Move all support for the legacy API into a plugin (#4614)

* Make legacy support optional
* Fix order of legacy plugin registration
* Added 'supportComposition' function
* Add composition policy to check that parent supports composition
* Fix memory leaks in timer

index.html

@@ -75,6 +75,8 @@
         const TWO_HOURS = ONE_HOUR * 2;
         const ONE_DAY = ONE_HOUR * 24;
 
+        openmct.install(openmct.plugins.LegacySupport());
+
         [
             'example/eventGenerator'
         ].forEach(

src/MCT.js

@@ -22,24 +22,17 @@
 
 define([
     'EventEmitter',
-    './BundleRegistry',
-    './installDefaultBundles',
     './api/api',
     './api/overlays/OverlayAPI',
     './selection/Selection',
-    'objectUtils',
     './plugins/plugins',
-    './adapter/indicators/legacy-indicators-plugin',
     './ui/registries/ViewRegistry',
     './plugins/imagery/plugin',
     './ui/registries/InspectorViewRegistry',
     './ui/registries/ToolbarRegistry',
     './ui/router/ApplicationRouter',
     './ui/router/Browse',
-    '../platform/framework/src/Main',
     './ui/layout/Layout.vue',
-    '../platform/core/src/objects/DomainObjectImpl',
-    '../platform/core/src/capabilities/ContextualDomainObject',
     './ui/preview/plugin',
     './api/Branding',
     './plugins/licenses/plugin',
@@ -52,24 +45,17 @@ define([
     'vue'
 ], function (
     EventEmitter,
-    BundleRegistry,
-    installDefaultBundles,
     api,
     OverlayAPI,
     Selection,
-    objectUtils,
     plugins,
-    LegacyIndicatorsPlugin,
     ViewRegistry,
     ImageryPlugin,
     InspectorViewRegistry,
     ToolbarRegistry,
     ApplicationRouter,
     Browse,
-    Main,
     Layout,
-    DomainObjectImpl,
-    ContextualDomainObject,
     PreviewPlugin,
     BrandingAPI,
     LicensesPlugin,
@@ -106,23 +92,6 @@ define([
             revision: __OPENMCT_REVISION__,
             branch: __OPENMCT_BUILD_BRANCH__
         };
-        /* eslint-enable no-undef */
-
-        this.legacyBundle = {
-            extensions: {
-                services: [
-                    {
-                        key: "openmct",
-                        implementation: function ($injector) {
-                            this.$injector = $injector;
-
-                            return this;
-                        }.bind(this),
-                        depends: ['$injector']
-                    }
-                ]
-            }
-        };
 
         this.destroy = this.destroy.bind(this);
         /**
@@ -262,16 +231,12 @@ define([
 
         this.branding = BrandingAPI.default;
 
-        this.legacyRegistry = new BundleRegistry();
-        installDefaultBundles(this.legacyRegistry);
-
         // Plugins that are installed by default
 
         this.install(this.plugins.Plot());
         this.install(this.plugins.Chart());
         this.install(this.plugins.TelemetryTable.default());
         this.install(PreviewPlugin.default());
-        this.install(LegacyIndicatorsPlugin());
         this.install(LicensesPlugin.default());
         this.install(RemoveActionPlugin.default());
         this.install(MoveActionPlugin.default());
@@ -303,51 +268,6 @@ define([
 
     MCT.prototype.MCT = MCT;
 
