I am trying to write a custom TestMethodAttribute that allows to annotate a test with some meta information that should be output in the .trx file generated by the test runner of MSTest.

I therefore implemented the following attribute:

public class CustomTestMethodAttribute : TestMethodAttribute
{
    
    private string _meta1;
    private string[] _meta2;
    
    public CustomTestMethodAttribute(string meta1, string[] meta2, string? displayName = null) : base(displayName)
    {
        _meta1 = meta1;
        _meta2 = meta2;
    }

    public override TestResult[] Execute(ITestMethod testMethod)
    {
        MethodInfo methodInfo = testMethod.MethodInfo;

        Dictionary<string, object> metaProperties = new()
        {
            {
                "task", new Dictionary<string, object>
                {
                    { "className", testMethod.TestClassName },
                    { "method", methodInfo.Name },
                    { "meta1", _meta1 },
                    { "meta2", _meta2 }
                }
            }
        };

        // that is the line that doesn't work
        testContext.WriteLine($"META_INFORMATION={JsonSerializer.Serialize(metaProperties)}");

        return new TestResult[] { testMethod.Invoke(null) };
    }
    
}

It would allow me to annotate a test method like this:

[CustomTestMethod(meta1: "12345", meta2:new []{"12345", "23456"})]
public void MyTestMethod()
{
    ...
}

My question is: what’s the easiest way to access the TestContext in the Execute method of the CustomTestMethodAttribute. TestContext is injected (by MSTest?) into my test class via

[TestClass]
class Test1
{
    public TestContext TestContext { get; set; }

    ...
}

and is therefore accessible within the test method via TestContext.

If accessing TestContext is not possible within the attribute – how can I use something like testContext.WriteLine() in my attribute?