v2.0

Changelog

• Added new getNewPhpcsMessagesFromFiles() top-level function which provides a more clean abstraction over the library's internals.
• Added --report option to allow json and phpcs "full" reporting (default is now full, to match phpcs).
• json report now prints output even if there are no messages (full report does not).
• Output now includes the filename, if available from the diff.