)>((result, false, discovered));
}
}

/// <summary>
/// Simulates an assembly whose test host crashes: <see cref="RunAssemblyTestsAsync"/> returns the
/// failure sentinel produced by the real exception path, without starting any server process.
Expand All @@ -709,7 +836,7 @@ public CrashingAssemblyRunner(
=> _discovered = discovered;

internal override Task<(TestRunResult? Result, bool TimedOut, List<TestNode>? DiscoveredTests)> RunAssemblyTestsAsync(
string assembly, ITimeoutValueCalculator? timeoutCalc)
string assembly, ITimeoutValueCalculator? timeoutCalc, Func<IReadOnlyList<TestNodeUpdate>, bool>? shouldBail = null)
=> Task.FromResult<(TestRunResult?, bool, List<TestNode>?)>(
(new TestRunResult(false, "simulated test host crash"), false, _discovered));
}
Expand Down Expand Up @@ -1448,7 +1575,7 @@ public TimeoutSimulatingRunner(
: base(id, testsByAssembly, testDescriptions, testSet, discoveryLock, logger) { }

internal override Task<(TestRunResult? Result, bool TimedOut, List<TestNode>? DiscoveredTests)> RunAssemblyTestsAsync(
string assembly, ITimeoutValueCalculator? timeoutCalc)
string assembly, ITimeoutValueCalculator? timeoutCalc, Func<IReadOnlyList<TestNodeUpdate>, bool>? shouldBail = null)
{
var discoveredTests = GetDiscoveredTests(assembly);
var result = new TestRunResult(
Expand All @@ -1475,7 +1602,7 @@ public NoTimeoutSimulatingRunner(
: base(id, testsByAssembly, testDescriptions, testSet, discoveryLock, logger) { }

internal override Task<(TestRunResult? Result, bool TimedOut, List<TestNode>? DiscoveredTests)> RunAssemblyTestsAsync(
string assembly, ITimeoutValueCalculator? timeoutCalc)
string assembly, ITimeoutValueCalculator? timeoutCalc, Func<IReadOnlyList<TestNodeUpdate>, bool>? shouldBail = null)
{
var discoveredTests = GetDiscoveredTests(assembly);
var result = new TestRunResult(
Expand Down
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