Testing the auth service and component(s)
Before we finish implementing the auth section, we need to add automatic tests to our implementation to detect any hidden errors that we might miss when manually testing.
When we generate our project with the Angular command-line interface (Angular CLI), we also have testing configured with a number of initial tests that are added to ensure that artifacts, such as components and services, are properly instantiated.
If you're new to Angular testing, start by reading https://angular.io/guide/testing and https://techiediaries.com/angular/jasmine-unit-testing, then learn how to write your first test suite at https://jasmine.github.io/tutorials/your_first_suite.
Also, before testing Apollo Client APIs, make sure to read the official testing documentation at https://apollo-angular.com/docs/development-and-testing/testing/.
Jasmine includes a set of APIs that make it simple to write unit tests. We basically have three options, as...