Peru should check for the presence of external tools before invoking them about peru HOT 2 OPEN

That hidden abstraction layer is wonderful and one of the things I really like about the tool.

I think this check could be achieved through the use of which , which the shutil built-in has in shutil.which():

import shutil

def is_utility_available(cmd):
  return shutil.which(cmd) is not None

def require_git():
  if not is_utility_available("git"):
    raise MissingUtilityException("git is unavailable. Please install git and re-run your command.")

Drop require_git() early into any path that will need git and the user who forgot git will love the helpful error message instead of a FileNotFoundError or whatever is thrown with a long traceback.

from peru.

The main reason we haven't done something like this already is that peru tries pretty hard to keep itself to a single external invocation of the git binary in the happy path. So like if you run peru sync it does a tun a work and runs a bunch of commands. But if you run peru sync again, it does very little. Currently only a single command to check the status of the tree. This is an imporant part of the "put peru sync in your Makefile or at the top of your Bash script and then forget about it" strategy.

So if checking for git meant shelling out to git --version or similar, that wouldn't be ideal. Is there another way of checking that you had in mind?

from peru.