It’s one thing to get code working in a browser, but it’s another to have confidence in that code to ship it to your users. To get that confidence, you need automated tests. We’ve completely avoided writing tests up to this point because it would complicate the tasks of learning about Angular, Bootstrap, and Postgres. But now that you’ve got a bit of confidence with these new technologies, we’re at a point where we can turn our attention to tests.
In the next chapter, you’ll build on the testing tools that Rails provides and learn how to test database constraints, write unit tests for our Angular code, and write acceptance tests that execute our Angular app in a real browser.
https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/click
https://angular.io/docs/ts/latest/guide/template-syntax.html#binding-syntax
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/template
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/let
https://angular.io/docs/ts/latest/api/common/index/NgFor-directive.html
http://yehudakatz.com/2011/08/11/understanding-javascript-function-invocation-and-this
https://angular.io/docs/ts/latest/api/http/index/Response-class.html