node_modules

2 files changed, 877 insertions, 0 deletions

diff --git a/node_modules/chokidar/lib/fsevents-handler.js b/node_modules/chokidar/lib/fsevents-handler.js
new file mode 100644
index 000000000..dbf6adeed
--- /dev/null
+++ b/node_modules/chokidar/lib/fsevents-handler.js
@@ -0,0 +1,396 @@
+'use strict';
+
+var fs = require('fs');
+var sysPath = require('path');
+var readdirp = require('readdirp');
+var fsevents;
+try { fsevents = require('fsevents'); } catch (error) {}
+
+// fsevents instance helper functions
+
+// object to hold per-process fsevents instances
+// (may be shared across chokidar FSWatcher instances)
+var FSEventsWatchers = Object.create(null);
+
+// Threshold of duplicate path prefixes at which to start
+// consolidating going forward
+var consolidateThreshhold = 10;
+
+// Private function: Instantiates the fsevents interface
+
+// * path       - string, path to be watched
+// * callback   - function, called when fsevents is bound and ready
+
+// Returns new fsevents instance
+function createFSEventsInstance(path, callback) {
+  return (new fsevents(path)).on('fsevent', callback).start();
+}
+
+// Private function: Instantiates the fsevents interface or binds listeners
+// to an existing one covering the same file tree
+
+// * path       - string, path to be watched
+// * realPath   - string, real path (in case of symlinks)
+// * listener   - function, called when fsevents emits events
+// * rawEmitter - function, passes data to listeners of the 'raw' event
+
+// Returns close function
+function setFSEventsListener(path, realPath, listener, rawEmitter) {
+  var watchPath = sysPath.extname(path) ? sysPath.dirname(path) : path;
+  var watchContainer;
+  var parentPath = sysPath.dirname(watchPath);
+
+  // If we've accumulated a substantial number of paths that
+  // could have been consolidated by watching one directory
+  // above the current one, create a watcher on the parent
+  // path instead, so that we do consolidate going forward.
+  if (couldConsolidate(parentPath)) {
+    watchPath = parentPath;
+  }
+
+  var resolvedPath = sysPath.resolve(path);
+  var hasSymlink = resolvedPath !== realPath;
+  function filteredListener(fullPath, flags, info) {
+    if (hasSymlink) fullPath = fullPath.replace(realPath, resolvedPath);
+    if (
+      fullPath === resolvedPath ||
+      !fullPath.indexOf(resolvedPath + sysPath.sep)
+    ) listener(fullPath, flags, info);
+  }
+
+  // check if there is already a watcher on a parent path
+  // modifies `watchPath` to the parent path when it finds a match
+  function watchedParent() {
+    return Object.keys(FSEventsWatchers).some(function(watchedPath) {
+      // condition is met when indexOf returns 0
+      if (!realPath.indexOf(sysPath.resolve(watchedPath) + sysPath.sep)) {
+        watchPath = watchedPath;
+        return true;
+      }
+    });
+  }
+
+  if (watchPath in FSEventsWatchers || watchedParent()) {
+    watchContainer = FSEventsWatchers[watchPath];
+    watchContainer.listeners.push(filteredListener);
+  } else {
+    watchContainer = FSEventsWatchers[watchPath] = {
+      listeners: [filteredListener],
+      rawEmitters: [rawEmitter],
+      watcher: createFSEventsInstance(watchPath, function(fullPath, flags) {
+        var info = fsevents.getInfo(fullPath, flags);
+        watchContainer.listeners.forEach(function(listener) {
+          listener(fullPath, flags, info);
+        });
+        watchContainer.rawEmitters.forEach(function(emitter) {
+          emitter(info.event, fullPath, info);
+        });
+      })
+    };
+  }
+  var listenerIndex = watchContainer.listeners.length - 1;
+
+  // removes this instance's listeners and closes the underlying fsevents
+  // instance if there are no more listeners left
+  return function close() {
+    delete watchContainer.listeners[listenerIndex];
+    delete watchContainer.rawEmitters[listenerIndex];
+    if (!Object.keys(watchContainer.listeners).length) {
