If your client has left Canada never to return except as a visitor, then you file a part-year return showing the date of departure.  However, there are issues when a Canadian resident becomes non-res that you need to address.  Most notably, the emigrant may have to pay departure tax  because of a deemed disposition on certain types of property, and a T1161 may have to be filled out as well as a T1243 or T1244.  If  your client has an investment portfolio, this comes into play as CRA does not look kindly on taxpayers leaving town with a lot of unrealized capital gains and then cashing in elsewhere.

Hope this helps.

Jo