Error while testing small units of my app

I am a beginner in Angular 5 Testing. I have created a new ap using ng in Angular5 and trying to test it with Karma and Jasmine. The app functions very well in my ocalhost, but when I do testing a message appears like in the image: enter image description here

It is suposed that the tests are passed since the app is very simple and I have done anything correctly. But this message is confusing me. Is there any suggestion?

I have consulted with previous questions about ths problem but none seem to have an answer that could help.

Is there something that is wrng with my app?

Thanks,