Add test for altField focus redirection

Author: emlun

test/.jshintrc

@@ -15,6 +15,7 @@
 		"jQuery",
 		"$",
 		"QUnit",
+		"jasmine",
 		"module",
 		"test",
 		"asyncTest",

test/jquery-ui-timepicker-addon_spec.js

@@ -661,4 +661,28 @@ describe('datetimepicker', function() {
 			});
 		});
 	});
+
+	describe('altField', function() {
+		var $input;
+		var $altField;
+		var inputFocusSpy;
+
+		beforeEach(function() {
+			$input = affix('input');
+			$altField = affix('input');
+
+			inputFocusSpy = jasmine.createSpy();
+			$input.focus(inputFocusSpy);
+		});
+
+		it('should redirect focus to main field', function() {
+			$input.datetimepicker({
+				showOn: 'button',
+				altField: $altField,
+			});
+
+			$altField.trigger('focus');
+			expect(inputFocusSpy).toHaveBeenCalled();
+		});
+	});
 });