这个问题可以参考npm源码提供的说明，地址https://github.com/npm/npm/blob/master/lib/utils/completion.sh
#!/bin/bash
###-begin-npm-completion-###
#
# npm command completion script
#
# Installation: npm completion >> ~/.bashrc (or ~/.zshrc)
# Or, maybe: npm completion > /usr/local/etc/bash_completion.d/npm
#
按照注释头的做法
$ npm completion >> ~/.bashrc
$ source ~/.bashrc