cherry-pick(#7057): Memory leak fixes for several views (#7070)

* Change the mount utility to use Vue's createApp and defineComponent methods

* Fix display layout memory leaks caused by `getSelectionContext`

* fix some display layout leaks due to use of slots

* Fix imagery memory leak (removed span tag). NOTE: CompassRose svg leaks memory - must test on firefox to see if this is a Chrome leak.

* Fix ActionsAPI action collection and applicable actions leak.

* Fix flexible layout memory leaks - remove listeners on unmount. NOTE: One type of overlay plot (Rover Yaw) is still leaking.

* pass in the el on mount

* e2e test config and spec changes

* Remove mounting of limit lines. Use components directly

* test: remove `.only()`

* Fix display layout memory leaks

* Enable passing tests

* e2e README and appActions should be what master has.

* lint: add word to cspell list

* lint: fixes

* lint:fix

* fix: revert `el` change

* fix: remove empty span

* fix: creating shapes in displayLayout

* fix: avoid `splice` as it loses reactivity

* test: reduce timeout time

* quick fixes

* add prod mode and convert the test config to select the correct mode

* Fix webpack prod config

* Add launch flag for exposing window.gc

* never worked

* explicit naming

* rename

* We don't need to destroy view providers

* test: increase timeout time

* test: unskip all mem tests

* fix(vue-loader): disable static hoisting

* chore: run `test:perf:memory`

* Don't destroy view providers

* Move context menu once listener to beforeUnmount instead.

* Disconnect all resize observers on unmount

* Delete Test vue component

* Use beforeUnmount and remove splice(0) in favor of [] for emptying arrays

* re-structure

* fix: unregister listener in pane.vue

* test: tweak timeouts

* chore: lint:fix

* test: unskip perf tests

* fix: unregister events properly

* fix: unregister listener

* fix: unregister listener

* fix: unregister listener

* fix: use `unmounted()`

* fix: unregister listeners

* fix: unregister listener properly

* chore: lint:fix

* test: fix imagery layer toggle test

* test: increase timeout

* Don't use anonymous functions for listeners

* Destroy objects and event listeners properly

* Delete config stores that are created by components

* Use the right unmount hook. Destroy mounted view on unmount.

* Use unmounted, not beforeUnmounted

* Lint fixes

* Fix time strip memory leak

* Undo unneeded change for memory leaks.

* chore: combine common webpack configs

---------

Co-authored-by: Shefali Joshi <simplyrender@gmail.com>
Co-authored-by: John Hill <john.c.hill@nasa.gov>

.circleci/config.yml

@@ -197,7 +197,9 @@ jobs:
     steps:
       - build_and_install:
           node-version: <<parameters.node-version>>
-      - run: npm run test:perf
+      - run: npm run test:perf:memory
+      - run: npm run test:perf:localhost
+      - run: npm run test:perf:contract
       - store_test_results:
           path: test-results/results.xml
       - store_artifacts:

.cspell.json

@@ -480,7 +480,10 @@
     "sinonjs",
     "generatedata",
     "grandsearch",
-    "websockets"
+    "websockets",
+    "swgs",
+    "memlab",
+    "devmode"
   ],
   "dictionaries": ["npm", "softwareTerms", "node", "html", "css", "bash", "en_US"],
   "ignorePaths": [

.webpack/webpack.common.js

@@ -33,6 +33,16 @@ const projectRootDir = path.resolve(__dirname, '..');
 /** @type {import('webpack').Configuration} */
 const config = {
   context: projectRootDir,
+  devServer: {
+    client: {
+      progress: true,
+      overlay: {
+        // Disable overlay for runtime errors.
+        // See: https://github.com/webpack/webpack-dev-server/issues/4771
+        runtimeErrors: false
+      }
+    }
+  },
   entry: {
     openmct: './openmct.js',
     generatorWorker: './example/generator/generatorWorker.js',
@@ -125,6 +135,7 @@ const config = {
         loader: 'vue-loader',
         options: {
           compilerOptions: {
+            hoistStatic: false,
             whitespace: 'preserve',
             compatConfig: {
               MODE: 2

.webpack/webpack.dev.js

@@ -45,14 +45,6 @@ module.exports = merge(common, {
       directory: path.join(__dirname, '..', '/dist'),
       publicPath: '/dist',
       watch: false
-    },
-    client: {
-      progress: true,
-      overlay: {
-        // Disable overlay for runtime errors.
-        // See: https://github.com/webpack/webpack-dev-server/issues/4771
-        runtimeErrors: false
-      }
     }
   }
 });

e2e/README.md

@@ -134,11 +134,11 @@ npm run test:e2e:updatesnapshots
 
 ## Performance Testing
 
-The open source performance tests function mostly as a contract for the locator logic, functionality, and assumptions will work in our downstream, closed source test suites.
+The open source performance tests function in three ways which match their naming and folder structure:
 
-They're found under `./e2e/tests/performance` and are to be executed with the following npm script:
+`./e2e/tests/performance` - The tests at the root of this folder path detect functional changes which are mostly apparent with large performance regressions like [this](https://github.com/nasa/openmct/issues/6879). These tests run against openmct webpack in `production-mode` with the `npm run test:perf:localhost` script.
-
+`./e2e/tests/performance/contract/` -  These tests serve as [contracts](https://martinfowler.com/bliki/ContractTest.html) for the locator logic, functionality, and assumptions will work in our downstream, closed source test suites. These tests run against openmct webpack in `dev-mode` with the `npm run test:perf:contract` script.
-`npm run test:perf`
+`./e2e/tests/performance/memory/` -  These tests execute memory leak detection checks in various ways. This is expected to evolve as we move to the `memlab` project. These tests run against openmct webpack in `production-mode` with the `npm run test:perf:memory` script.
 
 These tests are expected to become blocking and gating with assertions as we extend the capabilities of Playwright.
 
