npm install module in current directory

npm install installs packages either locally or globally:

• Locally: npm looks for an existing folder called node_modules in the current directory and creates a folder for each package you install in that folder. If it can’t find an existing node_modules folder here, it then looks through the current directory’s ancestors until it finds one. If it can’t find one, it creates one in the current directory.
• Globally: if you use the -g (global) option, the package is installed in a global location. This location varies per Linux distribution, but /usr/local/lib/node_modules/packagename is one example. CentOS7 uses /usr/lib/node_modules/packagename.

You should only use -g when the package is something you’d want to use as a command.

Just like how global variables are kind of gross, but also necessary
in some cases, global packages are important, but best avoided if not
needed.

In general, the rule of thumb is:

1. If you’re installing something that you want to use in your program,
   using require('whatever'), then install it locally, at the root of
   your project.
2. If you’re installing something that you want to use in
   your shell, on the command line or something, install it globally, so
   that its binaries end up in your PATH environment variable.

npm will not install a package’s files directly into the current directory.

However, this is actually a good thing. It keeps dependencies’ files separate from your app, and Node automatically searches the node_modules folder when you require something.