first commit

build/node_modules/npm-path/find-prefix.js

@@ -0,0 +1,73 @@
+var fs = require('fs')
+var path = require('path')
+
+module.exports = function (options, cb) {
+  return findPrefix(options.cwd, options.isSync, cb)
+}
+
+function readdir (p, isSync, fn) {
+  if (isSync) {
+    try {
+      var val = fs.readdirSync(p)
+    } catch (err) {
+      return fn(err)
+    }
+
+    return fn(null, val)
+  }
+
+  return fs.readdir(p, fn)
+}
+
+// try to find the most reasonable prefix to use
+function findPrefix (p, isSync, cb_) {
+  function cb (er, p) {
+    if (isSync) return cb_(er, p)
+    process.nextTick(function () {
+      cb_(er, p)
+    })
+  }
+
+  p = path.resolve(p)
+  // if there's no node_modules folder, then
+  // walk up until we hopefully find one.
+  // if none anywhere, then use cwd.
+  var walkedUp = false
+  while (path.basename(p) === 'node_modules') {
+    p = path.dirname(p)
+    walkedUp = true
+  }
+  if (walkedUp) return cb(null, p)
+
+  findPrefix_(p, p, isSync, cb)
+}
+
+function findPrefix_ (p, original, isSync, cb) {
+  if (p === '/' ||
+      (process.platform === 'win32' && p.match(/^[a-zA-Z]:(\\|\/)?$/))) {
+    return cb(null, original)
+  }
+
+  readdir(p, isSync, function (er, files) {
+    // an error right away is a bad sign.
+    // unless the prefix was simply a non
+    // existent directory.
+    if (er && p === original) {
+      if (er.code === 'ENOENT') return cb(null, original)
+      return cb(er)
+    }
+
+    // walked up too high or something.
+    if (er) return cb(null, original)
+
+    if (files.indexOf('node_modules') !== -1 ||
+        files.indexOf('package.json') !== -1) {
+      return cb(null, p)
+    }
+
+    var d = path.dirname(p)
+    if (d === p) return cb(null, original)
+
+    return findPrefix_(d, original, isSync, cb)
+  })
+}