-    MCT.prototype.legacyExtension = function (category, extension) {
-        this.legacyBundle.extensions[category] =
-            this.legacyBundle.extensions[category] || [];
-        this.legacyBundle.extensions[category].push(extension);
-    };
-
-    /**
-     * Return a legacy object, for compatibility purposes only.  This method
-     * will be deprecated and removed in the future.
-     * @private
-     */
-    MCT.prototype.legacyObject = function (domainObject) {
-        let capabilityService = this.$injector.get('capabilityService');
-
-        function instantiate(model, keyString) {
-            const capabilities = capabilityService.getCapabilities(model, keyString);
-            model.id = keyString;
-
-            return new DomainObjectImpl(keyString, model, capabilities);
-        }
-
-        if (Array.isArray(domainObject)) {
-            // an array of domain objects. [object, ...ancestors] representing
-            // a single object with a given chain of ancestors.  We instantiate
-            // as a single contextual domain object.
-            return domainObject
-                .map((o) => {
-                    let keyString = objectUtils.makeKeyString(o.identifier);
-                    let oldModel = objectUtils.toOldFormat(o);
-
-                    return instantiate(oldModel, keyString);
-                })
-                .reverse()
-                .reduce((parent, child) => {
-                    return new ContextualDomainObject(child, parent);
-                });
-
-        } else {
-            let keyString = objectUtils.makeKeyString(domainObject.identifier);
-            let oldModel = objectUtils.toOldFormat(domainObject);
-
-            return instantiate(oldModel, keyString);
-        }
-    };
-
     /**
      * Set path to where assets are hosted.  This should be the path to main.js.
      * @memberof module:openmct.MCT#
@@ -393,25 +313,6 @@ define([
 
         this.element = domElement;
 
-        this.legacyExtension('runs', {
-            depends: ['navigationService'],
-            implementation: function (navigationService) {
-                navigationService
-                    .addListener(this.emit.bind(this, 'navigation'));
-            }.bind(this)
-        });
-
-        // TODO: remove with legacy types.
-        this.types.listKeys().forEach(function (typeKey) {
-            const type = this.types.get(typeKey);
-            const legacyDefinition = type.toLegacyDefinition();
-            legacyDefinition.key = typeKey;
-            this.legacyExtension('types', legacyDefinition);
-        }.bind(this));
-
-        this.legacyRegistry.register('adapter', this.legacyBundle);
-        this.legacyRegistry.enable('adapter');
-
         this.router.route(/^\/$/, () => {
             this.router.setPath('/browse/');
         });
@@ -422,35 +323,27 @@ define([
          * @event start
          * @memberof module:openmct.MCT~
          */
-        const startPromise = new Main();
-        startPromise.run(this)
-            .then(function (angular) {
-                this.$angular = angular;
-                // OpenMCT Object provider doesn't operate properly unless
-                // something has depended upon objectService.  Cool, right?
-                this.$injector.get('objectService');
 
-                if (!isHeadlessMode) {
+        if (!isHeadlessMode) {
-                    const appLayout = new Vue({
+            const appLayout = new Vue({
-                        components: {
+                components: {
-                            'Layout': Layout.default
+                    'Layout': Layout.default
-                        },
+                },
-                        provide: {
+                provide: {
-                            openmct: this
+                    openmct: this
-                        },
+                },
-                        template: '<Layout ref="layout"></Layout>'
+                template: '<Layout ref="layout"></Layout>'
-                    });
+            });
-                    domElement.appendChild(appLayout.$mount().$el);
+            domElement.appendChild(appLayout.$mount().$el);
 
-                    this.layout = appLayout.$refs.layout;
+            this.layout = appLayout.$refs.layout;
-                    Browse(this);
+            Browse(this);
-                }
+        }
 
-                window.addEventListener('beforeunload', this.destroy);
+        window.addEventListener('beforeunload', this.destroy);
 
-                this.router.start();
+        this.router.start();
-                this.emit('start');
+        this.emit('start');
-            }.bind(this));
     };
 
     MCT.prototype.startHeadless = function () {

src/MCTSpec.js

@@ -22,21 +22,18 @@
 
 define([
     './plugins/plugins',
-    'legacyRegistry',
     'utils/testing'
-], function (plugins, legacyRegistry, testUtils) {
+], function (plugins, testUtils) {
     describe("MCT", function () {
         let openmct;
         let mockPlugin;
         let mockPlugin2;
         let mockListener;
-        let oldBundles;
 
         beforeEach(function () {
             mockPlugin = jasmine.createSpy('plugin');
             mockPlugin2 = jasmine.createSpy('plugin2');
             mockListener = jasmine.createSpy('listener');
-            oldBundles = legacyRegistry.list();
 
             openmct = testUtils.createOpenMct();
 
