Angular 2 has landed! Rejoice! After 18 beta releases and 8 release candidates, the final version saw the light of day in September and you can now consider it stable enough to use it. It’s a totally different framework when you try to compare it with 1.x but the principles are the same. You get the proper tools to build your web application from the UI to the data retrieval and everything in between. The plan is to have multiple quick tips appear here as I play with it. To start this process I will try to explain one of the concepts that took me a while to grasp once I started migrating one of my applications to Angular 2, the module system!
Dependency injection is your friend when you want your code to be testable and if you work with Angular you know that this is a fundamental concept. Angular 2 will be developed with TypeScript but if you want type safety you can use TypeScript with Angular 1.x today as well. When it comes to DI with Angular and TypeScript, you can do some pretty nice stuff.
Time for the second part of the small unit testing guide that started with this post. In the first part, we’ve introduced a very basic function that calculated the age of a person based on a parameter that represented the year of birth. Before making the calculation, the parameter was checked to make sure it’s a number and if it wasn’t the function threw an error. Both use cases are small and perfect to have some test written for them so let’s begin.