When I run my tests in a terminal window or in Visual Studio for Mac, the. Green but I didn't know which lines of code or which classes were covered by the unit testing. Dotnet test NBAStats.Core.Test.csproj Starting test execution, please wait. Analyzing 30 classes 2019-10-20T15:31:27: Writing report file. Mar 18, 2017 The easiest way to get started is to install the NUnit Templates extension for Visual Studio.It will add project templates for the various Xamarin platforms. For more general information, see Testing Xamarin Projects using NUnit 3. Getting started.
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Check that your code is working as expected by creating and running unit tests. It's called unit testing because you break down the functionality of your program into discrete testable behaviors that you can test as individual units. Visual Studio Test Explorer provides a flexible and efficient way to run your unit tests and view their results in Visual Studio. Visual Studio installs the Microsoft unit testing frameworks for managed and native code. Use a unit testing framework to create unit tests, run them, and report the results of these tests. Rerun unit tests when you make changes to test that your code is still working correctly. Visual Studio Enterprise can do this automatically with Live Unit Testing, which detects tests affected by your code changes and runs them in the background as you type.
Unit testing has the greatest effect on the quality of your code when it's an integral part of your software development workflow. As soon as you write a function or other block of application code, create unit tests that verify the behavior of the code in response to standard, boundary, and incorrect cases of input data, and that check any explicit or implicit assumptions made by the code. With test driven development, you create the unit tests before you write the code, so you use the unit tests as both design documentation and functional specifications.
You can quickly generate test projects and test methods from your code, or manually create the tests as you need them. When you use IntelliTest to explore your .NET code, you can generate test data and a suite of unit tests. For every statement in the code, a test input is generated that will execute that statement. Find out how to generate unit tests for your code.
Test Explorer can also run third-party and open source unit test frameworks that have implemented Test Explorer add-on interfaces. You can add many of these frameworks through the Visual Studio Extension Manager and the Visual Studio gallery. For more information, see Install third-party unit test frameworks.
Get started
For an introduction to unit testing that takes you directly into coding, see one of these topics:
The MyBank solution example
In this article, we use the development of a fictional application called
MyBank as an example. You don't need the actual code to follow the explanations in this topic. Test methods are written in C# and presented by using the Microsoft Unit Testing Framework for Managed Code. However, the concepts are easily transferred to other languages and frameworks.
Our first attempt at a design for the
MyBank application includes an accounts component that represents an individual account and its transactions with the bank, and a database component that represents the functionality to aggregate and manage the individual accounts.
We create a
MyBank solution that contains two projects:
Our first attempt at designing the
Accounts project contains a class to hold basic information about an account, an interface that specifies the common functionality of any type of account, like depositing and withdrawing assets from the account, and a class derived from the interface that represents a checking account. We begin the Accounts projects by creating the following source files:
We know from experience that one thing a withdrawal from a checking account must do is to make sure that the amount withdrawn is less than the account balance. So we override the
IAccount.Withdraw method in CheckingAccount with a method that checks for this condition. The method might look like this:
Now that we have some code, it's time for testing.
Create unit test projects and test methods
It is often quicker to generate the unit test project and unit test stubs from your code. Or you can choose to create the unit test project and tests manually depending on your requirements. If you want to create unit tests with a 3rd party framework you will need one of these extensions installed: NUnit or xUnit.
Generate unit test project and unit test stubs![]()
Create the unit test project and unit tests manually
A unit test project usually mirrors the structure of a single code project. In the MyBank example, you add two unit test projects named
AccountsTests and BankDbTests to the MyBanks solution. The test project names are arbitrary, but adopting a standard naming convention is a good idea.
To add a unit test project to a solution:
Each unit test project contains classes that mirror the names of the classes in the code project. In our example, the
AccountsTests project would contain the following classes:
Write your tests
The unit test framework that you use and Visual Studio IntelliSense will guide you through writing the code for your unit tests for a code project. To run in Test Explorer, most frameworks require that you add specific attributes to identify unit test methods. The frameworks also provide a way—usually through assert statements or method attributes—to indicate whether the test method has passed or failed. Other attributes identify optional setup methods that are at class initialization and before each test method and teardown methods that are run after each test method and before the class is destroyed.
The AAA (Arrange, Act, Assert) pattern is a common way of writing unit tests for a method under test.
To test the
CheckingAccount.Withdraw method of our example, we can write two tests: one that verifies the standard behavior of the method, and one that verifies that a withdrawal of more than the balance will fail. In the CheckingAccountTests class, we add the following methods:
For more information about the Microsoft unit testing frameworks, see one of the following topics:
Set timeouts for unit tests
If you're using the MSTest framework, you can use the TimeoutAttribute to set a timeout on an individual test method:
To set the timeout to the maximum allowed:
Run tests in Test Explorer
When you build the test project, the tests appear in Test Explorer. If Test Explorer is not visible, choose Test on the Visual Studio menu, choose Windows, and then choose Test Explorer.
As you run, write, and rerun your tests, the Test Explorer can display the results in groups of Failed Tests, Passed Tests, Skipped Tests and Not Run Tests. You can choose different group by options in the toolbar.
You can also filter the tests in any view by matching text in the search box at the global level or by selecting one of the pre-defined filters. You can run any selection of the tests at any time. The results of a test run are immediately apparent in the pass/fail bar at the top of the explorer window. Details of a test method result are displayed when you select the test.
Run and view tests
The Test Explorer toolbar helps you discover, organize, and run the tests that you are interested in.
You can choose Run All to run all your tests, or choose Run to choose a subset of tests to run. Select a test to view the details of that test in the test details pane. Choose Open Test from the right-click menu (Keyboard: F12) to display the source code for the selected test.
