NUnit1018

The number of parameters provided by the TestCaseSource does not match the number of parameters in the target method

Topic	Value
Id	NUnit1018
Severity	Error
Enabled	True
Category	Structure
Code	TestCaseSourceUsesStringAnalyzer

Description

The number of parameters provided by the TestCaseSource must match the number of parameters in the target method.

Motivation

To prevent tests that will fail at runtime due to improper construction.

How to fix violations

Example Violation

public class MyTestClass
{
    [TestCaseSource(nameof(Strings), new object[] { "Testing" })]
    public void StringTest(string input)
    {
        Assert.That(input, Is.Not.Null);
    }

    static IEnumerable<string> Strings(string first, string second)
    {
        yield return first;
        yield return second;
    }
}

Explanation

In the sample above, the method Strings expects two arguments, but the TestCaseSource only supplies one argument.

Fix

Either change Strings to only expect one argument or supply both from the TestCaseSource:

public class MyTestClass
{
    [TestCaseSource(nameof(Strings), new object[] { "Testing", "TestCaseSource" })]
    public void StringTest(string input)
    {
        Assert.That(input, Is.Not.Null);
    }

    static IEnumerable<string> Strings(string first, string second)
    {
        yield return first;
        yield return second;
    }
}

Configure severity

Via ruleset file

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

Via .editorconfig file

# NUnit1018: The number of parameters provided by the TestCaseSource does not match the number of parameters in the target method
dotnet_diagnostic.NUnit1018.severity = chosenSeverity

where chosenSeverity can be one of none, silent, suggestion, warning, or error.

Via #pragma directive

#pragma warning disable NUnit1018 // The number of parameters provided by the TestCaseSource does not match the number of parameters in the target method
Code violating the rule here
#pragma warning restore NUnit1018 // The number of parameters provided by the TestCaseSource does not match the number of parameters in the target method

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

#pragma warning disable NUnit1018 // The number of parameters provided by the TestCaseSource does not match the number of parameters in the target method

Via attribute [SuppressMessage]

[System.Diagnostics.CodeAnalysis.SuppressMessage("Structure",
    "NUnit1018:The number of parameters provided by the TestCaseSource does not match the number of parameters in the target method",
    Justification = "Reason...")]