More importantly, if we wanted to test our waiters could actually apologize to customers in the cases where a meal is delayed or cannot be made we would literally be waiting until our cooks were too slow or we ran out of ingredients before our tests for those cases could be confirmed.

This directory will have a view to show all of our users along with another view to serve as a profile page for individual users. These are the main concepts: Test a component with services. Let’s go through the more important ones;To run the test you only need to run the command “ng test”. Whenever we create files using the CLI, as well as creating the main code file it also creates a simple Jasmine spec file named the same as the main code file but ending in .spec.ts.

As we said, this is a good practice even if we only have one spec. ; Basics of testing components—discover the basics of testing Angular components. I find this concept is easiest to illustrate with a real world example.Imagine you own a restaurant and it’s the night before opening day. Angular was designed with testability in mind and it provides multiple options to support Unit Testing. but if you are not convinced yet let’s mention a couple more.You can say that all their benefits come at a great cost: TIME, but this is completely false. As a result of this process you'll find you have better feature documentation for yourself and other developers as well as a design aid for your APIs.Karma is a direct product of the AngularJS team from struggling to test their own framework features with existing tools. We will use a very basic directive, myProfile, that renders a user profile so you can grasp the basic idea. Code coverage—find out how much of your app your tests are covering and how to specify required amounts. Just like our kitchen example, if we were testing our application’s ability to handle an API call that failed we would literally have to wait for our API to fail to verify it could handle that case—a scenario that hopefully won’t be happening that often!To get this test to pass, we need to implement the service method in First, we'll start by adding our imports and a collection of employees to the service.Then, just below our constructor, we can implement Now that our service method is ready to use, we can work towards populating our home page with these users.First we import our service and inject it into our component's constructor.

Jasmine is a behavior-driven development framework for testing JavaScript code that plays very well with Karma. The thing is that you probably don’t want to use the actual services but a mocked version instead, so let’s see how to do that…First, let’s take a look at the implementation of the component;This is a simple component that gets the list of users from a service.The actual service implementation is not important it could be getting the users from anywhere, but let’s see how we create the tests for the component mocking the service implementation.This test is similar to the examples we saw before with one main difference, in the provider’s declaration of the test module we are telling the module that when the service “UserService” is injected it should use the “UserServiceMock” instead. Other than being a cute alien companion Adder can really only do one thing, add two numbers together.To verify Adder's ability to add two numbers we could generate a set of test cases to see if Adder provides us the correct answer.Within Jasmine, this would begin with what's referred to as a From here we could provide Adder with a set of test cases such as two positive numbers (2, 4), a positive number and a zero (3, 0), a positive number and a negative number (5, -2), and so on.There are many other matchers available to us other than toEqual. Using Jasmine framework to test Angular Router. We mock the response we may expect to receive and verify that our application can handle that response accordingly. Angular also provides utilities like TestBed and async to make testing asynchronous code, components, directives or services … The time spent resolving bugs is going to be drastically smaller than if you are not using unit testing.Let’s have some fun… we are going to create a small but quite complete example of an application using Angular, Jasmine and Karma.These are some of the things that we are going to talk about:As the angular team recommends we are going to use When you create the project all the dependencies get installed among them everything you are going to need to create the tests.In the image above you can see all the dependencies installed for testing purposes.

Follow. This directory will have a view to show all of our users along with another view to serve as a profile page for individual users. This component only has a property “text” with the value “Angular Unit Testing” that is rendered in the HTML inside an “h1” tag, it also contains the routing root element and some routing links. For this reason, we would “mock” the backend (kitchen) and give the waiters whatever scenario it is that we want to test.Similarly in code, we don’t actually hit the API when we’re testing various scenarios. On this occasion we are checking each individual language and the total count.Directives usually encapsulate complex functionality and interactions so writing comprehensive unit tests become a mandatory task.