node.jscoffeescriptnpmnode-modules

How to use executables from a package installed locally in node_modules?

How do I use a local version of a module in node.js. For example, in my app, I installed coffee-script:

npm install coffee-script

This installs it in ./node_modules and the coffee command is in ./node_modules/.bin/coffee. Is there a way to run this command when I'm in my project's main folder? I guess I'm looking for something similar to bundle exec in bundler. Basically, I'd like to specify a version of coffee-script that everyone involved with the project should use.

I know I can add the -g flag to install it globally so coffee works fine anywhere, but what if I wanted to have different versions of coffee per project?

Solution

  • For npm ⩾5.2.0 (update)

    As Seyeong Jeong points out in their answer below, since npm 5.2.0 you can use npx, which is more convenient:

    npx [command]

    For older versions npm <5.2.0 (old answer)

    The problem with putting

    ./node_modules/.bin

    into your PATH is that it only works when your current working directory is the root of your project directory structure (i.e. the location of node_modules)

    Independent of what your working directory is, you can get the path of locally installed binaries with

    npm bin

    To execute a locally installed coffee binary independent of where you are in the project directory hierarchy you can use this bash construct

    PATH=$(npm bin):$PATH coffee

    I aliased this to npm-exec

    alias npm-exec='PATH=$(npm bin):$PATH'

    So, now I can

    npm-exec coffee

    to run the correct copy of coffee no matter of where I am

    $ pwd
/Users/regular/project1

$ npm-exec which coffee
/Users/regular/project1/node_modules/.bin/coffee

$ cd lib/
$ npm-exec which coffee
/Users/regular/project1/node_modules/.bin/coffee

$ cd ~/project2
$ npm-exec which coffee
/Users/regular/project2/node_modules/.bin/coffee