Angular CLI has test coverage reporting somewhat built in.
First install the dependencies.
$ npm install karma karma-jasmine karma-chrome-launcher karma-jasmine-html-reporter karma-coverage-istanbul-reporter
Then run ng test
.
$ ng test --code-coverage
Then run the server that shows you your report.
$ http-server -c-1 -o -p 9875 ./coverage
You should see something like this.