Writing system tests
System tests verify that Stylelint works as expected. They are another line of defense against regressions, after the unit tests and integration tests.
Each of these system tests asserts that we end up with some expected output, given a configuration and a stylesheet.
These tests should not be comprehensive and systematic (the unit tests should). They should reproduce real use-cases and verify that those use-cases work as expected.
Jest snapshots
The tests use Jest snapshots, so we can easily:
- assert against potentially large objects and strings
- update expectations as needed.
The pattern
To add a system test, you should:
- add a test-case folder to
system-tests/incrementing the number from existing test cases - add a configuration file and a stylesheet
- add a
fs.test.jsandno-fs.test.jsfollowing the format established by existing tests, and using thesystemTestUtils - take a snapshot of
output