There are no strict rules regarding organizing tests into modules vs classes. It is a matter of personal preference. Initially I tried organizing tests into classes, after some time I realized I had no use for another level of organization. Nowadays I just collect test functions into modules (files).
I could see a valid use case when some tests could be logically organized into same file, but still have additional level of organization into classes (for instance to make use of class scoped fixture). But this can also be done just splitting into multiple modules.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…