GUACAMOLE-1204: Add generic, listener-driven event system.

guacamole-common-js/src/test/javascript/EventSpec.js

@@ -0,0 +1,139 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/* global Guacamole, jasmine, expect */
+
+describe("Guacamole.Event", function EventSpec() {
+
+    /**
+     * Test subclass of {@link Guacamole.Event} which provides a single
+     * "value" property supports an "ontest" legacy event handler.
+     *
+     * @constructor
+     * @augments Guacamole.Event
+     */
+    var TestEvent = function TestEvent(value) {
+
+        Guacamole.Event.apply(this, [ 'test' ]);
+
+        /**
+         * An arbitrary value to expose to the handler of this event.
+         *
+         * @type {Object}
+         */
+        this.value = value;
+
+        /**
+         * @inheritdoc
+         */
+        this.invokeLegacyHandler = function invokeLegacyHandler(target) {
+            if (target.ontest)
+                target.ontest(value);
+        };
+
+    };
+
+    /**
+     * Event target instance which will receive each fired {@link TestEvent}.
+     *
+     * @type {Guacamole.Event.Target}
+     */
+    var eventTarget;
+
+    beforeEach(function() {
+        eventTarget = new Guacamole.Event.Target();
+    });
+
+    describe("when an event is dispatched", function(){
+
+        it("should invoke the legacy handler for matching events", function() {
+
+            eventTarget.ontest = jasmine.createSpy('ontest');
+            eventTarget.dispatch(new TestEvent('event1'));
+            expect(eventTarget.ontest).toHaveBeenCalledWith('event1');
+
+        });
+
+        it("should invoke all listeners for matching events", function() {
+
+            var listener1 = jasmine.createSpy('listener1');
+            var listener2 = jasmine.createSpy('listener2');
+
+            eventTarget.on('test', listener1);
+            eventTarget.on('test', listener2);
+
+            eventTarget.dispatch(new TestEvent('event2'));
+
+            expect(listener1).toHaveBeenCalledWith(jasmine.objectContaining({ type : 'test', value : 'event2' }), eventTarget);
+            expect(listener2).toHaveBeenCalledWith(jasmine.objectContaining({ type : 'test', value : 'event2' }), eventTarget);
+
+        });
+
+        it("should not invoke any listeners for non-matching events", function() {
+
+            var listener1 = jasmine.createSpy('listener1');
+            var listener2 = jasmine.createSpy('listener2');
+
+            eventTarget.on('test2', listener1);
+            eventTarget.on('test2', listener2);
+
+            eventTarget.dispatch(new TestEvent('event3'));
+
+            expect(listener1).not.toHaveBeenCalled();
+            expect(listener2).not.toHaveBeenCalled();
+
+        });
+
+        it("should not invoke any listeners that have been removed", function() {
+
+            var listener1 = jasmine.createSpy('listener1');
+            var listener2 = jasmine.createSpy('listener2');
+
+            eventTarget.on('test', listener1);
+            eventTarget.on('test', listener2);
+            eventTarget.off('test', listener1);
+
+            eventTarget.dispatch(new TestEvent('event4'));
+
+            expect(listener1).not.toHaveBeenCalled();
+            expect(listener2).toHaveBeenCalledWith(jasmine.objectContaining({ type : 'test', value : 'event4' }), eventTarget);
+
+        });
+
+    });
+
+    describe("when listeners are removed", function(){
+
+        it("should return whether a listener is successfully removed", function() {
+
+            var listener1 = jasmine.createSpy('listener1');
+            var listener2 = jasmine.createSpy('listener2');
+
+            eventTarget.on('test', listener1);
+            eventTarget.on('test', listener2);
+
+            expect(eventTarget.off('test', listener1)).toBe(true);
+            expect(eventTarget.off('test', listener1)).toBe(false);
+            expect(eventTarget.off('test', listener2)).toBe(true);
+            expect(eventTarget.off('test', listener2)).toBe(false);
+
+        });
+
+    });
+});