First passing tests for fs.watch(), use EventEmitter2 via bower

bower.json

@@ -2,6 +2,9 @@
   "name": "filer",
   "version": "0.0.4",
   "main": "dist/filer.js",
+  "dependencies": {
+    "eventemitter2": "~0.4.13"
+  },
   "devDependencies": {
     "mocha": "1.17.1",
     "chai": "1.9.0"

gruntfile.js

@@ -45,7 +45,8 @@ module.exports = function(grunt) {
         options: {
           paths: {
             "src": "../src",
-            "build": "../build"
+            "build": "../build",
+            "EventEmitter": "../bower_components/eventemitter2/lib/eventemitter2"
           },
           baseUrl: "lib",
           name: "build/almond",

lib/eventemitter.js

@@ -1,66 +0,0 @@
-define(function(require) {
-
-  // Based on https://github.com/diy/intercom.js/blob/master/lib/events.js
-  // Copyright 2012 DIY Co Apache License, Version 2.0
-  // http://www.apache.org/licenses/LICENSE-2.0
-
-  function removeItem(item, array) {
-    for (var i = array.length - 1; i >= 0; i--) {
-      if (array[i] === item) {
-        array.splice(i, 1);
-      }
-    }
-    return array;
-  }
-
-  function EventEmitter() {}
-
-  EventEmitter.createInterface = function(space) {
-    var methods = {};
-
-    methods.on = function(name, fn) {
-      if (typeof this[space] === 'undefined') {
-        this[space] = {};
-      }
-      if (!this[space].hasOwnProperty(name)) {
-        this[space][name] = [];
-      }
-      this[space][name].push(fn);
-    };
-
-    methods.off = function(name, fn) {
-      if (typeof this[space] === 'undefined') return;
-      if (this[space].hasOwnProperty(name)) {
-        removeItem(fn, this[space][name]);
-      }
-    };
-
-    methods.trigger = function(name) {
-      if (typeof this[space] !== 'undefined' && this[space].hasOwnProperty(name)) {
-        var args = Array.prototype.slice.call(arguments, 1);
-        for (var i = 0; i < this[space][name].length; i++) {
-          this[space][name][i].apply(this[space][name][i], args);
-        }
-      }
-    };
-
-    return methods;
-  };
-
-  var pvt = EventEmitter.createInterface('_handlers');
-  EventEmitter.prototype._on = pvt.on;
-  EventEmitter.prototype._off = pvt.off;
-  EventEmitter.prototype._trigger = pvt.trigger;
-
-  var pub = EventEmitter.createInterface('handlers');
-  EventEmitter.prototype.on = function() {
-    pub.on.apply(this, arguments);
-    Array.prototype.unshift.call(arguments, 'on');
-    this._trigger.apply(this, arguments);
-  };
-  EventEmitter.prototype.off = pub.off;
-  EventEmitter.prototype.trigger = pub.trigger;
-
-  return EventEmitter;
-
-});

lib/intercom.js

@@ -4,7 +4,7 @@ define(function(require) {
   // Copyright 2012 DIY Co Apache License, Version 2.0
   // http://www.apache.org/licenses/LICENSE-2.0
 
-  var EventEmitter = require('eventemitter');
+  var EventEmitter = require('EventEmitter');
   var guid = require('src/shared').guid;
 
   function throttle(delay, fn) {

src/fs.js

@@ -59,6 +59,7 @@ define(function(require) {
   var adapters = require('src/adapters/adapters');
   var Shell = require('src/shell');
   var Intercom = require('intercom');
+  var EventEmitter = require('EventEmitter');
 
