frontend-testing.md

Frontend Testing

Unit tests are written in Jest, with snapshot tests for ensuring components don't inadvertently change.

To run the React test suite:

make test-react

To run a subset of tests, use the FILES argument, using a space as a delimiter between file paths:

make test-react FILES="src/components/Navigation/Navigation.test.jsx src/components/Navigation/SectionLink.test.jsx"

If changes are made that require updating a snapshot(s), pass the appropriate flag using the FLAGS argument:

make test-react FLAGS="--updateSnapshot"

Information about integration tests.

Test Coverage

In order to maintain high quality code and reduce defects, all merged code is expected to have accompanying tests. We track code coverage by leveraging Istanbul, which is included with Jest.

By default, coverage reports are hidden because it causes the tests to run slower and the report outputs are verbose. It is up to each individual developer to setup their personal development environment if they want to see the coverage report.

In package.json, under scripts, there is a command called test. Coverage reports can be turned on by adding the --coverage flag.

In addition to that, an HTML version of the coverage report located at coverage/lcov-report/index.html.