read-package-tree

Read the contents of node_modules.

# USAGE

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>
// package.name: 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>
// }
})
// or promise-style
rpt('/path/to/pkg/root').then(data => { ... })

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

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.