NUnit2040

Non-reference types for SameAs constraint

Topic	Value
Id	NUnit2040
Severity	Error
Enabled	True
Category	Assertion
Code	SameAsOnValueTypesAnalyzer

Description

The SameAs constraint always fails on value types as the actual and the expected value cannot be the same reference.

Motivation

var expected = Guid.Empty;
var actual = expected;

Assert.That(actual, Is.SameAs(expected));

As Guid is a struct, actual will be a copy of expected but not have the same reference.

How to fix violations

Replace Is.SameAs with Is.EqualTo.

var expected = Guid.Empty;
var actual = expected;

Assert.That(actual, Is.EqualTo(expected));

Configure severity

Via ruleset file

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

Via .editorconfig file

# NUnit2040: Non-reference types for SameAs constraint
dotnet_diagnostic.NUnit2040.severity = chosenSeverity

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

Via #pragma directive

#pragma warning disable NUnit2040 // Non-reference types for SameAs constraint
Code violating the rule here
#pragma warning restore NUnit2040 // Non-reference types for SameAs constraint

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

#pragma warning disable NUnit2040 // Non-reference types for SameAs constraint

Via attribute [SuppressMessage]

[System.Diagnostics.CodeAnalysis.SuppressMessage("Assertion",
    "NUnit2040:Non-reference types for SameAs constraint",
    Justification = "Reason...")]