@@ -158,8 +158,11 @@ Our file structure follows the type of type of testing being excercised at the e
 |`./tests/functional/example/` | Tests which specifically verify the example plugins (e.g.: Sine Wave Generator).|
 |`./tests/functional/plugins/` | Tests which loosely test each plugin. This folder is the most likely to change. Note: some `@snapshot` tests are still contained within this structure.|
 |`./tests/framework/`          | Tests which verify that our testing framework's functionality and assumptions will continue to work based on further refactoring or Playwright version changes (e.g.: verifying custom fixtures and appActions).|
-|`./tests/performance/`        | Performance tests.|
+|`./tests/performance/`        | Performance tests which should be run on every commit.|
+|`./tests/performance/contract/` | A subset of performance tests which are designed to provide a contract between the open source tests which are run on every commit and the downstream tests which are run post merge and with other frameworks.|
+|`./tests/performance/memory`  | A subset of performance tests which are designed to test for memory leaks.|
 |`./tests/visual/`             | Visual tests.|
+|`./tests/visual/component/`             | Visual tests which are only run against a single component.|
 |`./appActions.js`             | Contains common methods which can be leveraged by test case authors to quickly move through the application when writing new tests.|
 |`./baseFixture.js`            | Contains base fixtures which only extend default `@playwright/test` functionality. The expectation is that these fixtures will be removed as the native Playwright API improves|
 
@@ -176,6 +179,7 @@ Open MCT is leveraging the [config file](https://playwright.dev/docs/test-config
 |`./playwright-ci.config.js` | Used when running in CI or to debug CI issues locally|
 |`./playwright-local.config.js` | Used when running locally|
 |`./playwright-performance.config.js` | Used when running performance tests in CI or locally|
+|`./playwright-performance-devmode.config.js` | Used when running performance tests in CI or locally|
 |`./playwright-visual.config.js` | Used to run the visual tests in CI or locally|
 
 #### Test Tags

e2e/playwright-performance-dev.config.js

@@ -2,25 +2,24 @@
 // playwright.config.js
 // @ts-check
 
-const CI = process.env.CI === 'true';
-
 /** @type {import('@playwright/test').PlaywrightTestConfig} */
 const config = {
   retries: 1, //Only for debugging purposes for trace: 'on-first-retry'
   testDir: 'tests/performance/',
+  testMatch: '*.contract.perf.spec.js', //Run everything except contract tests which require marks in dev mode
   timeout: 60 * 1000,
   workers: 1, //Only run in serial with 1 worker
   webServer: {
-    command: 'npm run start', //coverage not generated
+    command: 'npm run start', //need development mode for performance.marks and others
     url: 'http://localhost:8080/#',
     timeout: 200 * 1000,
-    reuseExistingServer: !CI
+    reuseExistingServer: false
   },
   use: {
     browserName: 'chromium',
     baseURL: 'http://localhost:8080/',
-    headless: CI, //Only if running locally
+    headless: true,
-    ignoreHTTPSErrors: true,
+    ignoreHTTPSErrors: false, //HTTP performance varies!
     screenshot: 'off',
     trace: 'on-first-retry',
     video: 'off'
@@ -28,6 +27,7 @@ const config = {
   projects: [
     {
       name: 'chrome',
+      testIgnore: '*.memory.perf.spec.js', //Do not run memory tests without proper flags. Shouldn't get here
       use: {
         browserName: 'chromium'
       }

e2e/playwright-performance-prod.config.js

@@ -0,0 +1,60 @@
+/* eslint-disable no-undef */
+// playwright.config.js
+// @ts-check
+
+/** @type {import('@playwright/test').PlaywrightTestConfig} */
+const config = {
+  retries: 0, //Only for debugging purposes for trace: 'on-first-retry'
+  testDir: 'tests/performance/',
+  testIgnore: '*.contract.perf.spec.js', //Run everything except contract tests which require marks in dev mode
+  timeout: 60 * 1000,
+  workers: 1, //Only run in serial with 1 worker
+  webServer: {
+    command: 'npm run start:prod', //Production mode
+    url: 'http://localhost:8080/#',
+    timeout: 200 * 1000,
+    reuseExistingServer: false //Must be run with this option to prevent dev mode
+  },
+  use: {
+    baseURL: 'http://localhost:8080/',
+    headless: true,
+    ignoreHTTPSErrors: false, //HTTP performance varies!
+    screenshot: 'off',
+    trace: 'on-first-retry',
+    video: 'off'
+  },
+  projects: [
+    {
+      name: 'chrome-memory',
+      testMatch: '*.memory.perf.spec.js', //Only run memory tests
+      use: {
+        browserName: 'chromium',
+        launchOptions: {
+          args: [
+            '--no-sandbox',
+            '--disable-notifications',
+            '--use-fake-ui-for-media-stream',
+            '--use-fake-device-for-media-stream',
+            '--js-flags=--no-move-object-start --expose-gc',
+            '--enable-precise-memory-info',
+            '--display=:100'
+          ]
+        }
+      }
+    },
+    {
+      name: 'chrome',
+      testIgnore: '*.memory.perf.spec.js', //Do not run memory tests without proper flags
+      use: {
+        browserName: 'chromium'
+      }
+    }
+  ],
+  reporter: [
+    ['list'],
+    ['junit', { outputFile: '../test-results/results.xml' }],
+    ['json', { outputFile: '../test-results/results.json' }]
+  ]
+};
+
+module.exports = config;

