Fix async transformations #2230

TechTalk.SpecFlow/Bindings/AsyncMethodHelper.cs

@@ -0,0 +1,55 @@
+using System;
+using System.Threading.Tasks;
+using TechTalk.SpecFlow.Bindings.Reflection;
+
+namespace TechTalk.SpecFlow.Bindings
+{
+ internal static class AsyncMethodHelper
+ {
+ private static readonly IBindingType TaskOfT = new RuntimeBindingType(typeof(Task<>));
+
+ private static bool IsTaskOfT(Type type, out Type typeArg)
+ {
+ typeArg = null;
+ var isTaskOfT = type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Task<>);
+ if (isTaskOfT)
+ {
+ typeArg = type.GetGenericArguments()[0];
+ }
+ return isTaskOfT;
+ }
+
+ private static bool IsValueTaskOfT(Type type, out Type typeArg)
+ {
+ typeArg = null;
+#if NETFRAMEWORK
+ return false;
+#else
+ var isTaskOfT = type.IsGenericType && type.GetGenericTypeDefinition() == typeof(ValueTask<>);
+ if (isTaskOfT)
+ {
+ typeArg = type.GetGenericArguments()[0];
+ }
+ return isTaskOfT;
+#endif
+ }
+
+ private static bool IsAwaitableOfT(Type type, out Type typeArg)
+ {
+ return IsTaskOfT(type, out typeArg) || IsValueTaskOfT(type, out typeArg);
+ }
+
+ public static IBindingType GetAwaitableReturnType(this IBindingMethod bindingMethod)
+ {
+ var returnType = bindingMethod.ReturnType;
+
+ if (returnType is RuntimeBindingType runtimeReturnType &&
+ IsAwaitableOfT(runtimeReturnType.Type, out var typeArg))
+ {
+ return new RuntimeBindingType(typeArg);
+ }
+
+ return returnType;
+ }
+ }
+}

TechTalk.SpecFlow/Bindings/StepArgumentTypeConverter.cs

@@ -96,7 +96,8 @@ public bool CanConvert(object value, IBindingType typeToConvertTo, CultureInfo c
 
  private bool CanConvert(IStepArgumentTransformationBinding stepTransformationBinding, object valueToConvert, IBindingType typeToConvertTo)
  {
- if (!stepTransformationBinding.Method.ReturnType.TypeEquals(typeToConvertTo))
+ var awaitableReturnType = stepTransformationBinding.Method.GetAwaitableReturnType();
+ if (!awaitableReturnType.TypeEquals(typeToConvertTo))
  return false;
 
  if (stepTransformationBinding.Regex != null && valueToConvert is string stringValue)

Tests/TechTalk.SpecFlow.RuntimeTests/StepTransformationTests.cs

@@ -31,6 +31,20 @@ public User Create(string name)
  return new User {Name = name};
  }
 
