NUnit2020

Incompatible types for SameAs constraint

Topic	Value
Id	NUnit2020
Severity	Error
Enabled	True
Category	Assertion
Code	SameAsIncompatibleTypesAnalyzer

Description

The SameAs constraint always fails because the actual and expected values have mutually exclusive types.

Motivation

class Foo { }
class Bar { }

var foo = new Foo();
var bar = new Bar();

Assert.That(foo, Is.SameAs(bar));

There is no way that the same instance can be of type Foo and type Bar, therefore such assertion will always fail.

How to fix violations

Fix your assertion (i.e. fix actual or expected value, or choose another constraint)

Configure severity

Via ruleset file

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

Via .editorconfig file

# NUnit2020: Incompatible types for SameAs constraint
dotnet_diagnostic.NUnit2020.severity = chosenSeverity

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

Via #pragma directive

#pragma warning disable NUnit2020 // Incompatible types for SameAs constraint
Code violating the rule here
#pragma warning restore NUnit2020 // Incompatible types for SameAs constraint

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

#pragma warning disable NUnit2020 // Incompatible types for SameAs constraint

Via attribute [SuppressMessage]

[System.Diagnostics.CodeAnalysis.SuppressMessage("Assertion",
    "NUnit2020:Incompatible types for SameAs constraint",
    Justification = "Reason...")]