MSTEST0037 does not handle nullable arguments correctly

[stan-sz]

Describe the bug

The fixer for MSTEST0037 is not handling nullable args correctly.

Steps To Reproduce

[TestMethod]
public void TestMethod1()
{
    int? count = 3;
    Assert.AreEqual(count, new List<string>().Count);
}

Applying the fixer yields:

[TestMethod]
public void TestMethod1()
{
    int? count = 3;
    Assert.HasCount(count, new List<string>());
}

but this yields

CS1503 Argument 1: cannot convert from 'int?' to 'int'

The proper fix should be

[TestMethod]
public void TestMethod1()
{
    int? count = 3;
    Assert.IsTrue(count.HasValue); // or Assert.IsNotNull(count)
    Assert.HasCount(count.Value, new List<string>());
}

[Evangelink]

@stan-sz on the real use-cases, despite the type being nullable, are you sure to always have a value or are there cases where the value is null? I'm asking to understand if outside if fixing the rule, it could make sense to allow nullable int as type for count.

[stan-sz]

Given that the we assume the fixer is applied on code that is passing, then the value was not null. I wonder why the fixer cannot just append .Value for int??

[Youssef1313]

We can. It's a niche case though and I personally wouldn't care much if we have a bit of false negative here (as done in the linked PR).