+ [StepArgumentTransformation("user (w+)")]
+ public async Task<User> AsyncCreate(string name)
+ {
+ await Task.Yield();
+ return new User {Name = name};
+ }
+
+ [StepArgumentTransformation("user (w+)")]
+ public async ValueTask<User> AsyncCreateValueTask(string name)
+ {
+ await Task.Yield();
+ return new User {Name = name};
+ }
+
  [StepArgumentTransformation]
  public IEnumerable<User> CreateUsers(Table table)
  {
@@ -156,7 +170,44 @@ public async Task TypeToTypeConverterShouldConvertTableToTable()
  public async Task StepArgumentTypeConverterShouldUseUserConverterForConversion()
  {
  UserCreator stepTransformationInstance = new UserCreator();
- var transformMethod = new RuntimeBindingMethod(stepTransformationInstance.GetType().GetMethod("Create"));
+ var transformMethod = new RuntimeBindingMethod(stepTransformationInstance.GetType().GetMethod(nameof(UserCreator.Create)));
+ var stepTransformationBinding = CreateStepTransformationBinding(@"user (\w+)", transformMethod);
+ stepTransformations.Add(stepTransformationBinding);
+ var resultUser = new User();
+ methodBindingInvokerStub
+ .Setup(i => i.InvokeBindingAsync(stepTransformationBinding, It.IsAny<IContextManager>(), It.IsAny<object[]>(), It.IsAny<ITestTracer>(), It.IsAny<DurationHolder>()))
+ .ReturnsAsync(resultUser);
+
+ var stepArgumentTypeConverter = CreateStepArgumentTypeConverter();
+
+ var result = await stepArgumentTypeConverter.ConvertAsync("user xyz", typeof(User), new CultureInfo("en-US", false));
+ result.Should().Be(resultUser);
+ }
+
+ [Fact]
+ public async Task StepArgumentTypeConverterShouldUseAsyncUserConverterForConversion()
+ {
+ UserCreator stepTransformationInstance = new UserCreator();
+ var transformMethod = new RuntimeBindingMethod(stepTransformationInstance.GetType().GetMethod(nameof(UserCreator.AsyncCreate)));
+ var stepTransformationBinding = CreateStepTransformationBinding(@"user (\w+)", transformMethod);
+ stepTransformations.Add(stepTransformationBinding);
+ var resultUser = new User();
+ methodBindingInvokerStub
+ .Setup(i => i.InvokeBindingAsync(stepTransformationBinding, It.IsAny<IContextManager>(), It.IsAny<object[]>(), It.IsAny<ITestTracer>(), It.IsAny<DurationHolder>()))
+ .ReturnsAsync(resultUser);
+
+ var stepArgumentTypeConverter = CreateStepArgumentTypeConverter();
+
+ var result = await stepArgumentTypeConverter.ConvertAsync("user xyz", typeof(User), new CultureInfo("en-US", false));
+ result.Should().Be(resultUser);
+ }
+
+#if !NETFRAMEWORK
+ [Fact]
+ public async Task StepArgumentTypeConverterShouldUseAsyncValueTaskUserConverterForConversion()
+ {
+ UserCreator stepTransformationInstance = new UserCreator();
+ var transformMethod = new RuntimeBindingMethod(stepTransformationInstance.GetType().GetMethod(nameof(UserCreator.AsyncCreateValueTask)));
  var stepTransformationBinding = CreateStepTransformationBinding(@"user (\w+)", transformMethod);
  stepTransformations.Add(stepTransformationBinding);
  var resultUser = new User();
@@ -169,6 +220,7 @@ public async Task StepArgumentTypeConverterShouldUseUserConverterForConversion()
  var result = await stepArgumentTypeConverter.ConvertAsync("user xyz", typeof(User), new CultureInfo("en-US", false));
  result.Should().Be(resultUser);
  }
+#endif
 
  private StepArgumentTypeConverter CreateStepArgumentTypeConverter()
  {
@@ -181,7 +233,7 @@ public async Task ShouldUseStepArgumentTransformationToConvertTable()
  var table = new Table("Name");
 
  UserCreator stepTransformationInstance = new UserCreator();
- var transformMethod = new RuntimeBindingMethod(stepTransformationInstance.GetType().GetMethod("CreateUsers"));
+ var transformMethod = new RuntimeBindingMethod(stepTransformationInstance.GetType().GetMethod(nameof(UserCreator.CreateUsers)));
  var stepTransformationBinding = CreateStepTransformationBinding(@"", transformMethod);
  stepTransformations.Add(stepTransformationBinding);
  var resultUsers = new User[3];

changelog.txt

@@ -9,6 +9,7 @@ Features:
 + Add an option to colorize test result output
 + Support for using Cucumber Expressions for step definitions.
 + Support Rule tags (can be used for hook filters, scoping and access through 'ScenarioInfo.CombinedTags')
++ Support for async step argument transformations. Fixes #2230
 
 Changes:
 + Existing step definition expressions detected to be either regular or cucumber expression. Check https://docs.specflow.org/projects/specflow/en/latest/Guides/UpgradeSpecFlow3To4.html for potential upgrade issues.

docs/Bindings/Asynchronous-Bindings.md

@@ -20,3 +20,5 @@ public async Task HttpClientGet(string url)
  _httpResponseMessage = await _httpClient.GetAsync(url);
 }
 ```
+
+From SpecFlow v4 you can also use asynchronous [step argument transformations](Step-Argument-Conversions.md).