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tests that exercise your ASP.NET Core application. Unit tests are small
tests that make sure a single method or chunk of logic works properly.
Integration tests (sometimes called functional tests) are larger tests that
simulate real-world scenarios and test multiple layers or parts of your
application.
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Unit testing
Unit testing
Unit tests are small, short tests that check the behavior of a single
method or class. When the code you're testing relies on other methods
or classes, unit tests rely on mocking those other classes so that the test
only focuses on one thing at a time.
For example, the TodoController class has two dependencies: an
ITodoItemService and the UserManager . The TodoItemService , in turn,
depends on the ApplicationDbContext . (The idea that you can draw a
line from TodoController > TodoItemService > ApplicationDbContext is
called a dependency graph).
When the application runs normally, the ASP.NET Core service container
and dependency injection system injects each of those objects into the
dependency graph when the TodoController or the TodoItemService is
created.
When you write a unit test, on the other hand, you have to handle the
dependency graph yourself. It's typical to provide test-only or "mocked"
versions of those dependencies. This means you can isolate just the logic
in the class or method you are testing. (This is important! If you're testing
a service, you don't want to also be accidentally writing to your
database.)
Create a test project
It's a best practice to create a separate project for your tests, so they are
kept separate from your application code. The new test project should
live in a directory that's next to (not inside) your main project's directory.
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Unit testing
If you're currently in your project directory, cd up one level. (This root
directory will also be called AspNetCoreTodo ). Then use this command to
scaffold a new test project:
dotnet new xunit -o AspNetCoreTodo.UnitTests
xUnit.NET is a popular test framework for .NET code that can be used to
write both unit and integration tests. Like everything else, it's a set of
NuGet packages that can be installed in any project. The dotnet new
xunit template already includes everything you need.
Your directory structure should now look like this:
AspNetCoreTodo/
AspNetCoreTodo/
AspNetCoreTodo.csproj
Controllers/
(etc...)
AspNetCoreTodo.UnitTests/
AspNetCoreTodo.UnitTests.csproj
Since the test project will use the classes defined in your main project,