Using an interface in dynamic data causes a de-/serialization exception #908
Description
Description
Upgrading MSTest.TestAdapter from version 2.2.3 to 2.2.5 causes this error.
To test a extension method I am providing some dynamic data as IEnumerable which now provides an exception.
Steps to reproduce
// Test code which produces the error
public static IEnumerable<Object[]> AddTestCases {
get {
var sut = new Collection<String>();
var expected = new Collection<String>();
yield return new Object[] { sut, Enumerable.Empty<String>(), expected };
sut = new Collection<String>() { "1" };
expected = new Collection<String>() { "1" };
yield return new Object[] { sut, Enumerable.Empty<String>(), expected };
sut = new Collection<String>();
expected = new Collection<String>() { "1" };
yield return new Object[] { sut, new[] { "1" }, expected };
sut = new Collection<String>() { "1", "a", "b" };
expected = new Collection<String>() { "1", "a", "b", "z", "j" };
yield return new Object[] { sut, new[] { "z", "j" }, expected };
}
}
[DataTestMethod]
[DynamicData(nameof(AddTestCases))]
public void Add_ShouldAddTheExpectedValues(Collection<String> systemUnderTest, IEnumerable<String> itemsToAdd, Collection<String> expected) {
// The acutal tested method is irrelevant. Executing this empty tests provokes the error
}Expected behavior
4 test cases are executed
Actual behavior
Only two test cases are executed and then the following exception is logged from dotnet test.
Failed Add_ShouldAddTheExpectedValues (System.Collections.ObjectModel.Collection`1[System.String],System.Linq.EmptyPartition`1[System.String],System.Collections.ObjectModel.Collection`1[System.String])
Error Message:
Value cannot be null. (Parameter 'con')
Stack Trace:
at System.Reflection.Emit.DynamicILGenerator.Emit(OpCode opcode, ConstructorInfo con)
at System.Runtime.Serialization.CodeGenerator.New(ConstructorInfo constructorInfo)
at System.Runtime.Serialization.Json.JsonFormatReaderGenerator.CriticalHelper.ReadCollection(CollectionDataContract collectionContract)
at System.Runtime.Serialization.Json.JsonFormatReaderGenerator.CriticalHelper.GenerateCollectionReader(CollectionDataContract collectionContract)
at System.Runtime.Serialization.Json.JsonCollectionDataContract.get_JsonFormatReaderDelegate()
at System.Runtime.Serialization.Json.JsonCollectionDataContract.ReadJsonValueCore(XmlReaderDelegator jsonReader, XmlObjectSerializerReadContextComplexJson context)
at System.Runtime.Serialization.Json.JsonDataContract.ReadJsonValue(XmlReaderDelegator jsonReader, XmlObjectSerializerReadContextComplexJson context)
at System.Runtime.Serialization.Json.XmlObjectSerializerReadContextComplexJson.ReadDataContractValue(DataContract dataContract, XmlReaderDelegator reader)
at System.Runtime.Serialization.XmlObjectSerializerReadContext.InternalDeserialize(XmlReaderDelegator reader, String name, String ns, Type declaredType, DataContract& dataContract)
at System.Runtime.Serialization.XmlObjectSerializerReadContextComplex.InternalDeserialize(XmlReaderDelegator xmlReader, Type declaredType, DataContract dataContract, String name, String ns)
at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.InternalReadObject(XmlReaderDelegator xmlReader, Boolean verifyObjectName)
at System.Runtime.Serialization.XmlObjectSerializer.InternalReadObject(XmlReaderDelegator reader, Boolean verifyObjectName, DataContractResolver dataContractResolver) at System.Runtime.Serialization.XmlObjectSerializer.ReadObjectHandleExceptions(XmlReaderDelegator reader, Boolean verifyObjectName, DataContractResolver dataContractResolver)
at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.ReadObject(XmlDictionaryReader reader)
at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.ReadObject(Stream stream)
Failed Add_ShouldAddTheExpectedValues (System.Collections.ObjectModel.Collection`1[System.String],System.Linq.EmptyPartition`1[System.String],System.Collections.ObjectModel.Collection`1[System.String])
Error Message:
Value cannot be null. (Parameter 'con')
Stack Trace:
at System.Reflection.Emit.DynamicILGenerator.Emit(OpCode opcode, ConstructorInfo con)
at System.Runtime.Serialization.CodeGenerator.New(ConstructorInfo constructorInfo)
at System.Runtime.Serialization.Json.JsonFormatReaderGenerator.CriticalHelper.ReadCollection(CollectionDataContract collectionContract)
at System.Runtime.Serialization.Json.JsonFormatReaderGenerator.CriticalHelper.GenerateCollectionReader(CollectionDataContract collectionContract)
at System.Runtime.Serialization.Json.JsonCollectionDataContract.get_JsonFormatReaderDelegate()
at System.Runtime.Serialization.Json.JsonCollectionDataContract.ReadJsonValueCore(XmlReaderDelegator jsonReader, XmlObjectSerializerReadContextComplexJson context)
at System.Runtime.Serialization.Json.JsonDataContract.ReadJsonValue(XmlReaderDelegator jsonReader, XmlObjectSerializerReadContextComplexJson context)
at System.Runtime.Serialization.Json.XmlObjectSerializerReadContextComplexJson.ReadDataContractValue(DataContract dataContract, XmlReaderDelegator reader)
at System.Runtime.Serialization.XmlObjectSerializerReadContext.InternalDeserialize(XmlReaderDelegator reader, String name, String ns, Type declaredType, DataContract& dataContract)
at System.Runtime.Serialization.XmlObjectSerializerReadContextComplex.InternalDeserialize(XmlReaderDelegator xmlReader, Type declaredType, DataContract dataContract, String name, String ns)
at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.InternalReadObject(XmlReaderDelegator xmlReader, Boolean verifyObjectName)
at System.Runtime.Serialization.XmlObjectSerializer.InternalReadObject(XmlReaderDelegator reader, Boolean verifyObjectName, DataContractResolver dataContractResolver) at System.Runtime.Serialization.XmlObjectSerializer.ReadObjectHandleExceptions(XmlReaderDelegator reader, Boolean verifyObjectName, DataContractResolver dataContractResolver)
at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.ReadObject(XmlDictionaryReader reader)
at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.ReadObject(Stream stream)
Environment
Operating system: Windows 10 latest patches
Build version of vstest.console: Microsoft (R) Test Execution Command Line Tool Version 16.10.0
Package version of MSTest framework and adapter: Both 2.2.5 but only updating the Adapater to 2.2.5 causes this issues
Other installed packages and their versions on the test project:
- FluentAssertions 5.10.3
- Microsoft.CodeAnalysis.NetAnalyzers 5.0.3
- Microsoft.NET.Test.Sdk 16.10.0
- coverlet.collector 3.0.3
Note
A workaround is replacing Enumerable.Empty<String>() with Array.Empty<String>().