Topic on Manual talk:Pre-commit checklist/Flow

Moved from How to become a MediaWiki hacker:

Testing

When adding features, it's vital to verify you didn't break existing functionality. The usual tool for this is automated testing frameworks. MediaWiki's test suite is still relatively sparse. We have three kinds of tests:

• Parser tests (see tests/parserTests.php), which only test the parser. Try running php tests/parserTests.php --quick --quiet to see how those work. Everything should pass, in theory. You can add new tests or fix existing ones by editing tests/parserTests.txt.
• PHPUnit-based unit tests in the tests/phpunit directory. They are typically run through the phpunit.php script invoked from the aforementioned directory. These tests also include ordinary parser tests, though parserTests.php probably works faster. See Manual:PHP unit testing for PHPUnit setup instructions and further details.
• Selenium tests are in directory tests/selenium.

Anyway, if you can't write an automatic test, do manual testing. If you cause breakage too often, people will get annoyed at you, especially if it isn't caught until it goes live on Wikipedia. Revocation of commit access has been threatened in the past occasionally. At the very least, expect serious indignation if you check in syntax errors – try at least loading your wiki, or

php maintenance/checkSyntax.php --modified.

done.

The checkSyntax.php --modified documentation says "check only files modified in the current working copy (requires that the script is run from a Subversion checkout and that the SVN command-line client is present. Use this option to quickly check your changes before committing them to the repository." So, what about git?

Filed https://bugzilla.wikimedia.org/show_bug.cgi?id=42392