adir

Utility for recursive aggregation of directory trees. Useful for creating directory indices, searching by file attributes, performing calculations on a directory tree, building routing tables dynamically, etc.

Usage

 
const aggregate = require('adir'),
      tree      = {}
 
function onEntry(stats, subtree) {
    var name = stats.basename
 
    if (stats.isDirectory())
        return subtree[ name ] = {}
    else
        subtree[ name ] = stats.size
}
 
function done(err) {
    if (err)
        console.error(err.stack)
    else
        console.log(tree)
}
 
aggregate('./', onEntry, tree, done)
 

API

adir(path, onEntry, [initialValue], [callback]) ⇒ Promise
adir.fs: The file system interface to use.
adir.break: Reference used to signal the end of an aggregation branch.
adir.version: The version string from package manifest.

 
const fs   = require('fs'),
      adir = require('adir')
 
typeof adir === 'function'
adir.fs === fs
typeof adir.break === 'object'
typeof adir.version === 'string'
 
function onEntry(stats, value) {
    stats instanceof fs.Stats
    typeof stats.path === 'string'
    typeof stats.basename === 'string'
 
    value === 0
 
    return value
}
 
function callback(err) {
    err instanceof Error ||
    err === null
}
 
adir('./', onEntry, 0, callback) instanceof Promise
 

How It Works?

adir iterates over subdirectories of a folder and calls the given onEntry handler on each directory or file, taking an extended fs.Stats instance and the value previously returned in the last invocation of onEntry, or initialValue, if supplied. You can think of it like a kind of Array.prototype.reduce() except the reduction forks when it meets a directory.

 
const aggregate = require('adir')
 
function onEntry(stats, count) {
    if (stats.isDirectory())
        return count + 1
    else
        console.log(stats.path, 'has', count, 'parent directories')
}
 
aggregate('./', onEntry, 0)
 

If onEntry returns a Promise then it'll be awaited before the aggregation of the corresponding branch continues. See this for a working example.

Cancellation

The aggregation of a branch stops immediately if onEntry returns with adir.break (or the Promise returned by onEntry resolves with that value). This example shows that in action.

Compatibility

adir is compatible with Node 0.8 and above but a Promise implementation is required even if you're using the callback API only. Tested with bluebird.

Installation

With npm:

npm install adir

License

MIT