+      watchContainer.watcher.stop();
+      delete FSEventsWatchers[watchPath];
+    }
+  };
+}
+
+// Decide whether or not we should start a new higher-level
+// parent watcher
+function couldConsolidate(path) {
+  var keys = Object.keys(FSEventsWatchers);
+  var count = 0;
+
+  for (var i = 0, len = keys.length; i < len; ++i) {
+    var watchPath = keys[i];
+    if (watchPath.indexOf(path) === 0) {
+      count++;
+      if (count >= consolidateThreshhold) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+// returns boolean indicating whether fsevents can be used
+function canUse() {
+  return fsevents && Object.keys(FSEventsWatchers).length < 128;
+}
+
+// determines subdirectory traversal levels from root to path
+function depth(path, root) {
+  var i = 0;
+  while (!path.indexOf(root) && (path = sysPath.dirname(path)) !== root) i++;
+  return i;
+}
+
+// fake constructor for attaching fsevents-specific prototype methods that
+// will be copied to FSWatcher's prototype
+function FsEventsHandler() {}
+
+// Private method: Handle symlinks encountered during directory scan
+
+// * watchPath  - string, file/dir path to be watched with fsevents
+// * realPath   - string, real path (in case of symlinks)
+// * transform  - function, path transformer
+// * globFilter - function, path filter in case a glob pattern was provided
+
+// Returns close function for the watcher instance
+FsEventsHandler.prototype._watchWithFsEvents =
+function(watchPath, realPath, transform, globFilter) {
+  if (this._isIgnored(watchPath)) return;
+  var watchCallback = function(fullPath, flags, info) {
+    if (
+      this.options.depth !== undefined &&
+      depth(fullPath, realPath) > this.options.depth
+    ) return;
+    var path = transform(sysPath.join(
+      watchPath, sysPath.relative(watchPath, fullPath)
+    ));
+    if (globFilter && !globFilter(path)) return;
+    // ensure directories are tracked
+    var parent = sysPath.dirname(path);
+    var item = sysPath.basename(path);
+    var watchedDir = this._getWatchedDir(
+      info.type === 'directory' ? path : parent
+    );
+    var checkIgnored = function(stats) {
+      if (this._isIgnored(path, stats)) {
+        this._ignoredPaths[path] = true;
+        if (stats && stats.isDirectory()) {
+          this._ignoredPaths[path + '/**/*'] = true;
+        }
+        return true;
+      } else {
+        delete this._ignoredPaths[path];
+        delete this._ignoredPaths[path + '/**/*'];
+      }
+    }.bind(this);
+
+    var handleEvent = function(event) {
+      if (checkIgnored()) return;
+
+      if (event === 'unlink') {
+        // suppress unlink events on never before seen files
+        if (info.type === 'directory' || watchedDir.has(item)) {
+          this._remove(parent, item);
+        }
+      } else {
+        if (event === 'add') {
+          // track new directories
+          if (info.type === 'directory') this._getWatchedDir(path);
+
+          if (info.type === 'symlink' && this.options.followSymlinks) {
+            // push symlinks back to the top of the stack to get handled
+            var curDepth = this.options.depth === undefined ?
+              undefined : depth(fullPath, realPath) + 1;
+            return this._addToFsEvents(path, false, true, curDepth);
+          } else {
+            // track new paths
+            // (other than symlinks being followed, which will be tracked soon)
+            this._getWatchedDir(parent).add(item);
+          }
+        }
+        var eventName = info.type === 'directory' ? event + 'Dir' : event;
+        this._emit(eventName, path);
+        if (eventName === 'addDir') this._addToFsEvents(path, false, true);
+      }
+    }.bind(this);
+
+    function addOrChange() {
+      handleEvent(watchedDir.has(item) ? 'change' : 'add');
+    }
+    function checkFd() {
+      fs.open(path, 'r', function(error, fd) {
+        if (fd) fs.close(fd);
+        error && error.code !== 'EACCES' ?
