Surely it is an international norm that you file your tax return in your country of residence. What tax you then pay and to whom then becomes a potential argumentative subject. You can find out some more about it all here.
Impots.gouv.fr
The French are quite amusing from time to time. I think you will find that, if you have ever joined the French health service, you are a resident of France as far as the financial authorities are concerned because you have no right to join the French healthcare system unless you are a resident of France.