@@ -47,12 +44,6 @@ define([
 
         // Clean up the dirty singleton.
         afterEach(function () {
-            legacyRegistry.list().forEach(function (bundle) {
-                if (oldBundles.indexOf(bundle) === -1) {
-                    legacyRegistry.delete(bundle);
-                }
-            });
-
             return testUtils.resetApplicationState(openmct);
         });
 
@@ -111,10 +102,6 @@ define([
         describe("setAssetPath", function () {
             let testAssetPath;
 
-            beforeEach(function () {
-                openmct.legacyExtension = jasmine.createSpy('legacyExtension');
-            });
-
             it("configures the path for assets", function () {
                 testAssetPath = "some/path/";
                 openmct.setAssetPath(testAssetPath);

src/api/composition/CompositionAPI.js

@@ -133,5 +133,9 @@ define([
         });
     };
 
+    CompositionAPI.prototype.supportsComposition = function (domainObject) {
+        return this.get(domainObject) !== undefined;
+    };
+
     return CompositionAPI;
 });

src/api/composition/CompositionAPISpec.js

@@ -87,6 +87,12 @@ define([
                 expect(composition).toEqual(jasmine.any(CompositionCollection));
             });
 
+            it('correctly reflects composability', function () {
+                expect(compositionAPI.supportsComposition(domainObject)).toBe(true);
+                delete domainObject.composition;
+                expect(compositionAPI.supportsComposition(domainObject)).toBe(false);
+            });
+
             it('loads composition from domain object', function () {
                 const listener = jasmine.createSpy('addListener');
                 composition.on('add', listener);

src/api/composition/DefaultCompositionProvider.js

@@ -49,8 +49,10 @@ define([
         this.onMutation = this.onMutation.bind(this);
 
         this.cannotContainItself = this.cannotContainItself.bind(this);
+        this.supportsComposition = this.supportsComposition.bind(this);
 
         compositionAPI.addPolicy(this.cannotContainItself);
+        compositionAPI.addPolicy(this.supportsComposition);
     }
 
     /**
@@ -61,6 +63,13 @@ define([
             && parent.identifier.key === child.identifier.key);
     };
 
+    /**
+     * @private
+     */
+    DefaultCompositionProvider.prototype.supportsComposition = function (parent, child) {
+        return this.publicAPI.composition.supportsComposition(parent);
+    };
+
     /**
      * Check if this provider should be used to load composition for a
      * particular domain object.

src/plugins/LADTable/LADTableViewProvider.js

@@ -31,7 +31,7 @@ export default class LADTableViewProvider {
     }
 
     canView(domainObject) {
-        const supportsComposition = this.openmct.composition.get(domainObject) !== undefined;
+        const supportsComposition = this.openmct.composition.supportsComposition(domainObject);
         const providesTelemetry = this.openmct.telemetry.isTelemetryObject(domainObject);
 
         return domainObject.type === 'LadTable'

src/plugins/charts/pluginSpec.js

@@ -130,14 +130,6 @@ describe("the plugin", function () {
         let mockComposition;
 
         beforeEach(async () => {
-            const getFunc = openmct.$injector.get;
-            spyOn(openmct.$injector, "get")
-                .withArgs("exportImageService").and.returnValue({
-                    exportPNG: () => {},
-                    exportJPG: () => {}
-                })
-                .and.callFake(getFunc);
-
             barGraphObject = {
                 identifier: {
                     namespace: "",

