I have an app and it runs fine if I do rackup or puma but it doesn't run when I do ruby app.rb I tried puttingrequire 'sinatra'run Sinatra::Application on the bottom but it says run is not defined.
If you're writing an app in classic mode, you don't need to run it at the bottom of the file; it runs automatically if invoked directly (i.e. ruby app.rb). If you're writing an app in modular mode, you can put a run! at the bottom of the class to run it automatically if it's invoked directly:
I have it in the classic mode but for some reason it doesn't run when I invoke it that way.