Picked up by unit tests? How about some kind of system which can tell you if the method exists or not, and even possibly correct your typos, before you run the code!
Completely fair, but that's often not built into dynamic languages. My main criticism is with their nonsensical approach to dealing with the limitations of JavaScript.
As far a I know, ESlint can't detect missing methods, and they weren't even using a linter. TypeScript can, but they weren't using that.