src/plugins/clock/pluginSpec.js

@@ -87,6 +87,7 @@ describe("Clock plugin:", () => {
 
             spyOn(openmct.objects, 'get').and.returnValue(Promise.resolve(clockViewObject));
             spyOn(openmct.objects, 'save').and.returnValue(Promise.resolve(true));
+            spyOn(openmct.objects, 'supportsMutation').and.returnValue(true);
 
             const applicableViews = openmct.objectViews.get(clockViewObject, [clockViewObject]);
             clockViewProvider = applicableViews.find(viewProvider => viewProvider.key === 'clock.view');

src/plugins/condition/ConditionSetViewPolicy.js

@@ -1,34 +0,0 @@
-/*****************************************************************************
- * Open MCT, Copyright (c) 2014-2021, United States Government
- * as represented by the Administrator of the National Aeronautics and Space
- * Administration. All rights reserved.
- *
- * Open MCT is licensed 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.
- *
- * Open MCT includes source code licensed under additional open source
- * licenses. See the Open Source Licenses file (LICENSES.md) included with
- * this source code distribution or the Licensing information page available
- * at runtime from the About dialog for additional information.
- *****************************************************************************/
-
-function ConditionSetViewPolicy() {
-}
-
-ConditionSetViewPolicy.prototype.allow = function (view, domainObject) {
-    if (domainObject.getModel().type === 'conditionSet') {
-        return view.key === 'conditionSet.view';
-    }
-
-    return true;
-};
-
-export default ConditionSetViewPolicy;

src/plugins/condition/plugin.js

@@ -23,7 +23,6 @@ import ConditionSetViewProvider from './ConditionSetViewProvider.js';
 import ConditionSetCompositionPolicy from "./ConditionSetCompositionPolicy";
 import ConditionSetMetadataProvider from './ConditionSetMetadataProvider';
 import ConditionSetTelemetryProvider from './ConditionSetTelemetryProvider';
-import ConditionSetViewPolicy from './ConditionSetViewPolicy';
 import uuid from "uuid";
 
 export default function ConditionPlugin() {
@@ -55,10 +54,6 @@ export default function ConditionPlugin() {
                 domainObject.telemetry = {};
             }
         });
-        openmct.legacyExtension('policies', {
-            category: 'view',
-            implementation: ConditionSetViewPolicy
-        });
         openmct.composition.addPolicy(new ConditionSetCompositionPolicy(openmct).allow);
         openmct.telemetry.addProvider(new ConditionSetMetadataProvider(openmct));
         openmct.telemetry.addProvider(new ConditionSetTelemetryProvider(openmct));

src/plugins/legacySupport/installDefaultBundles.js

@@ -43,42 +43,42 @@ const DEFAULTS = [
 ];
 
