Purpose

The FreshQuality project provides testing tools for projects in .Net Standard 2.0 or later. Most notably the TestBase provides a mechanism for testing classes that are instantiated using IOC, a common scenario being Controllers from a MVC project.

License

• BSD-3 Clause

Minimum Requirements

• .Net Standard 2.0

Underlying Implementation

The TestBase class hides the implementation that facillitates easy IOC testing, making it simple to get started. Typically the most difficult part of getting setup is having all necessary Nuget packages and references installed in the test project.

Supporting the TestBase is a mechanism that scans all linked projects for classes that are subclass to the generic type passed into TestBase. It then determines what constructors are available, and which types are used in those constructors. It provides this information in a neededInterfaces variable into the ServiceInitializer method. The information can be printed out to determine which types must be configured for IOC, or creating a test with a Get<T> call can be made, and an error message for missing types needed for T to be instantiated will be provided.

What's Included

To demonstrate the abilities of the FreshQuality project, an example project that implements the code in the tutorial article: https://docs.microsoft.com/en-us/aspnet/core/tutorials/first-web-api?view=aspnetcore-2.1&tabs=visual-studio is provided. This ExampleProject gives a simple Todo list web api using an in-memory datastore.

Also attached to this solution is the ExampleTests has a set of tests which provide automated tests against the TodoController of ExampleProject. The ControllerTests class inherits from the TestBase class, and demonstrates how easy it is to instantiate a controller that has multiple parameters that use dependency injection.

Getting Started

After an MS Test project is created:

1. A reference to the project to be tested should be added.

2. Make the test class inherit from TestBase. TestBase takes 2 generic parameters: - The base class to scan project references for. A common scenario would be ControllerBase to get all MVC controllers. - The typeof the test class. In the ExampleTests, the class ControllerTests would pass in ControllerTests.
   So in the ExampleTests scenario, the class declaration for ControllerTests looks like:

[TestClass]
public class ControllerTests : TestBase<ControllerBase, ControllerTests>

3. Add an override method for ServiceInitializer that registers any services required for the types that will be tested. A good starting place would the services that are added in the Startup.cs of a MVC project. In the ExampleTests, the ServiceInitializer was implemented as follows:

protected override void ServiceInitializer(ServiceCollection services, HashSet<Type> neededInterfaces)
{
  //Note this DB context matches the one in Startup, it doesn't have to so long as 
  //it is a valid context compatible with the code to be tested.
  services.AddDbContext<TodoContext>(opt => opt.UseInMemoryDatabase("TodoList"));
}

4. Create tests as needed, and use the Get<S> method to get instances that TestBase has retrieved. In the ControllerTests example, the type T is ControllerBase, so S can be any type that inherits from ControllerBase. In the ControllerTests.cs a simple tests that gets the controller is included below:

[TestMethod]
public async Task GetTodoItemsResultsList()
{
  var ctrllr = Get<TodoController>();
  
  var result = await ctrllr.GetTodoItems();
  var todoEnumerable = result.Value;
  
  Assert.IsNotNull(todoEnumerable);
  Assert.IsTrue(todoEnumerable.Any());
}

Side by Side Comparison