Code inspection: NUnit. Duplicate values.

This inspection reports duplicate entries inside NUnit value-providing attributes such as [Values(...)] when those duplicates only create repeated test cases. Using the same value more than once usually does not increase test coverage, but it does make the test matrix larger and noisier.

Duplicate values produce unnecessary duplicate tests, which slows execution and makes the input set harder to understand.

Example

                [Test]
                public void Calculates(
                    [Values(1, 1, 2)] int x,
                    [Values("+", "-", "+")] string op)
                {
                }
            

                [Test]
                public void Calculates(
                    [Values(1, 2)] int x,
                    [Values("+", "-")] string op)
                {
                }
            

31 March 2026