If individual tests have no dependencies that prevent them from being run in any order, turn on parallel test execution with the toggle button on the toolbar. This can noticeably reduce the time taken to run all the tests.
If individual tests have no dependencies that prevent them from being run in any order, turn on parallel test execution in the settings menu of the toolbar. This can noticeably reduce the time taken to run all the tests.
Run tests after every build
Note
Running unit tests after each build requires Visual Studio 2017 Enterprise edition or Visual Studio 2019. In Visual Studio 2019, the feature is available in Community and Professional edition, in addition to Enterprise edition.
To run your unit tests after each local build, open the settings icon in the Test Explorer toolbar and select Run Tests After Build.
Filter and group the test list
When you have a large number of tests, you can type in the Test Explorer search box to filter the list by the specified string. You can restrict your filter event more by choosing from the filter list.
For more information, see Run unit tests with Test Explorer.
Q&A
Q: How do I debug unit tests?
A: Use Test Explorer to start a debugging session for your tests. Stepping through your code with the Visual Studio debugger seamlessly takes you back and forth between the unit tests and the project under test. To start debugging:
Learn more details about debugging unit tests.
Q: If I'm using TDD, how do I generate code from my tests?
A: Use Quick Actions to generate classes and methods in your project code. Write a statement in a test method that calls the class or method that you want to generate, then open the lightbulb that appears under the error. If the call is to a constructor of the new class, choose Generate type from the menu and follow the wizard to insert the class in your code project. If the call is to a method, choose Generate method from the IntelliSense menu.
Q: Can I create unit tests that take multiple sets of data as input to run the test?
A: Yes. Data-driven test methods let you test a range of values with a single unit test method. Use a
DataSource attribute for the test method that specifies the data source and table that contains the variable values that you want to test. In the method body, you assign the row values to variables using the TestContext.DataRow[ ColumnName] indexer.
Note
These procedures apply only to test methods that you write by using the Microsoft unit test framework for managed code. If you're using a different framework, consult the framework documentation for equivalent functionality.
For example, assume we add an unnecessary method to the
CheckingAccount class that is named AddIntegerHelper . AddIntegerHelper adds two integers.
To create a data-driven test for the
AddIntegerHelper method, we first create an Access database named AccountsTest.accdb and a table named AddIntegerHelperData . The AddIntegerHelperData table defines columns to specify the first and second operands of the addition and a column to specify the expected result. We fill a number of rows with appropriate values.
The attributed method runs once for each row in the table. Test Explorer reports a test failure for the method if any of the iterations fail. The test results detail pane for the method shows you the pass/fail status method for each row of data.
Learn more about data-driven unit tests.
Q: Can I view how much of my code is tested by my unit tests?
A: Yes. You can determine the amount of your code that is actually being tested by your unit tests by using the Visual Studio code coverage tool in Visual Studio Enterprise. Native and managed languages and all unit test frameworks that can be run by the Unit Test Framework are supported.
You can run code coverage on selected tests or on all tests in a solution. The Code Coverage Results window displays the percentage of the blocks of product code that were exercised by line, function, class, namespace and module.
To run code coverage for test methods in a solution, choose Test > Analyze Code Coverage for All Tests.
Coverage results appear in the Code Coverage Results window.
Learn more about code coverage .
Q: Can I test methods in my code that have external dependencies?
A: Yes. If you have Visual Studio Enterprise, Microsoft Fakes can be used with test methods that you write by using unit test frameworks for managed code.
Microsoft Fakes uses two approaches to create substitute classes for external dependencies:
In both approaches, you use the generated delegates of calls to the dependency method to specify the behavior that you want in the test method.
Learn more about isolating unit test methods with Microsoft Fakes.
Q: Can I use other unit test frameworks to create unit tests?
A: Yes, follow these steps to find and install other frameworks. After you restart Visual Studio, reopen your solution to create your unit tests, and then select your installed frameworks here:
Your unit test stubs will be created using the selected framework.
IntroductionA Unit Test is a part of software development that is done by the development team at the time of development. Basically it is used to test the smallest unit of code, like methods, properties, classes and assemblies also. Where the smallest unit of code is known as a unit.Good news for us is that Microsoft announced a new feature of unit testing with Visual Studio 2015 Preview at the day #vsconnect, in other words Smart Unit Test. When we apply a smart unit test, we can easily identify which unit of tests are not executing depending on our expectation and we can add some necessary code to fix that problem.In other words, we can say that ' Smart Unit Test' is an enhanced feature of Visual Studio 2015 that assists us in finding bugs inside the test units.
Basically it generates a suite of tests for every possible code path in your.NET code. It will automatically evolve the test suit as your code under test evolves. But we will discuss it in a future article. We are now going to do the unit test in Visual Studio 2013 with a Console Application. Before starting the project for Unit Testing, let's see some basic concept of unit testing.Purpose: The main purpose of unit testing is to take the small unit of code from the project, separate it from the code and check whether or not it behaves exactly the same as we expect. So we first do the unit test with each unit of test before integrating them into the project's modules.Use the following procedure to do the Unit Test with a Console Application.Step 1: Open Visual Studio 2013.Step 2: Create a new project in Visual Studio 2013.Seelct 'FILE' - 'New' - 'Project.' .Step 3: Select the project language as C# and select a Console Application and enter the name of the project as Mathematics (Project Name).Step 4: Now write the following method that will identify the type of triangle.
Like the triangle may either be Equilateral, Isosceles or Scalene. Before writing the following methods in your application, first the replace the name of class as Trigonometric in the place of Program (default class name in Console Application) and define the following variables as global variables.
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