   /*
    * DirectoryEntry
@@ -1551,6 +1552,45 @@ define(function(require) {
   }
 
 
+  /*
+   * FSWatcher based loosely on node.js' FSWatcher
+   * see https://github.com/joyent/node/blob/master/lib/fs.js
+   */
+  function FSWatcher() {
+    EventEmitter.call(this);
+    var self = this;
+    var recursive = false;
+    var filename;
+
+    function onchange(path) {
+      // Watch for exact filename, or parent path when recursive is true
+      if(filename === path || (recursive && filename.indexOf(path + '/') === 0)) {
+        self.emit('change', filename);
+      }
+    }
+
+    // We support, but ignore the second arg, which node.js uses.
+    self.start = function(filename_, persistent_, recursive_) {
+      if(isNullPath(filename)) {
+        throw new Error('Path must be a string without null bytes.');
+      }
+      recursive = recursive_ === true;
+      // TODO: get realpath for symlinks on filename...
+      filename = filename_;
+
+      var intercom = Intercom.getInstance();
+      intercom.on('change', onchange);
+    };
+
+    self.close = function() {
+      var intercom = Intercom.getInstance();
+      intercom.off('change', onchange);
+    };
+  }
+  FSWatcher.prototype = new EventEmitter();
+  FSWatcher.prototype.constructor = FSWatcher;
+
+
   /*
    * FileSystem
    *
@@ -1628,12 +1668,31 @@ define(function(require) {
       queue = null;
     }
 
+    // FileSystem watch events are broadcast between windows via intercom
+    var intercom = Intercom.getInstance();
+
+    // We support the optional `options` arg from node, but ignore it
+    this.watch = function(filename, options, listener) {
+      if(isNullPath(filename)) {
+        throw new Error('Path must be a string without null bytes.');
+      }
+      if(typeof options === 'function') {
+        listener = options;
+        options = {};
+      }
+      options = options || {};
+      listener = listener || nop;
+
+      var watcher = new FSWatcher();
+      watcher.start(filename, false, options.recursive);
+      watcher.addListener('change', listener);
+
+      return watcher;
+    };
+
     // Open file system storage provider
     provider.open(function(err, needsFormatting) {
       function complete(error) {
-        // FileSystem watch events are broadcast between windows via intercom
-        var intercom = Intercom.getInstance();
-
         // Wrap the provider so we can extend the context with fs flags, intercom.
         // From this point forward we won't call open again, so drop it.
         fs.provider = {

tests/require-config.js

@@ -58,7 +58,8 @@ var config = (function() {
       "spec": "../tests/spec",
       "bugs": "../tests/bugs",
       "util": "../tests/lib/test-utils",
-      "Filer": "../src/index"
+      "Filer": "../src/index",
+      "EventEmitter": "../bower_components/eventemitter2/lib/eventemitter2"
     },
     baseUrl: "../lib",
     optimize: "none",

tests/spec/fs.watch.spec.js

@@ -0,0 +1,39 @@
+define(["Filer", "util"], function(Filer, util) {
+
+  describe('fs.watch', function() {
+    beforeEach(util.setup);
+    afterEach(util.cleanup);
+
+    it('should be a function', function() {
+      var fs = util.fs();
+      expect(typeof fs.watch).to.equal('function');
+    });
+
+    it('should get a change event when writing a file', function(done) {
+      var fs = util.fs();
+
+      fs.watch('/myfile', function(filename) {
+        expect(filename).to.equal('/myfile');
+        done();
+      });
+
+      fs.writeFile('/myfile', 'data', function(error) {
+        if(error) throw error;
+      });
+    });
+
+    it('should get a change event when writing a file in a dir with recursive=true', function(done) {
+      var fs = util.fs();
+
+      fs.watch('/', { recursive: true }, function(filename) {
+        expect(filename).to.equal('/');
+        done();
+      });
+
+      fs.writeFile('/myfile', 'data', function(error) {
+        if(error) throw error;
+      });
+    });
+  });
+
+});

tests/test-manifest.js

@@ -34,6 +34,7 @@ define([
   "spec/path-resolution.spec",
   "spec/times.spec",
   "spec/time-flags.spec",
+  "spec/fs.watch.spec",
 
   // Filer.FileSystem.providers.*
   "spec/providers/providers.spec",