NUnit retry dynamic attribute

Question

Hello I want to pass the number of retries dynamically from app.config value.

The app.config has the following line:

Answer 1

A bit of work around, but you can use TestCaseSource attribute to create data driven test that will run numberOfRetries times

[Test, TestCaseSource("GetNum")]
public void Test(int testNum)
{
}

private IEnumerable GetNum
{
    get
    {
        int numberOfRetries = int.Parse(ConfigurationManager.AppSettings["retryTest"]);
        for (int i = 1; i <= numberOfRetries; ++i)
        {
            yield return new TestCaseData(i);
        }
    }
}

In test explorer you will see Test(1), Test(2), Test(3).

Answer 2

While I am not fully aware of the RetryAttribute. One possible way of achieving the desired functionality would be to extend its current functionality.

/// <summary>
/// RetryDynamicAttribute may be applied to test case in order
/// to run it multiple times based on app setting.
/// </summary>
[AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = false)]
public class RetryDynamicAttribute : RetryAttribute {
    private const int DEFAULT_TRIES = 1;
    static Lazy<int> numberOfRetries = new Lazy<int>(() => {
        int count = 0;
        return int.TryParse(ConfigurationManager.AppSettings["retryTest"], out count) ? count : DEFAULT_TRIES;
    });

    public RetryDynamicAttribute() :
        base(numberOfRetries.Value) {
    }
}

And then apply the custom attribute.

[Test]
[RetryDynamic]
public void Test() {
    //.... 
}