I don't want to rail on the author here - lord knows I've written some JavaScript that I regret now - However, putting things on an event bus does not make modules independent, testable, or re-usable. You get those things from careful planning.

You are still going to introduce conceptual dependencies between modules. I'd personally rather have explicit control over those dependencies and their interfaces rather than passing it through a bus.

But anyway, y'all, if class A depends on class B, formalize the interface between the two (throw an error when expectations aren't met) and then inject the instance!