03_Creating_Tests_for_a_Project.md

Create Test Files for a Project

Console (.NET)

Note… instructions are for Microsoft Visual Studio Enterprise 2022 Version 17.4.4. It may be slightly different for different versions of Visual Studio.

Tutorial

Useful tutorial on testing (but we are using a different test project, XUnit). A little outdated, but very informative.

A good read on testing basics: Unit testing fundamentals

Create Test Project

NOTE: These instructions may change as we (your teachers) figure out which is the best testing framework for automated testing on Git.

• Open Visual Studio

• Choose File->Open->Project/Solution, and open your solution

• Choose File->New->Project

• You must find the xUnit Test Project (.NET Core). Make sure to choose the C# version.

  

• Click Next

• BEFORE CLICKING CREATE…Make sure that the “option” for the “solution” is add to solution, not “create new solution”.

  

Preparations Before Testing

• Link your project to the test suite

  • Right click References in your Test Project (in Solution Explorer)

  • Choose Add->Reference

    

  • Find the project you want to test, and select it,

  • 

  • click OK

  • Verify!

    

• Give your test code access to the code you want to test

  • Open UnitTest1.cs

    NOTE: if using Xunit is giving an error, just be patient, Visual Studio will download the necessary files automatically.

  • You must use the namespace of the code you want to test.

  • Example: using Budget;

Writing a Test

In your test file, you must include the [FACT] keyword to indicate which classes/methods are part of testing, as opposed to helper functions.

[Fact]
public void SomethingMethod_Test()
{
  // this is a test
}

Assert

Tests are validated through a series of Assert statements, which will cause specific exceptions to be created. The testing framework will capture these exceptions, creating a list of passed and failed tests.

Example Test

[Fact]
public void CategoriesMethod_Delete()
{
    // Arrange
    Categories categories = new Categories(testInputFile);
    int IdToDelete = 3;

    // Act
    categories.Delete(IdToDelete);
    List<Category> categoriesList = categories.List();

    // Assert
    Assert.Equal(numberOfCategoriesInFile - 1, sizeOfList);
    Assert.False(categoriesList.Exists(e => e.Id == IdToDelete), 
                 "correct Category item deleted");
}

Adding Test Files

• If any test files already exist, add them to your project the same way you would add files to any project

Student Activity

• a Console .NET project (call it 'Budget' to keep it simple).
• Add all the necessary files (get them from LEA)
• Create a new Xunit project (within the same solution)
  • Don't forget to add the reference to the budget project
• Add all the test files to the test project.

NOTE: For HomeBudget tests, there are additional test files which must also be included into the project. In other words, include all files.

• Delete unitTest1.cs

Viewing Your Test Files

• Select View -> Test Explorer

  • You will now have a panel, where you can choose to run your tests, run specific tests, etc.

• You may need to rebuild your solution to see the tests.

Running Tests

• From Test Explorer, you can click on the green arrow to choose which tests to run.

Debug a Failing Test

• The details of a failing test (if selected) will be shown in the Test Detail Summary window. This information includes a stack trace, which will indicate which assert failed.

  • This will allow you to go directly to the failing Assert.

• Debugging

  • You can set breakpoints in tests, and in your project code, as per usual
  • To debug, select test(s) that you wish to debug, right click, and select debug

Student Activity

In our course, we will eventually be building a WPF (gui) app using the budget code files, however…

• Out of 60-some tests, there are some failing tests!

  • you will expected to debug, and fix them before proceeding to make any modifications

• In class exercise... debug the failing test: TestCategories.Categories_TypeAllDayEventReadCorrectlyFromFile

• what other tests are still failing?