We will be using two primary tools for writing our test cases: Jasmine and Karma. Because we created our application using the Angular CLI, the CLI already adds these dependencies to our solution. The Angular CLI also creates sample test for our application including services and components, which include the initial setup work required to start writing the test. This is very useful for us because we avoid doing the setup work, and can therefore be more productive on what matters most: writing the test for our application.
Though we already have these (Jasmine and Karma) installed in our application, it would be good to look at these tools in isolation and understand them, so that if you would want to develop an application without the Angular CLI, you can use these tools.