NUnit2011

NUnit2011

Use ContainsConstraint.

Topic	Value
Id	NUnit2011
Severity	Info
Enabled	True
Category	Assertion
Code	StringConstraintUsageAnalyzer

Description

Using constraints instead of boolean methods will lead to better assertion messages in case of failure.

Motivation

Using Does.Contain (or Does.Not.Contain) constraint will lead to better assertion messages in case of failure, so this analyzer marks all usages of string Contains method where it is possible to replace with Does.Contain constraint.

[Test]
public void Test()
{
    string actual = "...";
    string expected = "...";
    Assert.True(actual.Contains(expected));
}

How to fix violations

The analyzer comes with a code fix that will replace Assert.True(actual.Contains(expected)) with Assert.That(actual, Does.Contain(expected)). So the code block above will be changed into

[Test]
public void Test()
{
    string actual = "...";
    string expected = "...";
    Assert.That(actual, Does.Contain(expected));
}

Configure severity

Via ruleset file.

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

Via #pragma directive.

#pragma warning disable NUnit2011 // Use ContainsConstraint.
Code violating the rule here
#pragma warning restore NUnit2011 // Use ContainsConstraint.

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

#pragma warning disable NUnit2011 // Use ContainsConstraint.

Via attribute [SuppressMessage].

[System.Diagnostics.CodeAnalysis.SuppressMessage("Assertion", 
    "NUnit2011:Use ContainsConstraint.",
    Justification = "Reason...")]