Fix enum retriever for nullable enums and empty value (#1941)

* Added tests * fix * changelog * update changelog Co-authored-by: Andreas Willich <[email protected]>
SpecFlowOSS · May 7, 2020 · 2602a90 · 2602a90
1 parent 16580dd
commit 2602a90
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Showing 3 changed files with 49 additions and 4 deletions.
diff --git a/TechTalk.SpecFlow/Assist/ValueRetrievers/EnumValueRetriever.cs b/TechTalk.SpecFlow/Assist/ValueRetrievers/EnumValueRetriever.cs
@@ -8,6 +8,11 @@ public class EnumValueRetriever : IValueRetriever
     {
         public object GetValue(string value, Type enumType)
         {
+            if (string.IsNullOrEmpty(value) && IsNullable(enumType))
+            {
+                return null;
+            }
+
             CheckThatTheValueIsAnEnum(value, enumType);
 
             return ConvertTheStringToAnEnum(value, enumType);
@@ -20,11 +25,16 @@ public object Retrieve(KeyValuePair<string, string> keyValuePair, Type targetTyp
 
         public bool CanRetrieve(KeyValuePair<string, string> keyValuePair, Type targetType, Type propertyType)
         {
-            if (propertyType.IsGenericType && propertyType.GetGenericTypeDefinition() == typeof(Nullable<>))
+            if (IsNullable(propertyType))
                 return typeof(Enum).IsAssignableFrom(propertyType.GetGenericArguments()[0]);
             return propertyType.IsEnum;
         }
 
+        private static bool IsNullable(Type propertyType)
+        {
+            return propertyType.IsGenericType && propertyType.GetGenericTypeDefinition() == typeof(Nullable<>);
+        }
+
         private object ConvertTheStringToAnEnum(string value, Type enumType)
         {
             return StepArgumentTypeConverter.ConvertToAnEnum(GetTheEnumType(enumType), PrepareValue(value));

diff --git a/Tests/TechTalk.SpecFlow.RuntimeTests/AssistTests/SituationalTests/NullableEnumTests.cs b/Tests/TechTalk.SpecFlow.RuntimeTests/AssistTests/SituationalTests/NullableEnumTests.cs
@@ -1,10 +1,11 @@
-using Xunit;
+using System;
+using Xunit;
 using FluentAssertions;
 using TechTalk.SpecFlow.Assist;
 
 namespace TechTalk.SpecFlow.RuntimeTests.AssistTests.SituationalTests
 {
-    
+
     public class NullableEnumTests
     {
         public enum TestEnum
@@ -28,5 +29,35 @@ public void The_value_should_be_set_if_it_is_in_the_table()
             var test = table.CreateInstance<TestEntity>();
             test.TestProperty.Should().Be(TestEnum.Value2);
         }
+
+        [Fact]
+        public void The_value_should_be_NULL_if_it_is_not_filled_in_the_table()
+        {
+            var table = new Table("Field", "Value");
+            table.AddRow("TestProperty", "");
+
+            var test = table.CreateInstance<TestEntity>();
+            test.TestProperty.Should().BeNull();
+        }
+
+        [Fact]
+        public void The_value_should_be_NULL_if_it_is_not_in_the_table()
+        {
+            var table = new Table("Field", "Value");
+
+            var test = table.CreateInstance<TestEntity>();
+            test.TestProperty.Should().BeNull();
+        }
+
+        [Fact]
+        public void There_should_be_an_error_if_in_the_table_is_no_valid_Enum_value()
+        {
+            var table = new Table("Field", "Value");
+            table.AddRow("TestProperty", "NotAnEnumValue");
+
+            Action x = () => { table.CreateInstance<TestEntity>(); };
+
+            x.Should().Throw<InvalidOperationException>();
+        }
     }
-}
+}
diff --git a/changelog.txt b/changelog.txt
@@ -14,6 +14,9 @@ Changes:
 + Performance and memory improvements for `table.CreateSet` and `table.CreateInstance`
 + Changed all specflow.org hyperlinks to https (docs, generated code, packages)
 
+Fixes:
++ Empty value for nullable enum should not throw an exception
+
 
 Fixes:
 + add auto-generated comment for StyleCop to ignore the Assemblyhook files
@@ -26,6 +29,7 @@ Fixes:
 + Revert "Replace NUnit.Framework.DescriptionAttribute to TestName in NUnit generator #1225" because of problems with the NUnit Test Adapter
 + Remove files with invalid characters from the FeatureFiles list (provided by msbuild)
 
+
 Features:
 + Created VerifyAllColumnsBound check for `table.CreateSet` and `table.CreateInstance`