Unit tests for file names

There's integration testing for this but the logic should probably be split out and tested as unit tests too

Start by locating the existing integration tests for file names and the logic they exercise. Trace how that logic is organized and identify the appropriate unit-test entry point. Done means the file-name behavior is covered by unit tests while the existing integration coverage remains valid.

Rédigé par le modèle d'indexation à partir du texte de l'issue.