Effective July 1 any employer in China can have you detained indefinitely. It used to be that if there was a contract dispute you could just get on a plane and go home.
This is no longer the case.
Pay attention to the breach clause in your contract. If you can't afford to pay it then you can be detained indefinitely and prevented from working while you are detained.
This is no joke.
There are more disreputable employers in China than reputable. This is aimed at controlling foreigners. Also, if you are working on an L visa or an F visa and get caught there are now severe financial penalties.
You guessed it, you will be fined and if you can't pay you will be detained according to the new laws. It is no longer worth it. Your own employer can report you and the only one who suffers is you. See for yourself: