Microsoft Visual Studio Beginner: Unit Testing

Name: Microsoft Visual Studio Beginner: Unit Testing
Author: Gerald Eckert

Enhance code quality by writing effective unit tests

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Course: On-Demand

Hello, my name is Gerald. In these lessons, you will learn how to perform unit testing in Visual Studio, we will be using the MS Test framework that is included by default with Visual Studio. In this lesson, I will show you how to add a unit test project and write your first unit test. Let's take a look at our code first. Before we add some unit tests. Here in Visual Studio I have a class library opened with some extension methods for C#. We're going to test the integer extensions class and specifically the is even function. This is a C# extension method that tests the evenness of an integer, and it will return a true or false value depending on if the integer is even. So now we've learned the code, let's add a unit test project. To add a unit test project, move to your Solution Explorer, right click on your solution node and then select add, new project. So now we have the new Project Wizard screen. We're gonna search for unit test templates. Here what you may see different types of unit tests. We can see X unit test project using the X unit framework. We have a MS Test project for .Net Core and the unit test project for .Net Framework. We're gonna select the unit test project for the .Net Framework. Now we'll give our unit test project a name, I will call this unit tests. And then I will click create to add it to our solution. You can see here Visual Studio opened the first default file. I'm gonna close all these, we can look at the Solution Explorer. You can see in our Solution Explorer here, we now have two projects. We have our original class library, and a new unit test project. So before we can write unit tests, we need to reference the code that we're going to be testing. So we need to add a reference to the unit test project by right clicking on the references node and selecting add reference. This will open the Reference Manager and we are going to reference a project within our solution. Here it is the extension library. So I will check that and click okay. This will add a reference to our unit tests for the extension library project. So we can use that code. So now we have a reference added and we are ready to write unit tests. By default Visual Studio adds an example unit test class. Let's open that. First I'm going to rename our class and our test method so it lines up with the class and test method that we're going to be unit testing which is the integer extensions class and the is even function. So I'm gonna rename both of these so they line up correctly. So I've renamed the test class and the test method to line up with the code we're testing. The next important thing to take note of are these attributes on our class and their method. These attributes tell Visual Studio that these are not regular code but these are test classes and they will be picked up in the test runner and ran as unit tests. So every unit test we write will be decorated with this test method attribute. Now let's write our first unit test to test that is even function. To do that, we're going to use asserts. We'll declare a test variable and then use the assert statement to test our test variable. So I'm gonna write our first test variable called test one and give it a integer value. So now we have a test variable and it's assigned a value of two. Now I will use the assert statement and call the is even function to test the function. So now I've written the assert statement and I am calling that is even function. I need to include the name space, that's why there's an error. And what this will do is say assert that this statement inside of the parenthesis is true. And inside of here, we are calling or is even function, that's the function we are testing. So now the unit test is completely written and we are ready to run it, to run your unit tests move to the Solution Explorer, right click on your unit test project and select run tests. What this will do is open the Test Explorer and start running your unit tests. You see a tree view here organized by projects, name space, the class and then we can see our individual unit tests. And all these green check marks mean that the unit test has passed and here in the right hand pane we can see some information about that specific unit test. We can see the source and how long that unit test took to run. Let's go add another unit test so we can see what a failed unit test looks like. So I'm gonna add a new test method here and purposely make it fail. So now I've added a second unit test called is even test two and I've set the variable to three. And that will cause this statement to fail because three is definitely not even. And we're asserting that a statement will be true. So I'm gonna come over to our Test Explorer tab and I'm gonna select the run all tests in view. This will run all of our unit tests again and we can see one of them fail. So here our tests have run and we can see is even test two has failed and we see an error message. So that is the basic framework for writing unit tests and testing them using the test runner. So now you know how to add a unit test project to your solution, write unit tests, and use the Test Explorer to run your unit tests. Stay tuned for the next lesson where we will cover using the MS Test framework to set up your unit test projects.

Beginner Provider : Gerald Eckert 4 Lessons · 27m in Arabic, German, English, Spanish, French, Portuguese, Chinese

Course Description

Unit testing is critical to ensuring you have written quality code. If your code breaks often, constantly needs to be refactored, or is very old, unit testing is often the solution to these problems. With unit testing you can test your code for many of the scenarios it will encounter. This allows you to quickly find points of failure and weaknesses, fixing them before they create bugs. To do this, we will look at setting up unit test classes and writing unit tests to test the functions. We will explore purposefully failing our unit tests and reviewing error messages. With unit tests set up correctly, you will generate fewer regressions, fewer bug reports, and reduce technical debt.

In Unit Testing, you will learn how to create your first unit test and streamline unit testing with MS Test attributes. We will also discuss project settings and learn test driven development within Visual Studio.

What You'll Learn

Create your first unit test in Microsoft Visual Studio
Set up unit test classes and unit test projects using MSTest attributes
Write unit tests to test your functions, including purposefully failing tests and reviewing error messages
Apply test driven development to new projects within Visual Studio
Improve code quality by unit testing
Streamline unit testing by using attributes and configuring testing setup procedures

Key Takeaways

Unit testing helps you find points of failure and weaknesses in your code so you can fix them before they create bugs.
Unit testing lets you test your code for many of the scenarios it will encounter.
With unit tests set up correctly, you generate fewer regressions, fewer bug reports, and reduce technical debt.
MSTest attributes and testing setup procedures help streamline the unit testing process.
Unit testing is often the solution when code breaks often, constantly needs refactoring, or is very old.

Frequently Asked Questions

What will I learn in this course?

You will learn how to create your first unit test, streamline unit testing with MSTest attributes, configure project settings, and apply test driven development within Visual Studio.

How is the course structured?

The course includes four lessons: Creating Your First Unit Test; MSTest Attributes and Setting Up Unit Test Projects - Part 1; MSTest Attributes and Setting Up Unit Test Projects - Part 2; and Test Driven Development With Visual Studio.

What skills will I gain from this course?

You will build skills in Code Testing, MSTest, Software Testing, Unit Test-Driven Development, Unit Testing, and Vstest.

Why is unit testing important?

Unit testing is critical to ensuring you have written quality code; it lets you test your code for many scenarios it will encounter, quickly find points of failure and weaknesses, and fix them before they create bugs, resulting in fewer regressions, fewer bug reports, and reduced technical debt.

Does the course cover what happens when tests fail?

Yes. The course explores purposefully failing your unit tests and reviewing the resulting error messages.