Timing for work permit and residence permit

Hello,

I should receive soon the notification for foreigner's work permit to be able to apply for a Z visa in France. Once I enter China (Shanghai) I need to get the work permit and residence permit. Could you please let me know how long the process is gonna take. I have read 5 working days for the work permit (other websites say 15 working days) and 7 working days for the residence permit. Do you have any information on how long the process really takes in Shanghai? Because I am supposed to take a flight back at the end of June and I want to be sure I will have my passport back.

Many thanks and kind regards,
Erika