e2e/tests/performance/memleak-imagery.perf.spec.js

@@ -1,121 +0,0 @@
-/*****************************************************************************
- * Open MCT, Copyright (c) 2014-2023, 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.
- *****************************************************************************/
-
-/*
-This test suite is an initial example for memory leak testing using performance. This configuration and execution must
-be kept separate from the traditional performance measurements to avoid any "observer" effects associated with tracing
-or profiling playwright and/or the browser.
-
-Based on a pattern identified in https://github.com/trentmwillis/devtools-protocol-demos/blob/master/testing-demos/memory-leak-by-heap.js
-and https://github.com/paulirish/automated-chrome-profiling/issues/3
-
-Best path forward: https://github.com/cowchimp/headless-devtools/blob/master/src/Memory/example.js
-
-*/
-
-const { test, expect } = require('@playwright/test');
-
-const filePath = 'e2e/test-data/PerformanceDisplayLayout.json';
-
-// eslint-disable-next-line playwright/no-skipped-test
-test.describe.skip('Memory Performance tests', () => {
-  test.beforeEach(async ({ page, browser }, testInfo) => {
-    // Go to baseURL
-    await page.goto('./', { waitUntil: 'networkidle' });
-
-    // Click a:has-text("My Items")
-    await page.locator('a:has-text("My Items")').click({
-      button: 'right'
-    });
-
-    // Click text=Import from JSON
-    await page.locator('text=Import from JSON').click();
-
-    // Upload Performance Display Layout.json
-    await page.setInputFiles('#fileElem', filePath);
-
-    // Click text=OK
-    await page.locator('text=OK').click();
-
-    await expect(
-      page.locator('a:has-text("Performance Display Layout Display Layout")')
-    ).toBeVisible();
-  });
-
-  test('Embedded View Large for Imagery is performant in Fixed Time', async ({ page, browser }) => {
-    await page.goto('./', { waitUntil: 'networkidle' });
-
-    // To to Search Available after Launch
-    await page.locator('[aria-label="OpenMCT Search"] input[type="search"]').click();
-    // Fill Search input
-    await page
-      .locator('[aria-label="OpenMCT Search"] input[type="search"]')
-      .fill('Performance Display Layout');
-    //Search Result Appears and is clicked
-    await Promise.all([
-      page.waitForNavigation(),
-      page.locator('a:has-text("Performance Display Layout")').first().click()
-    ]);
-
-    //Time to Example Imagery Frame loads within Display Layout
-    await page.waitForSelector('.c-imagery__main-image__bg', { state: 'visible' });
-    //Time to Example Imagery object loads
-    await page.waitForSelector('.c-imagery__main-image__background-image', { state: 'visible' });
-
-    const client = await page.context().newCDPSession(page);
-    await client.send('HeapProfiler.enable');
-    await client.send('HeapProfiler.startSampling');
-    // await client.send('HeapProfiler.collectGarbage');
-    await client.send('Performance.enable');
-
-    let performanceMetricsBefore = await client.send('Performance.getMetrics');
-    console.log(performanceMetricsBefore.metrics);
-
-    //await client.send('Performance.disable');
-
-    //Open Large view
-    await page.locator('button:has-text("Large View")').click();
-    await client.send('HeapProfiler.takeHeapSnapshot');
-
-    //Time to Imagery Rendered in Large Frame
-    await page.waitForSelector('.c-imagery__main-image__bg', { state: 'visible' });
-
-    //Time to Example Imagery object loads
-    await page.waitForSelector('.c-imagery__main-image__background-image', { state: 'visible' });
-
-    // Click Close Icon
-    await page.locator('.c-click-icon').click();
-
-    //Time to Example Imagery Frame loads within Display Layout
-    await page.waitForSelector('.c-imagery__main-image__bg', { state: 'visible' });
-    //Time to Example Imagery object loads
-    await page.waitForSelector('.c-imagery__main-image__background-image', { state: 'visible' });
-
-    await client.send('HeapProfiler.collectGarbage');
-    //await client.send('Performance.enable');
-
-    let performanceMetricsAfter = await client.send('Performance.getMetrics');
-    console.log(performanceMetricsAfter.metrics);
-
-    //await client.send('Performance.disable');
-  });
-});

