Write Unit Tests (NUnit) - (ASP.NET Core Unit Testing)

Unit testing is an essential part of software development that ensures the quality and reliability of the code. NUnit is a popular .NET unit testing framework that allows developers to write and execute unit tests in a structured and organized way. In this page, we will discuss how to write and execute unit tests using NUnit in an ASP.NET Core application.

Syntax

Here is the basic syntax of an NUnit test:

[TestFixture]
public class MyTest
{
    [TestCase]
    public void TestMethod()
    {
        // Test code
    }
}

The TestFixture attribute marks the class as a test fixture, and the TestCase attribute marks each test method.

Example

Let's create a simple Calculator class and write some unit tests for it.

public class Calculator
{
    public int Add(int num1, int num2)
    {
        return num1 + num2;
    }

    public int Subtract(int num1, int num2)
    {
        return num1 - num2;
    }
}

Next, let's create an NUnit test fixture for the Calculator class. In this example, we will define two test methods, one for each operation.

[TestFixture]
public class CalculatorTests
{
    Calculator calc;

    [SetUp]
    public void Setup()
    {
        calc = new Calculator();
    }

    [TestCase]
    public void AddMethod_ReturnsCorrectResult()
    {
        int result = calc.Add(2, 3);
        Assert.AreEqual(result, 5);
    }

    [TestCase]
    public void SubtractMethod_ReturnsCorrectResult()
    {
        int result = calc.Subtract(10, 5);
        Assert.AreEqual(result, 5);
    }
}

In this example, we're using the SetUp attribute to create a new instance of the Calculator class before each test case is run. The TestCase attribute is used to mark each test method. Within each test method, we're using the Assert class to verify that the calculated result is what we expect.

Output

When you run the tests, NUnit will output the results to the test console and generate an XML file with the results.

Explanation

Unit testing helps to ensure that your code works as expected and that changes to your code don't break existing functionality. NUnit is a popular .NET unit testing framework that allows you to write and execute unit tests in a structured and organized way.

In the example above, we created a Calculator class and defined two methods for adding and subtracting values. We then created a test fixture using NUnit and defined two test methods, one for each operation. Finally, we executed the tests and used the Assert class to verify that the calculated values match our expected values.

Use

Unit testing is a crucial part of developing software that ensures that your code is behaving as desired and expected. By using a framework like NUnit to write and execute your unit tests, you can ensure that changes to your code do not cause unexpected behavior and that your software is always of the highest quality.

Important Points

• NUnit is a popular .NET unit testing framework that allows developers to write and execute unit tests in a structured and organized way.
• Unit testing is a crucial part of developing software that ensures that your code is behaving as desired and expected.
• Use the SetUp attribute to create a new instance of a class before each test case is run.
• Use the TestCase attribute to mark each test method.
• Use the Assert class to verify that your calculated values match your expected values.

Summary

In this page, we discussed how to write and execute unit tests using NUnit in an ASP.NET Core application. We covered the syntax, example, output, explanation, use, important points, and summary of writing unit tests using NUnit in an ASP.NET Core application. By writing and executing unit tests in a structured and organized way, we can ensure the quality and reliability of the code we produce.