[Scripting Question] Form-based evolution

[Segaz3]

I'm creating the evolution methods for Alolan and Galarian pokémons. Right now, I am trying to make Galarian Mr. Mime evolve and I have made this script:

GameData::Evolution.register({
  :id            => :LevelFirstForm,
  :parameter     => Integer,
  :level_up_proc => proc { |pkmn, parameter|
    if pkmn.form = 2
      next pkmn.level = parameter
    end
  }
})

However, Kantonian Mr. Mime evolves too for some reason (yes, I have added this new evolution method to Mr. Mime). At this point, I tried replacing pkmn.form = 2 with pkmn.form != 2 and the same happens. How is that even possible? How can a pokémon be in its second form and at the same time don't?

 

[Segaz3]

I found the problem: there have to be two =s instead of one, that was why