+          handleEvent('unlink') : addOrChange();
+      });
+    }
+    // correct for wrong events emitted
+    var wrongEventFlags = [
+      69888, 70400, 71424, 72704, 73472, 131328, 131840, 262912
+    ];
+    if (wrongEventFlags.indexOf(flags) !== -1 || info.event === 'unknown') {
+      if (typeof this.options.ignored === 'function') {
+        fs.stat(path, function(error, stats) {
+          if (checkIgnored(stats)) return;
+          stats ? addOrChange() : handleEvent('unlink');
+        });
+      } else {
+        checkFd();
+      }
+    } else {
+      switch (info.event) {
+      case 'created':
+      case 'modified':
+        return addOrChange();
+      case 'deleted':
+      case 'moved':
+        return checkFd();
+      }
+    }
+  }.bind(this);
+
+  var closer = setFSEventsListener(
+    watchPath,
+    realPath,
+    watchCallback,
+    this.emit.bind(this, 'raw')
+  );
+
+  this._emitReady();
+  return closer;
+};
+
+// Private method: Handle symlinks encountered during directory scan
+
+// * linkPath   - string, path to symlink
+// * fullPath   - string, absolute path to the symlink
+// * transform  - function, pre-existing path transformer
+// * curDepth   - int, level of subdirectories traversed to where symlink is
+
+// Returns nothing
+FsEventsHandler.prototype._handleFsEventsSymlink =
+function(linkPath, fullPath, transform, curDepth) {
+  // don't follow the same symlink more than once
+  if (this._symlinkPaths[fullPath]) return;
+  else this._symlinkPaths[fullPath] = true;
+
+  this._readyCount++;
+
+  fs.realpath(linkPath, function(error, linkTarget) {
+    if (this._handleError(error) || this._isIgnored(linkTarget)) {
+      return this._emitReady();
+    }
+
+    this._readyCount++;
+
+    // add the linkTarget for watching with a wrapper for transform
+    // that causes emitted paths to incorporate the link's path
+    this._addToFsEvents(linkTarget || linkPath, function(path) {
+      var dotSlash = '.' + sysPath.sep;
+      var aliasedPath = linkPath;
+      if (linkTarget && linkTarget !== dotSlash) {
+        aliasedPath = path.replace(linkTarget, linkPath);
+      } else if (path !== dotSlash) {
+        aliasedPath = sysPath.join(linkPath, path);
+      }
+      return transform(aliasedPath);
+    }, false, curDepth);
+  }.bind(this));
+};
+
+// Private method: Handle added path with fsevents
+
+// * path       - string, file/directory path or glob pattern
+// * transform  - function, converts working path to what the user expects
+// * forceAdd   - boolean, ensure add is emitted
+// * priorDepth - int, level of subdirectories already traversed
+
+// Returns nothing
+FsEventsHandler.prototype._addToFsEvents =
+function(path, transform, forceAdd, priorDepth) {
+
+  // applies transform if provided, otherwise returns same value
+  var processPath = typeof transform === 'function' ?
