npm explore <pkg> [ -- <cmd>]
Spawn a subshell in the directory of the installed package specified.
If a command is specified, then it is run in the subshell, which then immediately terminates.
This is particularly handy in the case of git submodules in the node_modules folder:
npm explore some-dependency -- git pull origin master
Note that the package is not automatically rebuilt afterwards, so be sure to use npm rebuild <pkg> if you make any changes.
The shell to run for the npm explore command.