Angular Testing with Jasmine/

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Write a Unit Test

Write a Unit Test

Learn how to test a basic Angular component.

We'll cover the following...

Testing an Angular component

Let’s take a look at the files created when we generate a new component using the Angular CLI. For example, we could use the generate command to create an ArticlesIndex component:

ng generate component ArticlesIndex

When Angular generates the component, it creates four files:

articles-index.component.html
articles-index.component.spec.ts
articles-index.component.ts
articles-index.component.css

Angular generates a basic test for us in articles-index.component.spec.ts. At the end of the file, there is an example test that Angular has written for us. The toBeTruthy method tests that our result is true when interpreted as a boolean. All values are considered to be truthy except for the following falsy values: false, 0, -0, "", null, NAN, and undefined. So, in this case, our component variable will be truthy if it was created successfully.

it('should create', () => {
  expect(component).toBeTruthy();
});

Try running your first Angular component test in the code widget below:

Angular component test
Remember that our goal in unit testing is to isolate the component or part of the system that we want to test. In this case, Angular ...