NUnit1023

The target method expects parameters which cannot be supplied by the ValueSource

Topic	Value
Id	NUnit1023
Severity	Error
Enabled	True
Category	Structure
Code	ValueSourceUsageAnalyzer

Description

The target method expects parameters which cannot be supplied by the ValueSource.

Motivation

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

How to fix violations

Example Violation

public class MyTestClass
{
    [Test]
    public void StringTest([ValueSource(nameof(Strings))] 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 ValueSource cannot supply arguments.

Fix

Change Strings so that it does not expect any arguments:

public class MyTestClass
{
    [Test]
    public void StringTest([ValueSource(nameof(Strings))] string input)
    {
        Assert.That(input, Is.Not.Null);
    }

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

Configure severity

Via ruleset file

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

Via .editorconfig file

# NUnit1023: The target method expects parameters which cannot be supplied by the ValueSource
dotnet_diagnostic.NUnit1023.severity = chosenSeverity

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

Via #pragma directive

#pragma warning disable NUnit1023 // The target method expects parameters which cannot be supplied by the ValueSource
Code violating the rule here
#pragma warning restore NUnit1023 // The target method expects parameters which cannot be supplied by the ValueSource

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

#pragma warning disable NUnit1023 // The target method expects parameters which cannot be supplied by the ValueSource

Via attribute [SuppressMessage]

[System.Diagnostics.CodeAnalysis.SuppressMessage("Structure",
    "NUnit1023:The target method expects parameters which cannot be supplied by the ValueSource",
    Justification = "Reason...")]