MW-CS should enforce the one class per file requirement (there's an upstream sniff for this). This will be necessary in preparation for the PSR-4 namespaceization project.
Related Gerrit Patches:
|mediawiki/tools/codesniffer : master||Use local OneClassPerFile sniff for only one class/interface/trait|
|mediawiki/tools/codesniffer : master||Require only one class/interface/trait per file|
|Open||None||T166010 The Great Namespaceization and Reorg|
|Resolved||Legoktm||T173798 Enforce one class per file in preparation for PSR-4|
Unfortunately this doesn't exactly do what we need. This enforces separately one class per file, one interface per file, etc. But it doesn't prevent a file from having one class and a interface in the same file.