Angular: Does Karma have to compile all my code every time I run `ng test`?

Question

Every time I run ng test in my (fairly standard) Angular 8 project with Jasmine and Karma, I find that Karma builds all of my code before tests start running in the launched browser.

Is there a way for me to tell Karma to only build code that has changed from the last time I ran ng test? Or some other mechanism for shortening the time between changing my code and seeing the results from my tests with Karma?

user_3211922 · Answer

If you are using Visual Studio Code you could install the "Angular/Karma Test Explorer": https://marketplace.visualstudio.com/items?itemName=raagh.angular-karma-test-explorer

It easily let's you run a single test or a single test file at a time. It is still not super smooth, but it is certainly better and faster than relying on "ng test" and the browser window.

Angular: Does Karma have to compile all my code every time I run `ng test`?

1 Answers