e2e/tests/performance/memory/navigation.memory.perf.spec.js

@@ -0,0 +1,299 @@
+/*****************************************************************************
+ * Open MCT, Copyright (c) 2014-2023, 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.
+ *****************************************************************************/
+
+const { test, expect } = require('@playwright/test');
+
+const memoryLeakFilePath = 'e2e/test-data/memory-leak-detection.json';
+/**
+ * Executes tests to verify that views are not leaking memory on navigation away. This sort of
+ * memory leak is generally caused by a failure to clean up registered listeners.
+ *
+ * These tests are executed on a set of pre-built displays loaded from ../test-data/memory-leak-detection.json.
+ *
+ * In order to modify the test data set:
+ * 1. Run Open MCT locally (npm start)
+ * 2. Right click on a folder in the tree, and select "Import From JSON"
+ * 3. In the subsequent dialog, select the file ../test-data/memory-leak-detection.json
+ * 4. Click "OK"
+ * 5. Modify test objects as desired
+ * 6. Right click on the "Memory Leak Detection" folder, and select "Export to JSON"
+ * 7. Copy the exported file to ../test-data/memory-leak-detection.json
+ *
+ */
+
+const NAV_LEAK_TIMEOUT = 10 * 1000; // 10s
+test.describe('Navigation memory leak is not detected in', () => {
+  test.beforeEach(async ({ page }) => {
+    // Go to baseURL
+    await page.goto('./', { waitUntil: 'domcontentloaded' });
+
+    await page.locator('a:has-text("My Items")').click({
+      button: 'right'
+    });
+
+    await page.locator('text=Import from JSON').click();
+
+    // Upload memory-leak-detection.json
+    await page.setInputFiles('#fileElem', memoryLeakFilePath);
+
+    await page.locator('text=OK').click();
+
+    await expect(page.locator('a:has-text("Memory Leak Detection")')).toBeVisible();
+  });
+
+  test('plot view', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(page, 'overlay-plot-single-1hz-swg', {
+      timeout: NAV_LEAK_TIMEOUT
+    });
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  test('stacked plot view', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(page, 'stacked-plot-single-1hz-swg', {
+      timeout: NAV_LEAK_TIMEOUT
+    });
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  test('LAD table view', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(page, 'lad-table-single-1hz-swg', {
+      timeout: NAV_LEAK_TIMEOUT
+    });
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  test('LAD table set', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(page, 'lad-table-set-single-1hz-swg', {
+      timeout: NAV_LEAK_TIMEOUT
+    });
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  //TODO: Figure out why using the `table-row` component inside the `table` component leaks TelemetryTableRow objects
+  test('telemetry table view', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(
+      page,
+      'telemetry-table-single-1hz-swg',
+      {
+        timeout: NAV_LEAK_TIMEOUT
+      }
+    );
+
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  //TODO: Figure out why using the `SideBar` component inside the leaks Notebook objects
+  test('notebook view', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(
+      page,
+      'notebook-memory-leak-detection-test',
+      {
+        timeout: NAV_LEAK_TIMEOUT
+      }
+    );
+
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  test('display layout of a single SWG alphanumeric', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(
+      page,
+      'display-layout-single-1hz-swg',
+      {
+        timeout: NAV_LEAK_TIMEOUT
+      }
+    );
+
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  test('display layout of a single SWG plot', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(
+      page,
+      'display-layout-single-overlay-plot',
+      {
+        timeout: NAV_LEAK_TIMEOUT
+      }
+    );
+
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  //TODO: Figure out why `svg` in the CompassRose component leaks imagery
+  test('example imagery view', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(
+      page,
+      'example-imagery-memory-leak-test',
+      {
+        timeout: NAV_LEAK_TIMEOUT * 6 // 1 min
+      }
+    );
+
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  test('display layout of example imagery views', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(
+      page,
+      'display-layout-images-memory-leak-test',
+      {
+        timeout: NAV_LEAK_TIMEOUT * 6 // 1 min
+      }
+    );
+
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  test('display layout with plots of swgs, alphanumerics, and condition sets, ', async ({
+    page
+  }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(
+      page,
+      'display-layout-simple-telemetry',
+      {
+        timeout: NAV_LEAK_TIMEOUT * 6 // 1 min
+      }
+    );
+
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  test('flexible layout with plots of swgs', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(
+      page,
+      'flexible-layout-plots-memory-leak-test',
+      {
+        timeout: NAV_LEAK_TIMEOUT
+      }
+    );
+
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  test('flexible layout of example imagery views', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(
+      page,
+      'flexible-layout-images-memory-leak-test',
+      {
+        timeout: NAV_LEAK_TIMEOUT * 6 // 1 min
+      }
+    );
+
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  test('tabbed view of display layouts and time strips', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(
+      page,
+      'tab-view-simple-memory-leak-test',
+      {
+        timeout: NAV_LEAK_TIMEOUT * 6 * 2 // 2 min
+      }
+    );
+
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  test('time strip view of telemetry', async ({ page }) => {
+    const result = await navigateToObjectAndDetectMemoryLeak(
+      page,
+      'time-strip-telemetry-memory-leak-test',
+      {
+        timeout: NAV_LEAK_TIMEOUT * 6 // 1 min
+      }
+    );
+
+    // If we got here without timing out, then the root view object was garbage collected and no memory leak was detected.
+    expect(result).toBe(true);
+  });
+
+  /**
+   *
+   * @param {import('@playwright/test').Page} page
+   * @param {*} objectName
+   * @returns
+   */
+  async function navigateToObjectAndDetectMemoryLeak(page, objectName) {
+    await page.locator('[aria-label="OpenMCT Search"] input[type="search"]').click();
+    // Fill Search input
+    await page.locator('[aria-label="OpenMCT Search"] input[type="search"]').fill(objectName);
+
+    //Search Result Appears and is clicked
+    await Promise.all([
+      page.locator(`div.c-gsearch-result__title:has-text("${objectName}")`).first().click(),
+      page.waitForNavigation()
+    ]);
+
+    // Register a finalization listener on the root node for the view. This tends to be the last thing to be
+    // garbage collected since it has either direct or indirect references to all resources used by the view. Therefore it's a pretty good proxy
+    // for detecting memory leaks.
+    await page.evaluate(() => {
+      window.gcPromise = new Promise((resolve) => {
+        // eslint-disable-next-line no-undef
+        window.fr = new FinalizationRegistry(resolve);
+        window.fr.register(
+          window.openmct.layout.$refs.browseObject.$refs.objectViewWrapper.firstChild,
+          'navigatedObject',
+          window.openmct.layout.$refs.browseObject.$refs.objectViewWrapper.firstChild
+        );
+      });
+    });
+
+    // Nav back to folder
+    await page.goto('./#/browse/mine', { waitUntil: 'networkidle' });
+    await page.waitForNavigation();
+
+    // This next code block blocks until the finalization listener is called and the gcPromise resolved. This means that the root node for the view has been garbage collected.
+    // In the event that the root node is not garbage collected, the gcPromise will never resolve and the test will time out.
+    await page.evaluate(() => {
+      const gcPromise = window.gcPromise;
+      window.gcPromise = null;
+
+      // Manually invoke the garbage collector once all references are removed.
+      window.gc();
+
+      return gcPromise;
+    });
+
+    // Clean up the finalization registry since we don't need it any more.
+    await page.evaluate(() => {
+      window.fr = null;
+    });
+
+    // If we get here without timing out, it means the garbage collection promise resolved and the test passed.
+    return true;
+  }
+});

package.json

@@ -79,6 +79,7 @@
     "clean": "rm -rf ./dist ./node_modules ./package-lock.json ./coverage ./html-test-results ./test-results ./.nyc_output ",
     "clean-test-lint": "npm run clean; npm install; npm run test; npm run lint",
     "start": "npx webpack serve --config ./.webpack/webpack.dev.js",
+    "start:prod": "npx webpack serve --config ./.webpack/webpack.prod.js",
     "start:coverage": "npx webpack serve --config ./.webpack/webpack.coverage.js",
     "lint": "eslint example src e2e --ext .js openmct.js --max-warnings=0 && eslint example src --ext .vue",
     "lint:spelling": "cspell \"**/*.{js,md,vue}\" --show-context --gitignore",
@@ -101,7 +102,9 @@
     "test:e2e:visual:full": "percy exec --config ./e2e/.percy.nightly.yml -- npx playwright test --config=e2e/playwright-visual.config.js --grep-invert @unstable",
     "test:e2e:full": "npx playwright test --config=e2e/playwright-ci.config.js --grep-invert @couchdb",
     "test:e2e:watch": "npx playwright test --ui --config=e2e/playwright-ci.config.js",
-    "test:perf": "npx playwright test --config=e2e/playwright-performance.config.js",
+    "test:perf:contract": "npx playwright test --config=e2e/playwright-performance-dev.config.js",
+    "test:perf:localhost": "npx playwright test --config=e2e/playwright-performance-prod.config.js --project=chrome",
+    "test:perf:memory": "npx playwright test --config=e2e/playwright-performance-prod.config.js --project=chrome-memory",
     "update-about-dialog-copyright": "perl -pi -e 's/20\\d\\d\\-202\\d/2014\\-2023/gm' ./src/ui/layout/AboutDialog.vue",
     "update-copyright-date": "npm run update-about-dialog-copyright && grep -lr --null --include=*.{js,scss,vue,ts,sh,html,md,frag} 'Copyright (c) 20' . | xargs -r0 perl -pi -e 's/Copyright\\s\\(c\\)\\s20\\d\\d\\-20\\d\\d/Copyright \\(c\\)\\ 2014\\-2023/gm'",
     "cov:e2e:report": "nyc report --reporter=lcovonly --report-dir=./coverage/e2e",

