Why is this an issue?

This rule addresses the issue of incomplete assertions that can occur when using certain test frameworks. Incomplete assertions can lead to tests that do not effectively verify anything. The rule enforces the use of complete assertions in specific cases, namely:

string actual = "Using Fluent Assertions";
actual.Should(); // Noncompliant

string actual = "Using NFluent";
Check.That(actual); // Noncompliant

command.Received(); // Noncompliant

In such cases, what is intended to be a test doesn’t actually verify anything.

How to fix it in Fluent Assertions

Fluent Assertions provides an interface for writing assertions, and it is important to ensure that Should() is properly used in conjunction with an assertion method.

Code examples

Noncompliant code example

string actual = "Hello World!";
actual.Should(); // Noncompliant

Compliant solution

string actual = "Hello World!";
actual.Should().Contain("Hello");

How to fix it in NFluent

NFluent offers a syntax for assertions, and it’s important to follow Check.That() with an assertion method to complete the assertion.

Code examples

Noncompliant code example

string actual = "Hello World!";
Check.That(actual); // Noncompliant

Compliant solution

string actual = "Hello World!";
Check.That(actual).Contains("Hello");

How to fix it in NSubstitute

NSubstitute is a mocking framework, and Received() is used to verify that a specific method has been called. However, invoking a method on the mock after calling Received() is necessary to ensure the complete assertion.

Code examples

Noncompliant code example

command.Received(); // Noncompliant

Compliant solution

command.Received().Execute();

Resources

Documentation