+    transform : function(val) { return val; };
+
+  var emitAdd = function(newPath, stats) {
+    var pp = processPath(newPath);
+    var isDir = stats.isDirectory();
+    var dirObj = this._getWatchedDir(sysPath.dirname(pp));
+    var base = sysPath.basename(pp);
+
+    // ensure empty dirs get tracked
+    if (isDir) this._getWatchedDir(pp);
+
+    if (dirObj.has(base)) return;
+    dirObj.add(base);
+
+    if (!this.options.ignoreInitial || forceAdd === true) {
+      this._emit(isDir ? 'addDir' : 'add', pp, stats);
+    }
+  }.bind(this);
+
+  var wh = this._getWatchHelpers(path);
+
+  // evaluate what is at the path we're being asked to watch
+  fs[wh.statMethod](wh.watchPath, function(error, stats) {
+    if (this._handleError(error) || this._isIgnored(wh.watchPath, stats)) {
+      this._emitReady();
+      return this._emitReady();
+    }
+
+    if (stats.isDirectory()) {
+      // emit addDir unless this is a glob parent
+      if (!wh.globFilter) emitAdd(processPath(path), stats);
+
+      // don't recurse further if it would exceed depth setting
+      if (priorDepth && priorDepth > this.options.depth) return;
+
+      // scan the contents of the dir
+      readdirp({
+        root: wh.watchPath,
+        entryType: 'all',
+        fileFilter: wh.filterPath,
+        directoryFilter: wh.filterDir,
+        lstat: true,
+        depth: this.options.depth - (priorDepth || 0)
+      }).on('data', function(entry) {
+        // need to check filterPath on dirs b/c filterDir is less restrictive
+        if (entry.stat.isDirectory() && !wh.filterPath(entry)) return;
+
+        var joinedPath = sysPath.join(wh.watchPath, entry.path);
+        var fullPath = entry.fullPath;
+
+        if (wh.followSymlinks && entry.stat.isSymbolicLink()) {
+          // preserve the current depth here since it can't be derived from
+          // real paths past the symlink
+          var curDepth = this.options.depth === undefined ?
+            undefined : depth(joinedPath, sysPath.resolve(wh.watchPath)) + 1;
+
+          this._handleFsEventsSymlink(joinedPath, fullPath, processPath, curDepth);
+        } else {
+          emitAdd(joinedPath, entry.stat);
+        }
+      }.bind(this)).on('error', function() {
+        // Ignore readdirp errors
+      }).on('end', this._emitReady);
+    } else {
+      emitAdd(wh.watchPath, stats);
+      this._emitReady();
+    }
+  }.bind(this));
+
+  if (this.options.persistent && forceAdd !== true) {
+    var initWatch = function(error, realPath) {
+      var closer = this._watchWithFsEvents(
+        wh.watchPath,
+        sysPath.resolve(realPath || wh.watchPath),
+        processPath,
+        wh.globFilter
+      );
+      if (closer) this._closers[path] = closer;
+    }.bind(this);
+
+    if (typeof transform === 'function') {
+      // realpath has already been resolved
+      initWatch();
+    } else {
+      fs.realpath(wh.watchPath, initWatch);
+    }
+  }
+};
+
+module.exports = FsEventsHandler;
+module.exports.canUse = canUse;
diff --git a/node_modules/chokidar/lib/nodefs-handler.js b/node_modules/chokidar/lib/nodefs-handler.js
new file mode 100644
index 000000000..9d05b6fcb
--- /dev/null
+++ b/node_modules/chokidar/lib/nodefs-handler.js
@@ -0,0 +1,481 @@
+'use strict';
+
+var fs = require('fs');
+var sysPath = require('path');
+var readdirp = require('readdirp');
+var isBinaryPath = require('is-binary-path');
+
+// fs.watch helpers
+
+// object to hold per-process fs.watch instances
+// (may be shared across chokidar FSWatcher instances)
+var FsWatchInstances = Object.create(null);
+
+// Private function: Instantiates the fs.watch interface
+
+// * path       - string, path to be watched
+// * options    - object, options to be passed to fs.watch
+// * listener   - function, main event handler
+// * errHandler - function, handler which emits info about errors
+// * emitRaw    - function, handler which emits raw event data
+
+// Returns new fsevents instance
+function createFsWatchInstance(path, options, listener, errHandler, emitRaw) {
+  var handleEvent = function(rawEvent, evPath) {
+    listener(path);
+    emitRaw(rawEvent, evPath, {watchedPath: path});
+
+    // emit based on events occuring for files from a directory's watcher in