src/api/actions/ActionsAPI.js

@@ -92,7 +92,7 @@ class ActionsAPI extends EventEmitter {
     if (this._actionCollections.has(key)) {
       let actionCollection = this._actionCollections.get(key);
       actionCollection.off('destroy', this._updateCachedActionCollections);
-
+      delete actionCollection.applicableActions;
       this._actionCollections.delete(key);
     }
   }

src/api/composition/CompositionProvider.js

@@ -185,9 +185,10 @@ export default class CompositionProvider {
       return;
     }
 
-    this.#publicAPI.objects.eventEmitter.on('mutation', this.#onMutation.bind(this));
+    const onMutation = this.#onMutation.bind(this);
+    this.#publicAPI.objects.eventEmitter.on('mutation', onMutation);
     this.topicListener = () => {
-      this.#publicAPI.objects.eventEmitter.off('mutation', this.#onMutation.bind(this));
+      this.#publicAPI.objects.eventEmitter.off('mutation', onMutation);
     };
   }
 

src/plugins/charts/bar/BarGraphPlot.vue

@@ -98,7 +98,7 @@ export default {
   },
   beforeUnmount() {
     if (this.plotResizeObserver) {
-      this.plotResizeObserver.unobserve(this.$refs.plotWrapper);
+      this.plotResizeObserver.disconnect();
       clearTimeout(this.resizeTimer);
     }
 

src/plugins/charts/scatter/ScatterPlotWithUnderlay.vue

@@ -115,7 +115,7 @@ export default {
     }
 
     if (this.plotResizeObserver) {
-      this.plotResizeObserver.unobserve(this.$refs.plotWrapper);
+      this.plotResizeObserver.disconnect();
       clearTimeout(this.resizeTimer);
     }
 

src/plugins/condition/Condition.js

@@ -65,6 +65,9 @@ export default class Condition extends EventEmitter {
 
     this.trigger = conditionConfiguration.configuration.trigger;
     this.summary = '';
+    this.handleCriterionUpdated = this.handleCriterionUpdated.bind(this);
+    this.handleOldTelemetryCriterion = this.handleOldTelemetryCriterion.bind(this);
+    this.handleTelemetryStaleness = this.handleTelemetryStaleness.bind(this);
   }
 
   updateResult(datum) {
@@ -195,15 +198,15 @@ export default class Condition extends EventEmitter {
     if (found) {
       const newCriterionConfiguration = this.generateCriterion(criterionConfiguration);
       let newCriterion = new TelemetryCriterion(newCriterionConfiguration, this.openmct);
-      newCriterion.on('criterionUpdated', (obj) => this.handleCriterionUpdated(obj));
+      newCriterion.on('criterionUpdated', this.handleCriterionUpdated);
-      newCriterion.on('telemetryIsOld', (obj) => this.handleOldTelemetryCriterion(obj));
+      newCriterion.on('telemetryIsOld', this.handleOldTelemetryCriterion);
-      newCriterion.on('telemetryStaleness', () => this.handleTelemetryStaleness());
+      newCriterion.on('telemetryStaleness', this.handleTelemetryStaleness);
 
       let criterion = found.item;
       criterion.unsubscribe();
-      criterion.off('criterionUpdated', (obj) => this.handleCriterionUpdated(obj));
+      criterion.off('criterionUpdated', this.handleCriterionUpdated);
-      criterion.off('telemetryIsOld', (obj) => this.handleOldTelemetryCriterion(obj));
+      criterion.off('telemetryIsOld', this.handleOldTelemetryCriterion);
-      newCriterion.off('telemetryStaleness', () => this.handleTelemetryStaleness());
+      newCriterion.off('telemetryStaleness', this.handleTelemetryStaleness);
       this.criteria.splice(found.index, 1, newCriterion);
     }
   }
@@ -212,9 +215,9 @@ export default class Condition extends EventEmitter {
     let found = this.findCriterion(id);
     if (found) {
       let criterion = found.item;
-      criterion.off('criterionUpdated', (obj) => this.handleCriterionUpdated(obj));
+      criterion.off('criterionUpdated', this.handleCriterionUpdated);
-      criterion.off('telemetryIsOld', (obj) => this.handleOldTelemetryCriterion(obj));
+      criterion.off('telemetryIsOld', this.handleOldTelemetryCriterion);
-      criterion.off('telemetryStaleness', () => this.handleTelemetryStaleness());
+      criterion.off('telemetryStaleness', this.handleTelemetryStaleness);
       criterion.destroy();
       this.criteria.splice(found.index, 1);
 

src/plugins/condition/components/ConditionCollection.vue

@@ -127,6 +127,7 @@ export default {
     this.composition.off('remove', this.removeTelemetryObject);
     if (this.conditionManager) {
       this.conditionManager.off('conditionSetResultUpdated', this.handleConditionSetResultUpdated);
+      this.conditionManager.off('noTelemetryObjects', this.emitNoTelemetryObjectEvent);
       this.conditionManager.destroy();
     }
 

src/plugins/conditionWidget/components/ConditionWidget.vue

@@ -81,7 +81,7 @@ export default {
       this.listenToConditionSetChanges();
     }
   },
-  beforeUnmount() {
+  unmounted() {
     this.stopListeningToConditionSetChanges();
   },
   methods: {

