Intro to Software Testing

Software Testing :

>> Unit tests :  they provide more depth than E2E tests. It's easier to verify specific conditions the code will face. It's also easy to mock out all dependencies as necessary and test just the component the unit tests is interested in.

Unit tests don't concern themselves with how the UI works, or that the right data is bound correctly, but rather than the business logic of the app is correct.

>> E2E tests : less granularity, focusing on making sure the UI looks as expected from an end user perspective. You are right that it's messy to test against a live database (although some people enjoy the safety provided by a full end-to-end integration test), and so you should use $httpBackend to mock out the server.

>> Mocha : is a feature-rich JavaScript test framework running on Node.js and in the browser, making asynchronous testing simple and fun.

>> Jest is an open JavaScript testing library from Facebook. Its slogan is "Delightful JavaScript Testing".
While Jest can be used to test any JavaScript library, it shines when it comes to React and React Native. This is no surprise as both React and Jest come from Facebook, which is a major user of both.

>> WebDriver : is a web automation framework that allows you to execute your tests against different browsers, not just Firefox (unlike Selenium IDE). WebDriver also enables you to use a programming language in creating your test scripts (not possible in Selenium IDE).