node package manager



Read the contents of node_modules.


var rpt = require ('read-package-tree')
rpt('/path/to/pkg/root', function (node, kidName) {
  // optional filter function– if included, each package folder found is passed to 
  // it to see if it should be included in the final tree 
  // node is what we're adding children to 
  // kidName is the directory name of the module we're considering adding 
  // return true -> include, false -> skip 
}, function (er, data) {
  // er means that something didn't work. 
  // data is a structure like: 
  // { 
  //   package: <package.json data, or an empty object> 
  // defaults to `basename(path)` 
  //   children: [ <more things like this> ] 
  //   parent: <thing that has this in its children property, or null> 
  //   path: <path loaded> 
  //   realpath: <the real path on disk> 
  //   isLink: <set if this is a Link> 
  //   target: <if a Link, then this is the actual Node> 
  //   error: <if set, the error we got loading/parsing the package.json> 
  // } 

That's it. It doesn't figure out if dependencies are met, it doesn't mutate package.json data objects (beyond what read-package-json already does), it doesn't limit its search to include/exclude devDependencies, or anything else.

Just follows the links in the node_modules hierarchy and reads the package.json files it finds therein.

Symbolic Links

When there are symlinks to packages in the node_modules hierarchy, a Link object will be created, with a target that is a Node object.

For the most part, you can treat Link objects just the same as Node objects. But if your tree-walking program needs to treat symlinks differently from normal folders, then make sure to check the object.

In a given read-package-tree run, a specific path will always correspond to a single object, and a specific realpath will always correspond to a single Node object. This means that you may not be able to pass the resulting data object to JSON.stringify, because it may contain cycles.


Errors parsing or finding a package.json in node_modules will result in a node with the error property set. We will still find deeper node_modules if any exist. Prior to 5.0.0 these aborted tree reading with an error callback.

Only a few classes of errors are fatal (result in an error callback):

  • If the top level location is entirely missing, that will error.
  • if fs.realpath returns an error for any path its trying to resolve.