How do I debug a "[object ErrorEvent] thrown" error in my Karma/Jasmine tests?
FYI: you can find the exact error thrown just by open DevTools Console once your tests are running.
As a quickfix you can try to run your tests without sourcemaps:
CLI v6.0.8 and above--source-map=false
CLI v6.0.x early versions--sourceMap=false
CLI v1.x--sourcemaps=false
Shortcut
ng test -sm=false
might also work
There is an open issue on that https://github.com/angular/angular-cli/issues/7296
UPDATE:
I had that issue as well, so I just migrated to the latest cli and make sure that all packages are updated in package.json
also I fully reinstalled the node_modules
so now the issue has gone.
If sourcemap=false doesn't help, try to 1) open your browser running the tests 2) click debug button 3) open the console
The error will be there