The criterion for recognising the hypocrites is their negative attitude towards Ameerul Mo'mineen Ali (AS). Virtuous companions have heard from the Prophet Muhammad (SAWA) that no one likes Ali but a believer, and no one dislikes Ali but a Munafiq (hypocrite). This authentic Hadeeth is narrated in Saheeh Muslim (number 113) and Musnad Ahmad ibn Hanbal and Tirmithi and Ibn Maajah and many books of Hadeeth.
Wassalam.