 define([
-    '../src/adapter/bundle',
+    '../../adapter/bundle',
-    '../example/eventGenerator/bundle',
+    '../../../example/eventGenerator/bundle',
-    '../example/export/bundle',
+    '../../../example/export/bundle',
-    '../example/forms/bundle',
+    '../../../example/forms/bundle',
-    '../example/identity/bundle',
+    '../../../example/identity/bundle',
-    '../example/mobile/bundle',
+    '../../../example/mobile/bundle',
-    '../example/msl/bundle',
+    '../../../example/msl/bundle',
-    '../example/notifications/bundle',
+    '../../../example/notifications/bundle',
-    '../example/persistence/bundle',
+    '../../../example/persistence/bundle',
-    '../example/policy/bundle',
+    '../../../example/policy/bundle',
-    '../example/profiling/bundle',
+    '../../../example/profiling/bundle',
-    '../example/scratchpad/bundle',
+    '../../../example/scratchpad/bundle',
-    '../example/styleguide/bundle',
+    '../../../example/styleguide/bundle',
-    '../platform/commonUI/browse/bundle',
+    '../../../platform/commonUI/browse/bundle',
-    '../platform/commonUI/dialog/bundle',
+    '../../../platform/commonUI/dialog/bundle',
-    '../platform/commonUI/edit/bundle',
+    '../../../platform/commonUI/edit/bundle',
-    '../platform/commonUI/general/bundle',
+    '../../../platform/commonUI/general/bundle',
-    '../platform/commonUI/inspect/bundle',
+    '../../../platform/commonUI/inspect/bundle',
-    '../platform/commonUI/mobile/bundle',
+    '../../../platform/commonUI/mobile/bundle',
-    '../platform/commonUI/notification/bundle',
+    '../../../platform/commonUI/notification/bundle',
-    '../platform/commonUI/regions/bundle',
+    '../../../platform/commonUI/regions/bundle',
-    '../platform/containment/bundle',
+    '../../../platform/containment/bundle',
-    '../platform/core/bundle',
+    '../../../platform/core/bundle',
-    '../platform/entanglement/bundle',
+    '../../../platform/entanglement/bundle',
-    '../platform/exporters/bundle',
+    '../../../platform/exporters/bundle',
-    '../platform/features/static-markup/bundle',
+    '../../../platform/features/static-markup/bundle',
-    '../platform/framework/bundle',
+    '../../../platform/framework/bundle',
-    '../platform/framework/src/load/Bundle',
+    '../../../platform/framework/src/load/Bundle',
-    '../platform/identity/bundle',
+    '../../../platform/identity/bundle',
-    '../platform/persistence/aggregator/bundle',
+    '../../../platform/persistence/aggregator/bundle',
-    '../platform/persistence/elastic/bundle',
+    '../../../platform/persistence/elastic/bundle',
-    '../platform/persistence/queue/bundle',
+    '../../../platform/persistence/queue/bundle',
-    '../platform/policy/bundle',
+    '../../../platform/policy/bundle',
-    '../platform/representation/bundle',
+    '../../../platform/representation/bundle',
-    '../platform/status/bundle',
+    '../../../platform/status/bundle',
-    '../platform/telemetry/bundle'
+    '../../../platform/telemetry/bundle'
 ], function () {
     const LEGACY_BUNDLES = Array.from(arguments);
 

