Shouldn't there be the word "par" in the test phrase?

Question

The correct answer for the question: Il ________ repassé chez toi hier soir.

He passed by yours again yesterday evening.
Is being given as "est". However there is no preposition before "chez toi". Is the "par" to be assumed ?

Accepted Answer

Both is possible: Repasser chez toi means "to go back by your place". In my understanding, if you add par to that, it means that you stopped by on the way to somewhere else.

Answer

Chris, thanks for the reply.  In light of your response, I searched a bit more and found an even more thorough response in that "chez" is itself a preposition, thus as you said, to include par is either unnecessary or changes the meaning of the sentence.

Answer

You can, howerver, say Je passe devant chez toi. -- I am passing in front of your house.