1 files changed, 54 insertions, 0 deletions
diff --git a/deps/npm/node_modules/find-npm-prefix/find-prefix.js b/deps/npm/node_modules/find-npm-prefix/find-prefix.js
new file mode 100644
index 0000000000..089572ec11
--- /dev/null
+++ b/deps/npm/node_modules/find-npm-prefix/find-prefix.js
@@ -0,0 +1,54 @@
+'use strict'
+// try to find the most reasonable prefix to use
+
+module.exports = findPrefix
+
+const fs = require('fs')
+const path = require('path')
+const Bluebird = require('bluebird')
+const readdir = Bluebird.promisify(fs.readdir)
+
+function findPrefix (dir) {
+  return Bluebird.try(() => {
+    dir = path.resolve(dir)
+
+    // this is a weird special case where an infinite recurse of
+    // node_modules folders resolves to the level that contains the
+    // very first node_modules folder
+    let walkedUp = false
+    while (path.basename(dir) === 'node_modules') {
+      dir = path.dirname(dir)
+      walkedUp = true
+    }
+    if (walkedUp) return dir
+
+    return findPrefix_(dir)
+  })
+}
+
+function findPrefix_ (dir, original) {
+  if (!original) original = dir
+
+  const parent = path.dirname(dir)
+  // this is a platform independent way of checking if we're in the root
+  // directory
+  if (parent === dir) return original
+
+  return readdir(dir).then(files => {
+    if (files.indexOf('node_modules') !== -1 ||
+        files.indexOf('package.json') !== -1) {
+      return dir
+    }
+
+    return findPrefix_(parent, original)
+  }, er => {
+    // an error right away is a bad sign.
+    // unless the prefix was simply a non
+    // existent directory.
+    if (er && dir === original && er.code !== 'ENOENT') {
+      throw er
+    } else {
+      return original
+    }
+  })
+}