src/plugins/legacySupport/plugin.js

@@ -0,0 +1,126 @@
+/*****************************************************************************
+ * Open MCT, Copyright (c) 2014-2021, United States Government
+ * as represented by the Administrator of the National Aeronautics and Space
+ * Administration. All rights reserved.
+ *
+ * Open MCT is licensed 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.
+ *
+ * Open MCT includes source code licensed under additional open source
+ * licenses. See the Open Source Licenses file (LICENSES.md) included with
+ * this source code distribution or the Licensing information page available
+ * at runtime from the About dialog for additional information.
+ *****************************************************************************/
+import installDefaultBundles from './installDefaultBundles';
+import BundleRegistry from './BundleRegistry';
+import Main from '../../../platform/framework/src/Main';
+import objectUtils from '../../api/objects/object-utils';
+import DomainObjectImpl from '../../../platform/core/src/objects/DomainObjectImpl';
+import ContextualDomainObject from '../../../platform/core/src/capabilities/ContextualDomainObject';
+
+export default function LegacySupportPlugin() {
+    return function install(openmct) {
+        openmct.legacyBundle = {
+            extensions: {
+                services: [
+                    {
+                        key: "openmct",
+                        implementation: function ($injector) {
+                            openmct.$injector = $injector;
+
+                            return openmct;
+                        },
+                        depends: ['$injector']
+                    }
+                ]
+            }
+        };
+
+        openmct.legacyExtension = function (category, extension) {
+            this.legacyBundle.extensions[category] =
+                this.legacyBundle.extensions[category] || [];
+            this.legacyBundle.extensions[category].push(extension);
+        }.bind(openmct);
+
+        /**
+         * Return a legacy object, for compatibility purposes only.  This method
+         * will be deprecated and removed in the future.
+         * @private
+         */
+        openmct.legacyObject = function (domainObject) {
+            let capabilityService = this.$injector.get('capabilityService');
+
+            function instantiate(model, keyString) {
+                const capabilities = capabilityService.getCapabilities(model, keyString);
+                model.id = keyString;
+
+                return new DomainObjectImpl(keyString, model, capabilities);
+            }
+
+            if (Array.isArray(domainObject)) {
+                // an array of domain objects. [object, ...ancestors] representing
+                // a single object with a given chain of ancestors.  We instantiate
+                // as a single contextual domain object.
+                return domainObject
+                    .map((o) => {
+                        let keyString = objectUtils.makeKeyString(o.identifier);
+                        let oldModel = objectUtils.toOldFormat(o);
+
+                        return instantiate(oldModel, keyString);
+                    })
+                    .reverse()
+                    .reduce((parent, child) => {
+                        return new ContextualDomainObject(child, parent);
+                    });
+
+            } else {
+                let keyString = objectUtils.makeKeyString(domainObject.identifier);
+                let oldModel = objectUtils.toOldFormat(domainObject);
+
+                return instantiate(oldModel, keyString);
+            }
+        }.bind(openmct);
+
+        openmct.legacyRegistry = new BundleRegistry();
+        installDefaultBundles(openmct.legacyRegistry);
+
+        const patchedStart = openmct.start.bind(openmct);
+        openmct.start = async () => {
+            openmct.legacyRegistry.register('adapter', openmct.legacyBundle);
+            openmct.legacyRegistry.enable('adapter');
+
+            openmct.legacyExtension('runs', {
+                depends: ['navigationService'],
+                implementation: function (navigationService) {
+                    navigationService
+                        .addListener(openmct.emit.bind(openmct, 'navigation'));
+                }
+            });
+
+            // TODO: remove with legacy types.
+            openmct.types.listKeys().forEach(function (typeKey) {
+                const type = openmct.types.get(typeKey);
+                const legacyDefinition = type.toLegacyDefinition();
+                legacyDefinition.key = typeKey;
+                openmct.legacyExtension('types', legacyDefinition);
+            });
+
+            const main = new Main();
+            const angularInstance = await main.run(openmct);
+
+            openmct.$angular = angularInstance;
+            openmct.$injector.get('objectService');
+
+            return patchedStart();
+        };
+
+    };
+}

src/plugins/notificationIndicator/pluginSpec.js

@@ -30,7 +30,6 @@ import {
 describe('the plugin', () => {
     let notificationIndicatorPlugin;
     let openmct;
-    let indicatorObject;
     let indicatorElement;
     let parentElement;
     let mockMessages = ['error', 'test', 'notifications'];
@@ -43,9 +42,6 @@ describe('the plugin', () => {
 
         parentElement = document.createElement('div');
 
-        indicatorObject = openmct.indicators.indicatorObjects.find(indicator => indicator.key === 'notifications-indicator');
-        indicatorElement = indicatorObject.element;
-
         openmct.on('start', () => {
             mockMessages.forEach(message => {
                 openmct.notifications.error(message);
@@ -53,7 +49,7 @@ describe('the plugin', () => {
             done();
         });
 
-        openmct.startHeadless();
+        openmct.start();
     });
 
     afterEach(() => {
@@ -68,7 +64,7 @@ describe('the plugin', () => {
         });
 
         it('notifies the user of the number of notifications', () => {
-            let notificationCountElement = parentElement.querySelector('.c-indicator__count');
+            let notificationCountElement = document.querySelector('.c-indicator__count');
 
             expect(notificationCountElement.innerText).toEqual(mockMessages.length.toString());
         });

src/plugins/plot/pluginSpec.js

@@ -533,13 +533,6 @@ describe("the plugin", function () {
         let plotViewComponentObject;
 
         beforeEach(() => {
-            const getFunc = openmct.$injector.get;
-            spyOn(openmct.$injector, "get")
-                .withArgs("exportImageService").and.returnValue({
-                    exportPNG: () => {},
-                    exportJPG: () => {}
-                })
-                .and.callFake(getFunc);
 
