End-to-End (e2e) Testing-
The End to End Testing is used to testing the entire application looks like -
1. All User Interactions
2. All Service Calls
3. Authentication/Authorization of app
4. Everything of App
This is the actual testing of your append it is fast action.
Unit testing and Integrations testing will do as fake calls but e2e testing is done with your actual Services and APIs calls.
Recommended Unit Testing Tools –
1. Karma
2. Jasmine and
3. QUnit
For more detail kindly refer my blog-https://www.code-sample.com/2018/05/angular-7-6-5-testing-questions-and.html