What is the test for self serving affidavits?

It has been said that the parties must put forward "their best foot". Self serving affidavits do not create triable issues in the absence of detailed facts and supporting evidence. "The motion judge must not usurp or assume the role of a trial judge by adjudicating on any genuine factual issues and should not assess credibility, weigh the evidence, or find the facts, all of which are functions reserved to the trial judge." At the end of the day, the motions judge must take a hard look "at the merits of a claim or defence. Oakley v. Montreal Trust Co. (2001) O.J. No.3827 (S.C.J.) Power J. at paragraph 13 (B)(a).