MSTest v2.2.4 not working for some data tests: System.ArgumentException: Object of type 'System.Int32' cannot be converted to type 'System.UInt32

Description

After upgrading to MSTest 2.2.4 I’m getting System.ArgumentException for data tests with some data types

Steps to reproduce

• MSTest 2.2.4
• Create this test:

[TestMethod]
[DataRow(0U)]
[DataRow(1U)]
[DataRow(2U)]
public async Task TestWithUint(uint index)
{
    //ellided
}

Expected behavior

• Test to run without exceptions as prior to v2.2.4

Actual behavior

• Getting the exception:

    System.ArgumentException: Object of type 'System.Int32' cannot be converted to type 'System.UInt32'.
  Stack Trace: 
    RuntimeType.TryChangeType(Object value, Binder binder, CultureInfo culture, Boolean needsSpecialCast)
    RuntimeType.CheckValue(Object value, Binder binder, CultureInfo culture, BindingFlags invokeAttr)
    MethodBase.CheckArguments(Object[] parameters, Binder binder, BindingFlags invokeAttr, CultureInfo culture, Signature sig)
    RuntimeMethodInfo.InvokeArgumentsCheck(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
    RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
    MethodBase.Invoke(Object obj, Object[] parameters)
    ThreadOperations.ExecuteWithAbortSafety(Action action)

Environment

Windows 21H1 build 19043.1023 VS 16.9.6

[paul-michalik]

After 2.2.4, as long as the values in data source are serializable, every row for the specific test case is considered a separate test case. If our assumptions break parallel test runs that’s a regression. Is it possible for you to share a quick repro with us?

@Haplois I will share a complete project when I have more time, but in general, consider a test case like this:

[
  DataTestMethod,
  DynamicData(dynamicDataSourceName: nameof(GetData), DynamicDataSourceType.Method)
]
public async Task Create_Tasks_Requests_From_Invalid_Tasks_Definitions_Should_Return_BadRequest_Errors(Events.APIGatewayProxyRequest request, Requests.CreateTaskCommand.Arguments arguments)
{
    // test code
}

with GetData similar to this:

public static IEnumerable<object[]> GetData() =>
 new [] {
    new [] object {
         // initialize pair of objects
    },
    new [] object {
         // initialize pair of objects
    },
 }

If I run such test cases in parallel (method level parallelism) then I see all kinds of exception suggesting that the the test framework attempts to pull the enumerable on different threads. I have plenty of data sources structured like this:

public static IEnumerable<object[]> GetData()
{
    yield new InputData {
       // ...
    };

    yield new InputData {
       // ...
    };

    // etc.
}

These obviously can’t be pulled in parallel either.

[Haplois]

@paul-michalik thanks for reporting this. We’ll we working on fixing this. You can track it here #906.