What is the test for invalidating a municipal bylaw?

There have been numerous judicial decisions involving an examination of bylaws alleged to be invalid by reason of an uncertainty of the terms thereof, and it appears, quite logically, that the final decision must be based in each instance upon an examination of the intention of council in passing the bylaw: Rogers, The Law of Canadian Municipal Corporations (2nd Ed.), Volume I, page 469 et seq,; and the wording of the impugned bylaw or section thereof: Sampson v. Corporation of the City of Kingston (1981), 33 O.R.(2d) 105, at 119.