The Angular CLI comes with Karma and Jasmine so that it can run unit test cases out of the box. Jasmine has been out there longer, but apart from Jasmine, there are other test runners in the JavaScript community. Some of the most popular ones are Mocha and Jest. Jest is one of the latest test runners and comes from Facebook. It is not only fast and easy to configure but also delightful to test with. It also allows you to perform a new kind of testing known as snapshot testing.
Let's configure jest using the ng add command:
> ng add @davinkevin/jest
This is one of the many community-provided schematics that adds Jest support, though others can add support too, such as @briebug/jest-schematic, @itrulia/jest-schematic, @ockilson/ng-jest, and so on.
Now, let's run the test command using the new script that we added to...