src/plugins/displayLayout/DisplayLayoutToolbar.js

@@ -170,7 +170,7 @@ define(['lodash'], function (_) {
                 if (form) {
                   showForm(form, name, selectionPath);
                 } else {
-                  selectionPath[0].context.addElement(name);
+                  openmct.objectViews.emit('contextAction', 'addElement', name);
                 }
               },
               key: 'add',
@@ -236,7 +236,6 @@ define(['lodash'], function (_) {
             icon: 'icon-trash',
             title: 'Delete the selected object',
             method: function () {
-              let removeItem = selectionPath[1].context.removeItem;
               let prompt = openmct.overlays.dialog({
                 iconClass: 'alert',
                 message: `Warning! This action will remove this item from the Display Layout. Do you want to continue?`,
@@ -245,7 +244,11 @@ define(['lodash'], function (_) {
                     label: 'OK',
                     emphasis: 'true',
                     callback: function () {
-                      removeItem(getAllTypes(selection));
+                      openmct.objectViews.emit(
+                        'contextAction',
+                        'removeItem',
+                        getAllTypes(selection)
+                      );
                       prompt.dismiss();
                     }
                   },
@@ -290,7 +293,12 @@ define(['lodash'], function (_) {
               }
             ],
             method: function (option) {
-              selectionPath[1].context.orderItem(option.value, getAllTypes(selectedObjects));
+              openmct.objectViews.emit(
+                'contextAction',
+                'orderItem',
+                option.value,
+                getAllTypes(selectedObjects)
+              );
             }
           };
         }
@@ -474,9 +482,7 @@ define(['lodash'], function (_) {
             icon: 'icon-duplicate',
             title: 'Duplicate the selected object',
             method: function () {
-              let duplicateItem = selectionPath[1].context.duplicateItem;
+              openmct.objectViews.emit('contextAction', 'duplicateItem', selection);
-
-              duplicateItem(selection);
             }
           };
         }
@@ -555,6 +561,7 @@ define(['lodash'], function (_) {
 
         function getViewSwitcherMenu(selectedParent, selectionPath, selection) {
           if (selection.length === 1) {
+            // eslint-disable-next-line no-unused-vars
             let displayLayoutContext = selectionPath[1].context;
             let selectedItemContext = selectionPath[0].context;
             let selectedItemType = selectedItemContext.item.type;
@@ -574,14 +581,18 @@ define(['lodash'], function (_) {
                 label: 'View type',
                 options: viewOptions,
                 method: function (option) {
-                  displayLayoutContext.switchViewType(selectedItemContext, option.value, selection);
+                  openmct.objectViews.emit(
+                    'contextAction',
+                    'switchViewType',
+                    selectedItemContext,
+                    option.value,
+                    selection
+                  );
                 }
               };
             }
           } else if (selection.length > 1) {
             if (areAllViews('telemetry-view', 'layoutItem.type', selection)) {
-              let displayLayoutContext = selectionPath[1].context;
-
               return {
                 control: 'menu',
                 domainObject: selectedParent,
@@ -590,12 +601,15 @@ define(['lodash'], function (_) {
                 label: 'View type',
                 options: APPLICABLE_VIEWS['telemetry-view-multi'],
                 method: function (option) {
-                  displayLayoutContext.mergeMultipleTelemetryViews(selection, option.value);
+                  openmct.objectViews.emit(
+                    'contextAction',
+                    'mergeMultipleTelemetryViews',
+                    selection,
+                    option.value
+                  );
                 }
               };
             } else if (areAllViews('telemetry.plot.overlay', 'item.type', selection)) {
-              let displayLayoutContext = selectionPath[1].context;
-
               return {
                 control: 'menu',
                 domainObject: selectedParent,
@@ -603,7 +617,12 @@ define(['lodash'], function (_) {
                 title: 'Merge into a stacked plot',
                 options: APPLICABLE_VIEWS['telemetry.plot.overlay-multi'],
                 method: function (option) {
-                  displayLayoutContext.mergeMultipleOverlayPlots(selection, option.value);
+                  openmct.objectViews.emit(
+                    'contextAction',
+                    'mergeMultipleOverlayPlots',
+                    selection,
+                    option.value
+                  );
                 }
               };
             }
@@ -627,7 +646,7 @@ define(['lodash'], function (_) {
             domainObject: displayLayoutContext.item,
             icon: ICON_GRID_SHOW,
             method: function () {
-              displayLayoutContext.toggleGrid();
+              openmct.objectViews.emit('contextAction', 'toggleGrid');
 
               this.icon = this.icon === ICON_GRID_SHOW ? ICON_GRID_HIDE : ICON_GRID_SHOW;
             },
@@ -653,7 +672,7 @@ define(['lodash'], function (_) {
 
         function showForm(formStructure, name, selectionPath) {
           openmct.forms.showForm(formStructure).then((changes) => {
-            selectionPath[0].context.addElement(name, changes);
+            openmct.objectViews.emit('contextAction', 'addElement', name, changes);
           });
         }
 

src/plugins/displayLayout/components/BoxView.vue

@@ -25,14 +25,16 @@
     :item="item"
     :grid-size="gridSize"
     :is-editing="isEditing"
-    @move="(gridDelta) => $emit('move', gridDelta)"
+    @move="move"
-    @endMove="() => $emit('endMove')"
+    @endMove="endMove"
   >
+    <template #content>
       <div
         class="c-box-view u-style-receiver js-style-receiver"
         :class="[styleClass]"
         :style="style"
       ></div>
+    </template>
   </layout-frame>
 </template>
 
@@ -115,10 +117,18 @@ export default {
       this.initSelect
     );
   },
-  unmounted() {
+  beforeUnmount() {
     if (this.removeSelectable) {
       this.removeSelectable();
     }
+  },
+  methods: {
+    move(gridDelta) {
+      this.$emit('move', gridDelta);
+    },
+    endMove() {
+      this.$emit('endMove');
+    }
   }
 };
 </script>

src/plugins/displayLayout/components/DisplayLayout.vue

@@ -144,7 +144,7 @@ function getItemDefinition(itemType, ...options) {
 
 export default {
   components: components,
-  inject: ['openmct', 'objectPath', 'options', 'objectUtils', 'currentView'],
+  inject: ['openmct', 'objectPath', 'options', 'currentView'],
   props: {
     domainObject: {
       type: Object,
@@ -221,13 +221,21 @@ export default {
     this.composition.load();
     this.gridDimensions = [this.$el.offsetWidth, this.$el.scrollHeight];
 
