Fix StackOverflowException when using [StepArgumentTransformation] with same input and output type

CHANGELOG.md

@@ -12,6 +12,7 @@
 * Support for JSON files added to SpecFlow.ExternalData
 * Fix: #120 Capture ExecutionContext after every binding invoke
 * MsTest: Use ClassCleanupBehavior.EndOfClass instead of custom implementation (preparation for MsTest v4.0)
+* Fix: #71 StackOverflowException when using [StepArgumentTransformation] with same input and output type (for example string)
 
 # v1.0.1 - 2024-02-16
 

Reqnroll/Bindings/StepArgumentTypeConverter.cs

@@ -38,11 +38,16 @@ protected virtual IStepArgumentTransformationBinding GetMatchingStepTransformati
         }
 
         public async Task<object> ConvertAsync(object value, IBindingType typeToConvertTo, CultureInfo cultureInfo)
+        {
+            return await ConvertAsync(value, typeToConvertTo, cultureInfo, null);
+        }
+
+        private async Task<object> ConvertAsync(object value, IBindingType typeToConvertTo, CultureInfo cultureInfo, IStepArgumentTransformationBinding lastBindingUsed)
         {
             if (value == null) throw new ArgumentNullException(nameof(value));
 
             var stepTransformation = GetMatchingStepTransformation(value, typeToConvertTo, true);
-            if (stepTransformation != null)
+            if (stepTransformation != null && lastBindingUsed != stepTransformation)
                 return await DoTransformAsync(stepTransformation, value, cultureInfo);
 
             if (typeToConvertTo is RuntimeBindingType convertToType && convertToType.Type.IsInstanceOfType(value))
@@ -55,16 +60,16 @@ private async Task<object> DoTransformAsync(IStepArgumentTransformationBinding s
         {
             object[] arguments;
             if (stepTransformation.Regex != null && value is string stringValue)
-                arguments = await GetStepTransformationArgumentsFromRegexAsync(stepTransformation, stringValue, cultureInfo);
+                arguments = await GetStepTransformationArgumentsFromRegexAsync(stepTransformation, stringValue, cultureInfo, stepTransformation);
             else
-                arguments = new[] { await ConvertAsync(value, stepTransformation.Method.Parameters.ElementAtOrDefault(0)?.Type ?? new RuntimeBindingType(typeof(object)), cultureInfo)};
+                arguments = new[] { await ConvertAsync(value, stepTransformation.Method.Parameters.ElementAtOrDefault(0)?.Type ?? new RuntimeBindingType(typeof(object)), cultureInfo, stepTransformation) };
 
             var result = await bindingInvoker.InvokeBindingAsync(stepTransformation, contextManager, arguments, testTracer, new DurationHolder());
 
             return result;
         }
 
-        private async Task<object[]> GetStepTransformationArgumentsFromRegexAsync(IStepArgumentTransformationBinding stepTransformation, string stepSnippet, CultureInfo cultureInfo)
+        private async Task<object[]> GetStepTransformationArgumentsFromRegexAsync(IStepArgumentTransformationBinding stepTransformation, string stepSnippet, CultureInfo cultureInfo, IStepArgumentTransformationBinding lastBindingUsed)
         {
             var match = stepTransformation.Regex.Match(stepSnippet);
             var argumentStrings = match.Groups.Cast<Group>().Skip(1).Select(g => g.Value).ToList();
@@ -74,7 +79,7 @@ private async Task<object[]> GetStepTransformationArgumentsFromRegexAsync(IStepA
 
             for (int i = 0; i < argumentStrings.Count; i++)
             {
-                result[i] = await ConvertAsync(argumentStrings[i], bindingParameters[i].Type, cultureInfo);
+                result[i] = await ConvertAsync(argumentStrings[i], bindingParameters[i].Type, cultureInfo, lastBindingUsed);
             }
 
             return result;

Tests/Reqnroll.RuntimeTests/Bindings/CucumberExpressions/CucumberExpressionIntegrationTests.cs

@@ -57,6 +57,11 @@ public override bool Equals(object obj)
     public override int GetHashCode() => UserName.GetHashCode();
 }
 
