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perf: avoid GetParameters() allocation in test-invocation hot path#9671

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Merged
Amaury Levé (Evangelink) merged 1 commit into from
Jul 7, 2026
Merged

perf: avoid GetParameters() allocation in test-invocation hot path #9671

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4 changes: 2 additions & 2 deletions src/Adapter/MSTestAdapter.PlatformServices/Execution/TestMethodInfo.Execution.cs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -144,7 +144,7 @@ private async Task<TestResult> ExecuteInternalAsync(object?[]? arguments, Cancel
{
if (_executionContext is null)
{
Task? invokeResult = MethodInfo.GetInvokeResultAsync(_classInstance, arguments);
Task? invokeResult = MethodInfo.GetInvokeResultWithParametersAsync(_classInstance, ParameterTypes, arguments);
if (invokeResult is not null)
{
await invokeResult.ConfigureAwait(true);
Expand All@@ -161,7 +161,7 @@ private async Task<TestResult> ExecuteInternalAsync(object?[]? arguments, Cancel
#if NETFRAMEWORK
CallContext.HostContext = _hostContext;
#endif
Task? invokeResult = MethodInfo.GetInvokeResultAsync(_classInstance, arguments);
Task? invokeResult = MethodInfo.GetInvokeResultWithParametersAsync(_classInstance, ParameterTypes, arguments);
if (invokeResult is not null)
{
await invokeResult.ConfigureAwait(false);
Expand Down
24 changes: 14 additions & 10 deletions src/Adapter/MSTestAdapter.PlatformServices/Extensions/MethodInfoExtensions.cs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -117,12 +117,17 @@ private static bool IsValueTask(this MethodInfo method)
}

internal static Task? GetInvokeResultAsync(this MethodInfo methodInfo, object? classInstance, params object?[]? arguments)
{
ParameterInfo[]? methodParameters = methodInfo.GetParameters();
// MethodInfo.GetParameters() allocates a fresh ParameterInfo[] on every call (CLR safety
// guarantee). Non-hot-path callers go through this thin wrapper; the hot path (data-driven
// test invocation) calls GetInvokeResultWithParametersAsync directly with an already-cached
// array to avoid the per-invocation allocation.
=> methodInfo.GetInvokeResultWithParametersAsync(classInstance, methodInfo.GetParameters(), arguments);

internal static Task? GetInvokeResultWithParametersAsync(this MethodInfo methodInfo, object? classInstance, ParameterInfo[] methodParameters, params object?[]? arguments)
{
// check if test method expected parameter values but no test data was provided,
// throw error with appropriate message.
if (methodParameters is { Length: > 0 } && arguments == null)
if (methodParameters is { Length: > 0 } && arguments is null)
{
throw new TestFailedException(
UnitTestOutcome.Error,
Expand DownExpand Up@@ -150,7 +155,7 @@ private static bool IsValueTask(this MethodInfo method)
// IndexOutOfRangeException. Mirror the reflection path's friendly diagnostic instead. We
// only validate the count here — a type mismatch surfaces as the test's own exception and
// must not be reinterpreted as an arguments error.
int expectedParameterCount = methodParameters?.Length ?? 0;
int expectedParameterCount = methodParameters.Length;
int providedArgumentCount = sourceGeneratedArguments?.Length ?? 0;
if (expectedParameterCount != providedArgumentCount)
{
Expand All@@ -162,7 +167,7 @@ private static bool IsValueTask(this MethodInfo method)
methodInfo.DeclaringType!.FullName,
methodInfo.Name,
expectedParameterCount,
string.Join(", ", methodParameters?.Select(p => p.ParameterType.Name) ?? []),
string.Join(", ", methodParameters.Select(p => p.ParameterType.Name)),
providedArgumentCount,
string.Join(", ", sourceGeneratedArguments?.Select(a => a?.GetType().Name ?? "null") ?? [])));
}
Expand All@@ -184,7 +189,7 @@ private static bool IsValueTask(this MethodInfo method)
}
else
{
int methodParametersLengthOrZero = methodParameters?.Length ?? 0;
int methodParametersLengthOrZero = methodParameters.Length;
int argumentsLengthOrZero = arguments?.Length ?? 0;

#if WINDOWS_UWP
Expand All@@ -203,7 +208,7 @@ private static bool IsValueTask(this MethodInfo method)
{
if (methodInfo.IsGenericMethod)
{
methodInfo = ConstructGenericMethod(methodInfo, arguments);
methodInfo = ConstructGenericMethod(methodInfo, methodParameters, arguments);
}

invokeResult = methodInfo.Invoke(classInstance, arguments);
Expand All@@ -218,7 +223,7 @@ private static bool IsValueTask(this MethodInfo method)
methodInfo.DeclaringType!.FullName,
methodInfo.Name,
methodParametersLengthOrZero,
string.Join(", ", methodParameters?.Select(p => p.ParameterType.Name) ?? []),
string.Join(", ", methodParameters.Select(p => p.ParameterType.Name)),
argumentsLengthOrZero,
string.Join(", ", arguments?.Select(a => a?.GetType().Name ?? "null") ?? [])), ex);
}
Expand DownExpand Up@@ -285,7 +290,7 @@ private static void InferGenerics(Type parameterType, Type argumentType, List<(T
// public void TestMethod<T1, T2>(T2 p0, T1, p1) { }
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2060:Call to 'System.Reflection.MethodInfo.MakeGenericMethod' can not be statically analyzed.", Justification = "Generic test methods with substituted type arguments are part of MSTest's reflection-mode adapter. Native AOT support relies on MSTest source-generated metadata, not on this code path.")]
[UnconditionalSuppressMessage("Aot", "IL3050:Avoid calling members annotated with 'RequiresDynamicCodeAttribute' when publishing as Native AOT", Justification = "Generic test methods with substituted type arguments are part of MSTest's reflection-mode adapter. Native AOT support relies on MSTest source-generated metadata, not on this code path.")]
private static MethodInfo ConstructGenericMethod(MethodInfo methodInfo, object?[]? arguments)
private static MethodInfo ConstructGenericMethod(MethodInfo methodInfo, ParameterInfo[] parameters, object?[]? arguments)
{
DebugEx.Assert(methodInfo.IsGenericMethod, "ConstructGenericMethod should only be called for a generic method.");

Expand All@@ -304,7 +309,6 @@ private static MethodInfo ConstructGenericMethod(MethodInfo methodInfo, object?[
map[i] = (genericDefinitions[i], null);
}

ParameterInfo[] parameters = methodInfo.GetParameters();
for (int i = 0; i < parameters.Length; i++)
{
Type parameterType = parameters[i].ParameterType;
Expand Down