How to run angular 4 karma tests on circleci

Here is what I had to add to my circle.yml

machine:
node:
version: 6.10.1

test:
override:
- npm run-script test:once

1) Setting node version is important on CircleCI otherwise you’ll get a bunch of peer dependencies errors.
2) Karma is set up to run tests continuously, which is not good on CircleCI.