If you have a package on npm that you want to maintain, and want to use it in a different project, everytime you make a change to the code, you need to
npm publish, then in the consumer project,
npm update. Well not really.
In the package folder: (my_npm_package/)
> npm link
In the consuming project
> npm link my_npm_package
Now your consumer project is consuming the local version. Don't forget to publish your package though, for other consumers.
To remove link, in consumer project:
> npm unlink my_npm_package