-    this.openmct.objects.observe(this.domainObject, 'configuration.items', (items) => {
+    this.unObserveItems = this.openmct.objects.observe(
-      this.layoutItems = items;
+      this.domainObject,
-    });
+      'configuration.items',
+      (items) => {
+        this.layoutItems = [...items];
+      }
+    );
 
     this.watchDisplayResize();
   },
-  unmounted() {
+  beforeUnmount() {
+    if (this.unObserveItems) {
+      this.unObserveItems();
+    }
+    this.unwatchDisplayResize();
     this.openmct.selection.off('change', this.setSelection);
     this.composition.off('add', this.addChild);
     this.composition.off('remove', this.removeChild);
@@ -251,9 +259,15 @@ export default {
       this.$el.click();
     },
     watchDisplayResize() {
-      const resizeObserver = new ResizeObserver(() => this.updateGrid());
+      this.unwatchDisplayResize();
+      this.resizeObserver = new ResizeObserver(this.updateGrid);
 
-      resizeObserver.observe(this.$el);
+      this.resizeObserver.observe(this.$el);
+    },
+    unwatchDisplayResize() {
+      if (this.resizeObserver) {
+        this.resizeObserver.disconnect();
+      }
     },
     addElement(itemType, element) {
       this.addItem(itemType + '-view', element);
@@ -623,7 +637,7 @@ export default {
           return this.openmct.objects.makeKeyString(item.identifier) !== keyString;
         }
       });
-      this.layoutItems = layoutItems;
+      this.layoutItems = [...layoutItems];
       this.mutate('configuration.items', layoutItems);
       this.clearSelection();
     },

src/plugins/displayLayout/components/EllipseView.vue

@@ -25,14 +25,16 @@
     :item="item"
     :grid-size="gridSize"
     :is-editing="isEditing"
-    @move="(gridDelta) => $emit('move', gridDelta)"
+    @move="move"
-    @endMove="() => $emit('endMove')"
+    @endMove="endMove"
   >
+    <template #content>
       <div
         class="c-ellipse-view u-style-receiver js-style-receiver"
         :class="[styleClass]"
         :style="style"
       ></div>
+    </template>
   </layout-frame>
 </template>
 
@@ -115,10 +117,18 @@ export default {
       this.initSelect
     );
   },
-  unmounted() {
+  beforeUnmount() {
     if (this.removeSelectable) {
       this.removeSelectable();
     }
+  },
+  methods: {
+    move(gridDelta) {
+      this.$emit('move', gridDelta);
+    },
+    endMove() {
+      this.$emit('endMove');
+    }
   }
 };
 </script>

src/plugins/displayLayout/components/ImageView.vue

@@ -25,10 +25,12 @@
     :item="item"
     :grid-size="gridSize"
     :is-editing="isEditing"
-    @move="(gridDelta) => $emit('move', gridDelta)"
+    @move="move"
-    @endMove="() => $emit('endMove')"
+    @endMove="endMove"
   >
-    <div class="c-image-view" :class="[styleClass]" :style="style"></div>
+    <template #content>
+      <div class="c-image-view" :style="style"></div>
+    </template>
   </layout-frame>
 </template>
 
@@ -118,10 +120,18 @@ export default {
       this.initSelect
     );
   },
-  unmounted() {
+  beforeUnmount() {
     if (this.removeSelectable) {
       this.removeSelectable();
     }
+  },
+  methods: {
+    move(gridDelta) {
+      this.$emit('move', gridDelta);
+    },
+    endMove() {
+      this.$emit('endMove');
+    }
   }
 };
 </script>

src/plugins/displayLayout/components/LayoutFrame.vue

@@ -29,7 +29,7 @@
     }"
     :style="style"
   >
-    <slot></slot>
+    <slot name="content"></slot>
     <div class="c-frame__move-bar" @mousedown.left="startMove($event)"></div>
   </div>
 </template>

src/plugins/displayLayout/components/SubobjectView.vue

@@ -20,13 +20,14 @@
  at runtime from the About dialog for additional information.
 -->
 <template>
-  <LayoutFrame
+  <layout-frame
     :item="item"
     :grid-size="gridSize"
     :is-editing="isEditing"
-    @move="(gridDelta) => $emit('move', gridDelta)"
+    @move="move"
-    @endMove="() => $emit('endMove')"
+    @endMove="endMove"
   >
+    <template #content>
       <ObjectFrame
         v-if="domainObject"
         ref="objectFrame"
@@ -37,7 +38,8 @@
         :layout-font-size="item.fontSize"
         :layout-font="item.font"
       />
-  </LayoutFrame>
+    </template>
+  </layout-frame>
 </template>
 
 <script>
@@ -104,8 +106,7 @@ export default {
   data() {
     return {
       domainObject: undefined,
-      currentObjectPath: [],
+      currentObjectPath: []
-      mutablePromise: undefined
     };
   },
   watch: {
@@ -168,6 +169,12 @@ export default {
           delete this.immediatelySelect;
         }
       });
+    },
+    move(gridDelta) {
+      this.$emit('move', gridDelta);
+    },
+    endMove() {
+      this.$emit('endMove');
     }
   }
 };

src/plugins/displayLayout/components/TelemetryView.vue

@@ -25,9 +25,10 @@
     :item="item"
     :grid-size="gridSize"
     :is-editing="isEditing"
-    @move="(gridDelta) => $emit('move', gridDelta)"
+    @move="move"
-    @endMove="() => $emit('endMove')"
+    @endMove="endMove"
   >
+    <template #content>
       <div
         v-if="domainObject"
         ref="telemetryViewWrapper"
@@ -61,6 +62,7 @@
           </div>
         </div>
       </div>
+    </template>
   </layout-frame>
 </template>
 
