Code coverage reports

A good way to understand the amount and the trends of unit test coverage for your Angular project is through a code coverage report.

In order to generate the report for your app, execute the following command from your project folder:

$ npx ng test --browsers ChromiumNoSandbox --watch=false --code-coverage

The resulting report will be created as an HTML file under a folder named coverage; execute the following command to view it in your browser:

$ npx http-server -c-1 -o -p 9875 ./coverage

Install http-server as a development dependency in your project.

Here's the folder-level sample coverage report generated by istanbul/nyc for LemonMart:

Figure 9.20: Istanbul code coverage report for LemonMart

You can drill down on a particular folder, such as src/app/auth, and get a file-level report, as shown here:

Figure 9.21: Istanbul code coverage report for src/app/auth

You can drill down further to...