+    // case the file's watcher misses it (and rely on throttling to de-dupe)
+    if (evPath && path !== evPath) {
+      fsWatchBroadcast(
+        sysPath.resolve(path, evPath), 'listeners', sysPath.join(path, evPath)
+      );
+    }
+  };
+  try {
+    return fs.watch(path, options, handleEvent);
+  } catch (error) {
+    errHandler(error);
+  }
+}
+
+// Private function: Helper for passing fs.watch event data to a
+// collection of listeners
+
+// * fullPath   - string, absolute path bound to the fs.watch instance
+// * type       - string, listener type
+// * val[1..3]  - arguments to be passed to listeners
+
+// Returns nothing
+function fsWatchBroadcast(fullPath, type, val1, val2, val3) {
+  if (!FsWatchInstances[fullPath]) return;
+  FsWatchInstances[fullPath][type].forEach(function(listener) {
+    listener(val1, val2, val3);
+  });
+}
+
+// Private function: Instantiates the fs.watch interface or binds listeners
+// to an existing one covering the same file system entry
+
+// * path       - string, path to be watched
+// * fullPath   - string, absolute path
+// * options    - object, options to be passed to fs.watch
+// * handlers   - object, container for event listener functions
+
+// Returns close function
+function setFsWatchListener(path, fullPath, options, handlers) {
+  var listener = handlers.listener;
+  var errHandler = handlers.errHandler;
+  var rawEmitter = handlers.rawEmitter;
+  var container = FsWatchInstances[fullPath];
+  var watcher;
+  if (!options.persistent) {
+    watcher = createFsWatchInstance(
+      path, options, listener, errHandler, rawEmitter
+    );
+    return watcher.close.bind(watcher);
+  }
+  if (!container) {
+    watcher = createFsWatchInstance(
+      path,
+      options,
+      fsWatchBroadcast.bind(null, fullPath, 'listeners'),
+      errHandler, // no need to use broadcast here
+      fsWatchBroadcast.bind(null, fullPath, 'rawEmitters')
+    );
+    if (!watcher) return;
+    var broadcastErr = fsWatchBroadcast.bind(null, fullPath, 'errHandlers');
+    watcher.on('error', function(error) {
+      // Workaround for https://github.com/joyent/node/issues/4337
+      if (process.platform === 'win32' && error.code === 'EPERM') {
+        fs.open(path, 'r', function(err, fd) {
+          if (fd) fs.close(fd);
+          if (!err) broadcastErr(error);
+        });
+      } else {
+        broadcastErr(error);
+      }
+    });
+    container = FsWatchInstances[fullPath] = {
+      listeners: [listener],
+      errHandlers: [errHandler],
+      rawEmitters: [rawEmitter],
+      watcher: watcher
+    };
+  } else {
+    container.listeners.push(listener);
+    container.errHandlers.push(errHandler);
+    container.rawEmitters.push(rawEmitter);
+  }
+  var listenerIndex = container.listeners.length - 1;
+
+  // removes this instance's listeners and closes the underlying fs.watch
+  // instance if there are no more listeners left
+  return function close() {
+    delete container.listeners[listenerIndex];
+    delete container.errHandlers[listenerIndex];
+    delete container.rawEmitters[listenerIndex];
+    if (!Object.keys(container.listeners).length) {
+      container.watcher.close();
+      delete FsWatchInstances[fullPath];
+    }
+  };
+}
+
+// fs.watchFile helpers
+
+// object to hold per-process fs.watchFile instances
+// (may be shared across chokidar FSWatcher instances)
+var FsWatchFileInstances = Object.create(null);
+
+// Private function: Instantiates the fs.watchFile interface or binds listeners
+// to an existing one covering the same file system entry
+
+// * path       - string, path to be watched
+// * fullPath   - string, absolute path
+// * options    - object, options to be passed to fs.watchFile
+// * handlers   - object, container for event listener functions
+
+// Returns close function
+function setFsWatchFileListener(path, fullPath, options, handlers) {
+  var listener = handlers.listener;
+  var rawEmitter = handlers.rawEmitter;
+  var container = FsWatchFileInstances[fullPath];
+  var listeners = [];
+  var rawEmitters = [];
+  if (
+    container && (
+      container.options.persistent < options.persistent ||
+      container.options.interval > options.interval
+    )
+  ) {
+    // "Upgrade" the watcher to persistence or a quicker interval.
