Does divorce occur by saying, "Upon me be divorce if I do not betray her," with the intention of pleasing the wife, and is it considered a contingent divorce or an oath?

Treachery is forbidden. The aforementioned oath is an oath of divorce predicated on not betraying the wife. If no betrayal occurs, then nothing happens. However, if betrayal, in the intended sense, does occur, then the divorce takes effect according to the majority of scholars (including the four Madhhabs), and this is the preponderant opinion. As for Sheikh al-Islam Ibn Taymiyyah and those who agreed with him, they hold that an expiation for an oath (kaffarat yameen) is obligatory if the divorce was not intended. In the event of divorce, the wife can be taken back (revocable divorce) before the expiry of her 'iddah, provided this is not the third divorce.