[Events] [SimpleEmitter] added testing helpers

src/kibana/factories/events.js

@@ -2,10 +2,10 @@ define(function (require) {
   var _ = require('lodash');
 
   return function EventsProvider(Private, Promise, Notifier) {
-    var BaseObject = Private(require('factories/base_object'));
+    var SimpleEmitter = require('utils/SimpleEmitter');
     var notify = new Notifier({ location: 'EventEmitter' });
 
-    _(Events).inherits(BaseObject);
+    _(Events).inherits(SimpleEmitter);
     function Events() {
       Events.Super.call(this);
       this._listeners = {};
@@ -89,6 +89,16 @@ define(function (require) {
       });
     };
 
+    /**
+     * Get a list of the handler functions for a specific event
+     *
+     * @param  {string} name
+     * @return {array[function]}
+     */
+    Events.prototype.listeners = function (name) {
+      return _.pluck(this._listeners[name], 'handler');
+    };
+
     return Events;
   };
 });

src/kibana/utils/SimpleEmitter.js

@@ -1,5 +1,6 @@
 define(function (require) {
   var _ = require('lodash');
+  var BaseObject = require('utils/BaseObject');
 
   /**
    * Simple event emitter class used in the vislib. Calls
@@ -7,6 +8,7 @@ define(function (require) {
    *
    * @class
    */
+  _(SimpleEmitter).inherits(BaseObject);
   function SimpleEmitter() {
     this._listeners = {};
   }
@@ -14,17 +16,15 @@ define(function (require) {
   /**
    * Add an event handler
    *
-   * @param  {string} event
+   * @param  {string} name
    * @param  {function} handler
    * @return {SimpleEmitter} - this, for chaining
    */
-  SimpleEmitter.prototype.on = function (event, handler) {
-    var handlers = this._listeners[event];
-    if (!handlers) handlers = this._listeners[event] = [];
+  SimpleEmitter.prototype.on = function (name, handler) {
+    var handlers = this._listeners[name];
+    if (!handlers) handlers = this._listeners[name] = [];
 
-    if (!_.contains(handlers, handler)) {
-      handlers.push(handler);
-    }
+    handlers.push(handler);
 
     return this;
   };
@@ -32,61 +32,24 @@ define(function (require) {
   /**
    * Remove an event handler
    *
-   * @param  {string} event
+   * @param  {string} name
    * @param  {function} [handler] - optional handler to remove, if no handler is
    *                              passed then all are removed
    * @return {SimpleEmitter} - this, for chaining
    */
-  SimpleEmitter.prototype.off = function (event, handler) {
-    if (!this._listeners[event]) {
+  SimpleEmitter.prototype.off = function (name, handler) {
+    if (!this._listeners[name]) {
       return this;
     }
 
     // remove a specific handler
-    if (handler) _.pull(this._listeners[event], handler);
+    if (handler) _.pull(this._listeners[name], handler);
     // or remove all listeners
-    else this._listeners[event] = null;
+    else this._listeners[name] = null;
 
     return this;
   };
 
-  /**
-   * Emit an event and all arguments to all listeners for an event name
-   *
-   * @param  {string} event
-   * @param  {*} [arg...] - any number of arguments that will be applied to each handler
-   * @return {SimpleEmitter} - this, for chaining
-   */
-  SimpleEmitter.prototype.emit = function (event, arg) {
-    if (!this._listeners[event]) return this;
-
-    var args = _.rest(arguments);
-    var handlers = this._listeners[event].slice(0);
-    var i = -1;
-
-    while (++i < handlers.length) {
-      handlers[i].apply(this, args);
-    }
-
-    return this;
-  };
-
-  /**
-   * Get the count of handlers for a specific event
-   *
-   * @param  {string} [event] - optional event name to filter by
-   * @return {number}
-   */
-  SimpleEmitter.prototype.listenerCount = function (event) {
-    if (event) {
-      return _.size(this._listeners[event]);
-    }
-
-    return _.reduce(this._listeners, function (count, handlers) {
-      return count + _.size(handlers);
-    }, 0);
-  };
-
   /**
    * Remove all event listeners bound to this emitter.
    *
@@ -97,5 +60,64 @@ define(function (require) {
     return this;
   };
 
+  /**
+   * Emit an event and all arguments to all listeners for an event name
+   *
+   * @param  {string} name
+   * @param  {*} [arg...] - any number of arguments that will be applied to each handler
+   * @return {SimpleEmitter} - this, for chaining
+   */
+  SimpleEmitter.prototype.emit = function (name, arg) {
+    if (!this._listeners[name]) return this;
+
+    var args = _.rest(arguments);
+    var listeners = this.listeners(name);
+    var i = -1;
+
+    while (++i < listeners.length) {
+      listeners[i].apply(this, args);
+    }
+
+    return this;
+  };
+
+  /**
+   * Get a list of the event names that currently have listeners
+   *
+   * @return {array[string]}
+   */
+  SimpleEmitter.prototype.activeEvents = function () {
+    return _.reduce(this._listeners, function (active, listeners, name) {
+      return active.concat(_.size(listeners) ? name : []);
+    }, []);
+  };
+
+  /**
+   * Get a list of the handler functions for a specific event
+   *
+   * @param  {string} name
+   * @return {array[function]}
+   */
+  SimpleEmitter.prototype.listeners = function (name) {
+    return this._listeners[name] ? this._listeners[name].slice(0) : [];
+  };
+
+  /**
+   * Get the count of handlers for a specific event
+   *
+   * @param  {string} [name] - optional event name to filter by
+   * @return {number}
+   */
+  SimpleEmitter.prototype.listenerCount = function (name) {
+    if (name) {
+      return _.size(this._listeners[name]);
+    }
+
+    return _.reduce(this._listeners, function (count, handlers) {
+      return count + _.size(handlers);
+    }, 0);
+  };
+
+
   return SimpleEmitter;
 });

test/unit/specs/utils/SimpleEmitter.js

@@ -55,12 +55,12 @@ define(function (require) {
         expect(emitter.listenerCount('a')).to.be(2);
       });
 
-      it('only registers a specific listener once', function () {
+      it('allows the same function to be registered multiple times', function () {
         var handler = function () {};
         emitter.on('a', handler);
         expect(emitter.listenerCount()).to.be(1);
         emitter.on('a', handler);
-        expect(emitter.listenerCount()).to.be(1);
+        expect(emitter.listenerCount()).to.be(2);
       });
     });