NUnit1020

The TestCaseSource provides parameters to a source - field or property - that expects no parameters

Topic	Value
Id	NUnit1020
Severity	Error
Enabled	True
Category	Structure
Code	TestCaseSourceUsesStringAnalyzer

Description

The TestCaseSource must not provide any parameters when the source is a field or a property.

Motivation

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

How to fix violations

Example Violation

public class MyTestClass
{
    [TestCaseSource(nameof(DivideCases), new object[] { "Testing" })]
    public void DivideTest(int n, int d, int q)
    {
        Assert.AreEqual(q, n / d);
    }

    static object[] DivideCases =
    {
        new object[] { 12, 3, 4 },
        new object[] { 12, 2, 6 },
        new object[] { 12, 4, 3 }
    };
}

Explanation

In the sample above, DivideCases is a field, and as such does not accept any arguments, so the TestCaseSource should not supply any parameters.

Fix

Either remove the parameter from TestCaseSource or change the field into a method.:

public class MyTestClass
{
    [TestCaseSource(nameof(DivideCases), new object[] { "Testing" })]
    public void DivideTest(int n, int d, int q)
    {
        Assert.AreEqual(q, n / d);
    }

    static object[] DivideCases(string input)
    {
        return new object[]
        {
            new object[] { 12, 3, 4 },
            new object[] { 12, 2, 6 },
            new object[] { 12, 4, 3 }
        };
    }
}

Configure severity

Via ruleset file

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

Via .editorconfig file

# NUnit1020: The TestCaseSource provides parameters to a source - field or property - that expects no parameters
dotnet_diagnostic.NUnit1020.severity = chosenSeverity

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

Via #pragma directive

#pragma warning disable NUnit1020 // The TestCaseSource provides parameters to a source - field or property - that expects no parameters
Code violating the rule here
#pragma warning restore NUnit1020 // The TestCaseSource provides parameters to a source - field or property - that expects no parameters

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

#pragma warning disable NUnit1020 // The TestCaseSource provides parameters to a source - field or property - that expects no parameters

Via attribute [SuppressMessage]

[System.Diagnostics.CodeAnalysis.SuppressMessage("Structure",
    "NUnit1020:The TestCaseSource provides parameters to a source - field or property - that expects no parameters",
    Justification = "Reason...")]