Delete never used cli.rb

[neves]

cli.rb is loaded by pry at startup, looking for cli options to add to pry command options.
This file is slowing pry startup by 50%, but it's never used.
It's ok to not exist, since pry checks it:
https://github.com/pry/pry/blob/master/lib/pry/plugins.rb#L38

The same was proposed to pry-byebug:
deivid-rodriguez/pry-byebug#76

[kyrylo]

I don't remember why it was added, but I guess there's a good reason for it. How did you figure out that it slows the startup time by 50%?

[ConradIrwin]

I think it was to ensure that interception loaded ahead of time. In todays modern times we can probably rely on bundler rather than pry to do this for us.

[neves]

@kyrylo I just copy/paste from byebug. Rescue add about 0.1s to load time on my machine.
But if every plugins adds 0.1s, you got the idea.

[kyrylo]

So without requiring cli.rb it adds only 0.05s, doesn't it?

[neves]

@kyrylo On my machine, pry takes 0.8s to load without plugins. With only rescue, it takes 0.9s.
So 0.1s.
With others plugins, its taking 4s.

[neves]

Just to make it clear, cli.rb is required by pry even if you'll not use it.
For example, if you execute pry -h it will require cli.rb from all pry extensions installed on the system.
That's why the simple existence of this file, slow down pry shell commands.
I have 12 pry-* gems on my system, but only byebug, rescue and theme has cli.rb and none are used.

[ConradIrwin]

@neves The fact that it does a require "pry-rescue" is significant. It's being used (or arguably "abused") to ensure that pry-rescue loads early. It might be that we don't need to do this anymore, as this heralds back to the pre-bundler days (the whole pry plugins system doesn't work well with bundler) but someone would have to test that assumption.

[neves]

@ConradIrwin, actually pry doesn't require if not exists:
https://github.com/pry/pry/blob/master/lib/pry/plugins.rb#L38
Since day one:
pry/pry@9142aa1#diff-7a2e80a6a01c9b6a8fe7bfd120264932R38