Dependencies are the careful balance between modularity, reuse, and ease-of-use. When working with Nodejitsu (and node.js in general) dependencies are managed through the package.json dependencies property. Creating a package.json is an important step in node.js application comprehension. For more information on this checkout npm and our CLI tool jitsu, both of which will help you understand creating package.json files.

Making sure your package.json has all the right ingredients is important! Nodejitsu is happy to announce the release of a simple and elegant tool for determining and analyzing your dependencies, aptly named: require-analyzer. This post will walk you through how to use the library as well as outline our jitsu integration and upcoming npm integration.

Using require-analyzer

There are two distinct ways to use the require-analyzer library: from the command line or through code. The command line tool is designed to work with package.json files; make sure that you have created one for your project beforehand.

Lets take a look at how I used require-analyzer to analyze its own dependencies:

  $ require-analyzer
  info:  require-analyzer starting in /path/to/require-analyzer
  warn:  No dependencies found
  info:  Analyzing dependencies...
  info:  Done analyzing raw dependencies
  info:  Retrieved packages from npm
  info:  Additional dependencies found
  data:  {
  data:    async: '>= 0.1.8',
  data:    findit: '>= 0.0.3',
  data:    npm: '>= 0.3.18'
  data:  }
  info:  Updating /path/to/require-analyzer/package.json
  info:  require-analyzer updated package.json dependencies

If you're a power user (you know who you are) don't fret: the require-analyzer API is fully available through pure node.js code. The easiest way to use require-analyzer programmatically is through the .analyze() method. This method will use fs.stat() on the path supplied and attempt one of three options:

1. If it is a directory that has a package.json, analyze require statements from package.main
2. If it is a directory with no package.json analyze every .js or .coffee file in the directory tree
3. If it is a file, then analyze require statements from that individual file.

Lets dive into a quick sample usage:

  info:   Analyzing your application dependencies in bin/server
  info:   Found new dependencies
  data:   {
  data:       colors: '>= 0.5.0',
  data:       http-proxy: '>= 0.5.0',
  data:       loggly: '>= 0.3.2',
  data:       node-static: '>= 0.5.3',
  data:       optimist: '>= 0.1.9',
  data:       request: '>= 1.9.5',
  data:       winston: '>= 0.2.7'
  data:   }
  warn:   New dependencies will be added for you automatically.