Eslint angular and jasmine: is not defined no-undef
You can add /* eslint-env jasmine */ to the top of your .spec.ts files. This is basically the same solution as the one proposed by Geert, but with a per-file solution. The subtle difference is that it will still be an error to use some of the globally defined test methods like describe() and it() in your non-test files.
(There is probably a clever way to set up ESLint, so that you don't have add this line to all the .spec.ts files.)