+    // This creates some unlikely edge case issues if the user mixes
+    // settings in a very weird way, but solving for those cases
+    // doesn't seem worthwhile for the added complexity.
+    listeners = container.listeners;
+    rawEmitters = container.rawEmitters;
+    fs.unwatchFile(fullPath);
+    container = false;
+  }
+  if (!container) {
+    listeners.push(listener);
+    rawEmitters.push(rawEmitter);
+    container = FsWatchFileInstances[fullPath] = {
+      listeners: listeners,
+      rawEmitters: rawEmitters,
+      options: options,
+      watcher: fs.watchFile(fullPath, options, function(curr, prev) {
+        container.rawEmitters.forEach(function(rawEmitter) {
+          rawEmitter('change', fullPath, {curr: curr, prev: prev});
+        });
+        var currmtime = curr.mtime.getTime();
+        if (curr.size !== prev.size || currmtime > prev.mtime.getTime() || currmtime === 0) {
+          container.listeners.forEach(function(listener) {
+            listener(path, curr);
+          });
+        }
+      })
+    };
+  } else {
+    container.listeners.push(listener);
+    container.rawEmitters.push(rawEmitter);
+  }
+  var listenerIndex = container.listeners.length - 1;
+
+  // removes this instance's listeners and closes the underlying fs.watchFile
+  // instance if there are no more listeners left
+  return function close() {
+    delete container.listeners[listenerIndex];
+    delete container.rawEmitters[listenerIndex];
+    if (!Object.keys(container.listeners).length) {
+      fs.unwatchFile(fullPath);
+      delete FsWatchFileInstances[fullPath];
+    }
+  };
+}
+
+// fake constructor for attaching nodefs-specific prototype methods that
+// will be copied to FSWatcher's prototype
+function NodeFsHandler() {}
+
+// Private method: Watch file for changes with fs.watchFile or fs.watch.
+
+// * path     - string, path to file or directory.
+// * listener - function, to be executed on fs change.
+
+// Returns close function for the watcher instance
+NodeFsHandler.prototype._watchWithNodeFs =
+function(path, listener) {
+  var directory = sysPath.dirname(path);
+  var basename = sysPath.basename(path);
+  var parent = this._getWatchedDir(directory);
+  parent.add(basename);
+  var absolutePath = sysPath.resolve(path);
+  var options = {persistent: this.options.persistent};
+  if (!listener) listener = Function.prototype; // empty function
+
+  var closer;
+  if (this.options.usePolling) {
+    options.interval = this.enableBinaryInterval && isBinaryPath(basename) ?
+      this.options.binaryInterval : this.options.interval;
+    closer = setFsWatchFileListener(path, absolutePath, options, {
+      listener: listener,
+      rawEmitter: this.emit.bind(this, 'raw')
+    });
+  } else {
+    closer = setFsWatchListener(path, absolutePath, options, {
+      listener: listener,
+      errHandler: this._handleError.bind(this),
+      rawEmitter: this.emit.bind(this, 'raw')
+    });
+  }
+  return closer;
+};
+
+// Private method: Watch a file and emit add event if warranted
+
+// * file       - string, the file's path
+// * stats      - object, result of fs.stat
+// * initialAdd - boolean, was the file added at watch instantiation?