             stackedPlotObject = {
                 identifier: {

src/plugins/plugins.js

@@ -74,7 +74,9 @@ define([
     './clock/plugin',
     './DeviceClassifier/plugin',
     './timer/plugin',
-    './localStorage/plugin'
+    './localStorage/plugin',
+    './legacySupport/plugin.js',
+    '../adapter/indicators/legacy-indicators-plugin'
 ], function (
     _,
     UTCTimeSystem,
@@ -129,7 +131,9 @@ define([
     Clock,
     DeviceClassifier,
     Timer,
-    LocalStorage
+    LocalStorage,
+    LegacySupportPlugin,
+    LegacyIndicatorsPlugin
 ) {
     const bundleMap = {
         Elasticsearch: 'platform/persistence/elastic'
@@ -237,6 +241,8 @@ define([
     plugins.Timer = Timer.default;
     plugins.DeviceClassifier = DeviceClassifier.default;
     plugins.LocalStorage = LocalStorage.default;
+    plugins.LegacySupport = LegacySupportPlugin.default;
+    plugins.LegacyIndicators = LegacyIndicatorsPlugin;
 
     return plugins;
 });

src/plugins/timer/components/Timer.vue

@@ -191,7 +191,7 @@ export default {
             });
         });
     },
-    destroyed() {
+    beforeDestroy() {
         this.active = false;
         if (this.unlisten) {
             this.unlisten();

src/plugins/timer/pluginSpec.js

@@ -60,6 +60,8 @@ describe("Timer plugin:", () => {
             timerDefinition = openmct.types.get('timer').definition;
             timerDefinition.initialize(timerDomainObject);
 
+            spyOn(openmct.objects, 'supportsMutation').and.returnValue(true);
+
             openmct.on('start', resolve);
             openmct.start(appHolder);
         });
@@ -93,6 +95,8 @@ describe("Timer plugin:", () => {
             const applicableViews = openmct.objectViews.get(timerViewObject, [timerViewObject]);
             timerViewProvider = applicableViews.find(viewProvider => viewProvider.key === 'timer.view');
 
+            spyOn(openmct.objects, 'get').and.returnValue(Promise.resolve(timerViewObject));
+
             mutableTimerObject = await openmct.objects.getMutable(timerViewObject.identifier);
 
             timerObjectPath = [mutableTimerObject];
@@ -102,6 +106,10 @@ describe("Timer plugin:", () => {
             await Vue.nextTick();
         });
 
+        afterEach(() => {
+            timerView.destroy();
+        });
+
         it("should migrate old object properties to the configuration section", () => {
             openmct.objects.applyGetInterceptors(timerViewObject.identifier, timerViewObject);
             expect(timerViewObject.configuration.timerFormat).toBe('short');

src/utils/clock/Ticker.js

@@ -24,8 +24,6 @@ class Ticker {
     constructor() {
         this.callbacks = [];
         this.last = new Date() - 1000;
-
-        this.tick();
     }
 
     /**
@@ -47,7 +45,7 @@ class Ticker {
         }
 
         // Try to update at exactly the next second
-        setTimeout(() => {
+        this.timeoutHandle = setTimeout(() => {
             this.tick();
         }, 1000 - millis, true);
     }
@@ -62,6 +60,10 @@ class Ticker {
      * @returns {Function} a function to unregister this listener
      */
     listen(callback) {
+        if (this.callbacks.length === 0) {
+            this.tick();
+        }
+
         this.callbacks.push(callback);
 
         // Provide immediate feedback
@@ -72,6 +74,10 @@ class Ticker {
             this.callbacks = this.callbacks.filter(function (cb) {
                 return cb !== callback;
             });
+
+            if (this.callbacks.length === 0) {
+                clearTimeout(this.timeoutHandle);
+            }
         };
     }
 }