Recently I was updating and fixing some existing unit tests after doing a (rather large) overhaul of code.The unit test previously needed to wait for an asynchronous callback to finish before continuing, something like this: Note the optional done parameter provided to beforeEach. This is a void function that signals Jasmine that the callback is … [Read more…]
In Jasmine, you can expect an object toBe another object. However, this will check to see if the two arrays point to the same reference object. In other words, it will check to see if the arrays point to the same memory address. Produces this not-very-helpful error message: Expected [ 42, ‘Forty-Two’ ] to be … [Read more…]
Recently I had a problem where in an Angular unit test where I had an object that was being initialized in ngOnInit from a service. As far as I could tell, everything should be working, but the test would fail because I was trying to set a property on the object before it had finished … [Read more…]
I find that writing unit tests in JavaScript kind of sucks, so this post will (hopefully) serve as a cheat sheet of all the stuff I keep looking up. As such, it will be updated as I learn new stuffs. How To: scope test run to specific tests Remember to set it back before you … [Read more…]
JavaScript is pretty dumb. I know its the most popular language right now (due to the pervasiveness of browsers and other things that can run it), but, I mean, its just… dumb. Luckily TypeScript is pretty awesome. It takes a lot of what makes JavaScript stupid and fixes it. It makes it a lot more … [Read more…]
I hate magic things. In programming, I mean. I try to avoid magic strings and magic numbers as much as possible because I can barely remember the thing I typed five seconds ago, let alone something that you have to maybe type five hours from now. So, I tend to use a lot of enums … [Read more…]
I was trying to be good and keep up with my Karma unit tests in my Angular 5 Typescript project, but I was running in to a really weird error that left a lot to be desired: The logs in the console window are not helpful either… Chrome 63.0.3239 (Windows 10 0.0.0) ERROR Uncaught NetworkError: … [Read more…]
Regular expressions are powerful, but I find that they’re also incredibly annoying to use. Recently I was trying to create a parser that would try a few different regular expressions and output an object with the proper fields defined. The input was a string separated by periods, so it was fairly easy to create the … [Read more…]
When you write code against an Observable, you subscribe to the result. In the subscribe method you provide the callbacks to perform when the Observable is called back. That means you can execute different code for success and failure. In the last post I wrote about how to mock up and test Observable<T> in Jasmine … [Read more…]
Say that you created a service that essentially wraps Angular’s HttpClient calls: And say that you called that in a component: And now you want to test the Get function to make sure that myValue is set to the value returned by the service. If you try to create a spy on the function in … [Read more…]