+// * callback   - function, called when done processing as a newly seen file
+
+// Returns close function for the watcher instance
+NodeFsHandler.prototype._handleFile =
+function(file, stats, initialAdd, callback) {
+  var dirname = sysPath.dirname(file);
+  var basename = sysPath.basename(file);
+  var parent = this._getWatchedDir(dirname);
+
+  // if the file is already being watched, do nothing
+  if (parent.has(basename)) return callback();
+
+  // kick off the watcher
+  var closer = this._watchWithNodeFs(file, function(path, newStats) {
+    if (!this._throttle('watch', file, 5)) return;
+    if (!newStats || newStats && newStats.mtime.getTime() === 0) {
+      fs.stat(file, function(error, newStats) {
+        // Fix issues where mtime is null but file is still present
+        if (error) {
+          this._remove(dirname, basename);
+        } else {
+          this._emit('change', file, newStats);
+        }
+      }.bind(this));
+    // add is about to be emitted if file not already tracked in parent
+    } else if (parent.has(basename)) {
+      this._emit('change', file, newStats);
+    }
+  }.bind(this));
+
+  // emit an add event if we're supposed to
+  if (!(initialAdd && this.options.ignoreInitial)) {
+    if (!this._throttle('add', file, 0)) return;
+    this._emit('add', file, stats);
+  }
+
+  if (callback) callback();
+  return closer;
+};
+
+// Private method: Handle symlinks encountered while reading a dir
+
+// * entry      - object, entry object returned by readdirp
+// * directory  - string, path of the directory being read
+// * path       - string, path of this item
+// * item       - string, basename of this item
+
+// Returns true if no more processing is needed for this entry.
+NodeFsHandler.prototype._handleSymlink =
+function(entry, directory, path, item) {
+  var full = entry.fullPath;
+  var dir = this._getWatchedDir(directory);
+
+  if (!this.options.followSymlinks) {
+    // watch symlink directly (don't follow) and detect changes
+    this._readyCount++;
+    fs.realpath(path, function(error, linkPath) {
+      if (dir.has(item)) {
+        if (this._symlinkPaths[full] !== linkPath) {
+          this._symlinkPaths[full] = linkPath;
+          this._emit('change', path, entry.stat);
+        }
+      } else {
+        dir.add(item);
+        this._symlinkPaths[full] = linkPath;
+        this._emit('add', path, entry.stat);
+      }
+      this._emitReady();
+    }.bind(this));
+    return true;
+  }
+
+  // don't follow the same symlink more than once
+  if (this._symlinkPaths[full]) return true;
+  else this._symlinkPaths[full] = true;
+};
+
+// Private method: Read directory to add / remove files from `@watched` list
+// and re-read it on change.
+
+// * dir        - string, fs path.
+// * stats      - object, result of fs.stat
+// * initialAdd - boolean, was the file added at watch instantiation?
+// * depth      - int, depth relative to user-supplied path
+// * target     - string, child path actually targeted for watch
+// * wh         - object, common watch helpers for this path
+// * callback   - function, called when dir scan is complete
+
+// Returns close function for the watcher instance
+NodeFsHandler.prototype._handleDir =
+function(dir, stats, initialAdd, depth, target, wh, callback) {
+  var parentDir = this._getWatchedDir(sysPath.dirname(dir));
+  var tracked = parentDir.has(sysPath.basename(dir));
+  if (!(initialAdd && this.options.ignoreInitial) && !target && !tracked) {
+    if (!wh.hasGlob || wh.globFilter(dir)) this._emit('addDir', dir, stats);
+  }
+
+  // ensure dir is tracked (harmless if redundant)
+  parentDir.add(sysPath.basename(dir));
+  this._getWatchedDir(dir);
+
+  var read = function(directory, initialAdd, done) {
+    // Normalize the directory name on Windows
+    directory = sysPath.join(directory, '');
+
+    if (!wh.hasGlob) {
+      var throttler = this._throttle('readdir', directory, 1000);
+      if (!throttler) return;
+    }
+
+    var previous = this._getWatchedDir(wh.path);
+    var current = [];
+
+    readdirp({
+      root: directory,
+      entryType: 'all',
+      fileFilter: wh.filterPath,
+      directoryFilter: wh.filterDir,
+      depth: 0,
+      lstat: true
+    }).on('data', function(entry) {
+      var item = entry.path;
+      var path = sysPath.join(directory, item);
+      current.push(item);
+
+      if (entry.stat.isSymbolicLink() &&
+        this._handleSymlink(entry, directory, path, item)) return;
+
+      // Files that present in current directory snapshot
+      // but absent in previous are added to watch list and
+      // emit `add` event.
