I'm working on a project creation template create-esm and it would be great to be able to detect that npx invoked it so that I can defer to npm init, instead of say, yarn init.

My guess is that this could be done through an environment variable that is set for the executed child process.

Update:

On MacOS at least the process.env._ variable holds the executing path
'/Users/jdalton/.nvm/versions/node/v9.9.0/bin/npx'

I'm currently looking into process.ppid and pidtree.

Update:

Ah, it looks like NPX_CLI_JS is set! ❤️