+public record SampleComplexUser(string Firstname, string Surname, int Age, int Height)
+{
+    public static SampleComplexUser Create(string firstname, string surname, int age, int height) => new(firstname, surname, age, height);
+}
+
 public class CucumberExpressionIntegrationTests
 {
     public class SampleBindings
@@ -100,10 +105,25 @@ public void StepDefWithCustomClassParam(SampleUser userParam)
             ExecutedParams.Add((userParam, typeof(SampleUser)));
         }
 
+        public void StepDefWithCustomComplexClassParam(SampleComplexUser userParam)
+        {
+            ExecutedParams.Add((userParam, typeof(SampleComplexUser)));
+        }
+
         public int ConvertFortyTwo()
         {
             return 42;
         }
+
+        public string ConvertToStringLowercase(string str)
+        {
+            return str.ToLower();
+        }
+
+        public int ConvertToIntPlus100(int nr)
+        {
+            return nr + 100;
+        }
     }
 
     public class TestDependencyProvider : DefaultDependencyProvider
@@ -423,4 +443,64 @@ public async void Should_match_step_with_customized_built_in_parameter_with_simp
 
         sampleBindings.ExecutedParams.Should().Contain(expectedParam);
     }
+
+    [Fact]
+    public async void Should_match_step_with_customized_built_in_parameter_without_recursion_string()
+    {
+        var expression = "there is a user {string} registered";
+        var stepText = "there is a user 'Marvin' registered";
+        var expectedParam = ("marvin", typeof(string));
+        var methodName = nameof(SampleBindings.StepDefWithStringParam);
+
+        IStepArgumentTransformationBinding transformation = new StepArgumentTransformationBinding(
+            (string)null,
+            new RuntimeBindingMethod(typeof(SampleBindings).GetMethod(nameof(SampleBindings.ConvertToStringLowercase))));
+
+        var sampleBindings = await PerformStepExecution(methodName, expression, stepText, new[] { transformation });
+
+        sampleBindings.ExecutedParams.Should().Contain(expectedParam);
+    }
+
+    [Fact]
+    public async void Should_match_step_with_customized_built_in_parameter_without_recursion_int32()
+    {
+        var expression = "I have {int} cucumbers in my belly";
+        var stepText = "I have 43 cucumbers in my belly";
+        var expectedParam = (143, typeof(int));
+        var methodName = nameof(SampleBindings.StepDefWithIntParam);
+
+        IStepArgumentTransformationBinding transformation = new StepArgumentTransformationBinding(
+            (string)null,
+            new RuntimeBindingMethod(typeof(SampleBindings).GetMethod(nameof(SampleBindings.ConvertToIntPlus100))));
+
+        var sampleBindings = await PerformStepExecution(methodName, expression, stepText, new[] { transformation });
+
+        sampleBindings.ExecutedParams.Should().Contain(expectedParam);
+    }
+
+    [Fact]
+    public async void Should_match_step_with_custom_parameter_with_additional_step_arguments()
+    {
+        var expression = "there is a {user} registered";
+        var stepText = "there is a user Marvin Smith he is 27 years old and 175 height registered";
+        var expectedParam = (new SampleComplexUser("marvin", "smith", 127, 275), typeof(SampleComplexUser));
+        var methodName = nameof(SampleBindings.StepDefWithCustomComplexClassParam);
+
+        IStepArgumentTransformationBinding transformationStringWithouthBlanks = new StepArgumentTransformationBinding(
+            (string)null,
+            new RuntimeBindingMethod(typeof(SampleBindings).GetMethod(nameof(SampleBindings.ConvertToStringLowercase))));
+
+        IStepArgumentTransformationBinding transformationIntPlus100 = new StepArgumentTransformationBinding(
+            (string)null,
+            new RuntimeBindingMethod(typeof(SampleBindings).GetMethod(nameof(SampleBindings.ConvertToIntPlus100))));
+
+        IStepArgumentTransformationBinding transformationSampleComplexUser = new StepArgumentTransformationBinding(
+            "user ([A-Za-z]+) ([A-Za-z]+) he is ([0-9]+) years old and ([0-9]+) height",
+            new RuntimeBindingMethod(typeof(SampleComplexUser).GetMethod(nameof(SampleComplexUser.Create))),
+            "user");
+
+        var sampleBindings = await PerformStepExecution(methodName, expression, stepText, new[] { transformationStringWithouthBlanks, transformationIntPlus100, transformationSampleComplexUser });
+
+        sampleBindings.ExecutedParams.Should().Contain(expectedParam);
+    }
 }