+      if (item === target || !target && !previous.has(item)) {
+        this._readyCount++;
+
+        // ensure relativeness of path is preserved in case of watcher reuse
+        path = sysPath.join(dir, sysPath.relative(dir, path));
+
+        this._addToNodeFs(path, initialAdd, wh, depth + 1);
+      }
+    }.bind(this)).on('end', function() {
+      if (throttler) throttler.clear();
+      if (done) done();
+
+      // Files that absent in current directory snapshot
+      // but present in previous emit `remove` event
+      // and are removed from @watched[directory].
+      previous.children().filter(function(item) {
+        return item !== directory &&
+          current.indexOf(item) === -1 &&
+          // in case of intersecting globs;
+          // a path may have been filtered out of this readdir, but
+          // shouldn't be removed because it matches a different glob
+          (!wh.hasGlob || wh.filterPath({
+            fullPath: sysPath.resolve(directory, item)
+          }));
+      }).forEach(function(item) {
+        this._remove(directory, item);
+      }, this);
+    }.bind(this)).on('error', this._handleError.bind(this));
+  }.bind(this);
+
+  var closer;
+
+  if (this.options.depth == null || depth <= this.options.depth) {
+    if (!target) read(dir, initialAdd, callback);
+    closer = this._watchWithNodeFs(dir, function(dirPath, stats) {
+      // if current directory is removed, do nothing
+      if (stats && stats.mtime.getTime() === 0) return;
+
+      read(dirPath, false);
+    });
+  } else {
+    callback();
+  }
+  return closer;
+};
+
+// Private method: Handle added file, directory, or glob pattern.
+// Delegates call to _handleFile / _handleDir after checks.
+
+// * path       - string, path to file or directory.
+// * initialAdd - boolean, was the file added at watch instantiation?
+// * depth      - int, depth relative to user-supplied path
+// * target     - string, child path actually targeted for watch
+// * callback   - function, indicates whether the path was found or not
+
+// Returns nothing
+NodeFsHandler.prototype._addToNodeFs =
+function(path, initialAdd, priorWh, depth, target, callback) {
+  if (!callback) callback = Function.prototype;
+  var ready = this._emitReady;
+  if (this._isIgnored(path) || this.closed) {
+    ready();
+    return callback(null, false);
+  }
+
+  var wh = this._getWatchHelpers(path, depth);
+  if (!wh.hasGlob && priorWh) {
+    wh.hasGlob = priorWh.hasGlob;
+    wh.globFilter = priorWh.globFilter;
+    wh.filterPath = priorWh.filterPath;
+    wh.filterDir = priorWh.filterDir;
+  }
+
+  // evaluate what is at the path we're being asked to watch
+  fs[wh.statMethod](wh.watchPath, function(error, stats) {
+    if (this._handleError(error)) return callback(null, path);
+    if (this._isIgnored(wh.watchPath, stats)) {
+      ready();
+      return callback(null, false);
+    }
+
+    var initDir = function(dir, target) {
+      return this._handleDir(dir, stats, initialAdd, depth, target, wh, ready);
+    }.bind(this);
+
+    var closer;
+    if (stats.isDirectory()) {
+      closer = initDir(wh.watchPath, target);
+    } else if (stats.isSymbolicLink()) {
+      var parent = sysPath.dirname(wh.watchPath);
+      this._getWatchedDir(parent).add(wh.watchPath);
+      this._emit('add', wh.watchPath, stats);
+      closer = initDir(parent, path);
+
+      // preserve this symlink's target path
+      fs.realpath(path, function(error, targetPath) {
+        this._symlinkPaths[sysPath.resolve(path)] = targetPath;
+        ready();
+      }.bind(this));
+    } else {
+      closer = this._handleFile(wh.watchPath, stats, initialAdd, ready);
+    }
+
+    if (closer) this._closers[path] = closer;
+    callback(null, false);
+  }.bind(this));
+};
+
+module.exports = NodeFsHandler;