NUnit2009

NUnit2009

Same value provided as actual and expected argument.

Topic	Value
Id	NUnit2009
Severity	Warning
Enabled	True
Category	Structure
Code	SameActualExpectedValueAnalyzer

Description

The same value has been provided as both actual and expected argument. This indicates a coding error.

Motivation

To bring developers' attention to a situation in which their code may not be operating as expected and their test may not be testing what they expect.

How to fix violations

Sample Violation

[Test]
public void Nunit2009SampleTest()
{
    var x = 1;
    Assert.That(x, Is.EqualTo(x));
}

Explanation

In the above example, the test will always be correct, because we're comparing the same value. That is to say, we're not actually testing anything.

Fix

Ensure the expected and actual values come from different places.

[Test]
public void Nunit2009SampleTest()
{
    var x = 1;
    Assert.That(x, Is.EqualTo(1));
}

Configure severity

Via ruleset file.

Configure the severity per project, for more info see MSDN.

Via #pragma directive.

#pragma warning disable NUnit2009 // Same value provided as actual and expected argument.
Code violating the rule here
#pragma warning restore NUnit2009 // Same value provided as actual and expected argument.

Or put this at the top of the file to disable all instances.

#pragma warning disable NUnit2009 // Same value provided as actual and expected argument.

Via attribute [SuppressMessage].

[System.Diagnostics.CodeAnalysis.SuppressMessage("Structure", 
    "NUnit2009:Same value provided as actual and expected argument.",
    Justification = "Reason...")]