@@ -387,6 +389,12 @@ export default {
     async showToolTip() {
       const { BELOW } = this.openmct.tooltips.TOOLTIP_LOCATIONS;
       this.buildToolTip(await this.getObjectPath(), BELOW, 'telemetryViewWrapper');
+    },
+    move(gridDelta) {
+      this.$emit('move', gridDelta);
+    },
+    endMove() {
+      this.$emit('endMove');
     }
   }
 };

src/plugins/displayLayout/components/TextView.vue

@@ -25,9 +25,10 @@
     :item="item"
     :grid-size="gridSize"
     :is-editing="isEditing"
-    @move="(gridDelta) => $emit('move', gridDelta)"
+    @move="move"
-    @endMove="() => $emit('endMove')"
+    @endMove="endMove"
   >
+    <template #content>
       <div
         class="c-text-view u-style-receiver js-style-receiver"
         :data-font-size="item.fontSize"
@@ -37,6 +38,7 @@
       >
         <div class="c-text-view__text">{{ item.text }}</div>
       </div>
+    </template>
   </layout-frame>
 </template>
 
@@ -127,10 +129,18 @@ export default {
       this.initSelect
     );
   },
-  unmounted() {
+  beforeUnmount() {
     if (this.removeSelectable) {
       this.removeSelectable();
     }
+  },
+  methods: {
+    move(gridDelta) {
+      this.$emit('move', gridDelta);
+    },
+    endMove() {
+      this.$emit('endMove');
+    }
   }
 };
 </script>

src/plugins/displayLayout/plugin.js

@@ -20,14 +20,14 @@
  * at runtime from the About dialog for additional information.
  *****************************************************************************/
 
-import AlphaNumericFormatViewProvider from './AlphanumericFormatViewProvider.js';
+import mount from 'utils/mount';
+
 import CopyToClipboardAction from './actions/CopyToClipboardAction';
+import AlphaNumericFormatViewProvider from './AlphanumericFormatViewProvider.js';
 import DisplayLayout from './components/DisplayLayout.vue';
 import DisplayLayoutToolbar from './DisplayLayoutToolbar.js';
 import DisplayLayoutType from './DisplayLayoutType.js';
 import DisplayLayoutDrawingObjectTypes from './DrawingObjectTypes.js';
-import objectUtils from 'objectUtils';
-import mount from 'utils/mount';
 
 class DisplayLayoutView {
   constructor(openmct, domainObject, objectPath, options) {
@@ -37,7 +37,6 @@ class DisplayLayoutView {
     this.options = options;
 
     this.component = null;
-    this.app = null;
   }
 
   show(container, isEditing) {
@@ -51,7 +50,6 @@ class DisplayLayoutView {
           openmct: this.openmct,
           objectPath: this.objectPath,
           options: this.options,
-          objectUtils,
           currentView: this
         },
         data: () => {
@@ -83,20 +81,17 @@ class DisplayLayoutView {
   getSelectionContext() {
     return {
       item: this.domainObject,
-      supportsMultiSelect: true,
+      supportsMultiSelect: true
-      addElement: this.component && this.component.$refs.displayLayout.addElement,
-      removeItem: this.component && this.component.$refs.displayLayout.removeItem,
-      orderItem: this.component && this.component.$refs.displayLayout.orderItem,
-      duplicateItem: this.component && this.component.$refs.displayLayout.duplicateItem,
-      switchViewType: this.component && this.component.$refs.displayLayout.switchViewType,
-      mergeMultipleTelemetryViews:
-        this.component && this.component.$refs.displayLayout.mergeMultipleTelemetryViews,
-      mergeMultipleOverlayPlots:
-        this.component && this.component.$refs.displayLayout.mergeMultipleOverlayPlots,
-      toggleGrid: this.component && this.component.$refs.displayLayout.toggleGrid
     };
   }
 
+  contextAction() {
+    const action = arguments[0];
+    if (this.component && this.component.$refs.displayLayout[action]) {
+      this.component.$refs.displayLayout[action](...Array.from(arguments).splice(1));
+    }
+  }
+
   onEditModeChange(isEditing) {
     this.component.isEditing = isEditing;
   }
@@ -104,6 +99,7 @@ class DisplayLayoutView {
   destroy() {
     if (this._destroy) {
       this._destroy();
+      this.component = undefined;
     }
   }
 }

src/plugins/flexibleLayout/components/container.vue

@@ -122,7 +122,6 @@ export default {
   mounted() {
     let context = {
       item: this.$parent.domainObject,
-      addContainer: this.addContainer,
       type: 'container',
       containerId: this.container.id
     };

src/plugins/flexibleLayout/components/flexibleLayout.vue

@@ -164,16 +164,32 @@ export default {
     this.composition.on('remove', this.removeChildObject);
     this.composition.on('add', this.addFrame);
     this.composition.load();
-    this.openmct.objects.observe(this.domainObject, 'configuration.containers', (containers) => {
+    this.unObserveContainers = this.openmct.objects.observe(
+      this.domainObject,
+      'configuration.containers',
+      (containers) => {
         this.containers = containers;
-    });
+      }
-    this.openmct.objects.observe(this.domainObject, 'configuration.rowsLayout', (rowsLayout) => {
+    );
+    this.unObserveRowsLayout = this.openmct.objects.observe(
+      this.domainObject,
+      'configuration.rowsLayout',
+      (rowsLayout) => {
         this.rowsLayout = rowsLayout;
-    });
+      }
+    );
   },
   beforeUnmount() {
     this.composition.off('remove', this.removeChildObject);
     this.composition.off('add', this.addFrame);
+
+    if (this.unObserveContainers) {
+      this.unObserveContainers();
+    }
+
+    if (this.unObserveRowsLayout) {
+      this.unObserveRowsLayout();
+    }
   },
   methods: {
     containsObject(identifier) {

src/plugins/flexibleLayout/components/frame.vue

@@ -142,6 +142,9 @@ export default {
           childContext.item = this.domainObject;
           childContext.type = 'frame';
           childContext.frameId = this.frame.id;
+          if (this.unsubscribeSelection) {
+            this.unsubscribeSelection();
+          }
           this.unsubscribeSelection = this.openmct.selection.selectable(
             this.$refs.frame,
             childContext,

src/plugins/flexibleLayout/components/resizeHandle.vue

@@ -56,7 +56,7 @@ export default {
     document.addEventListener('dragend', this.unsetDragging);
     document.addEventListener('drop', this.unsetDragging);
   },
-  unmounted() {
+  beforeUnmount() {
     document.removeEventListener('dragstart', this.setDragging);
     document.removeEventListener('dragend', this.unsetDragging);
     document.removeEventListener('drop', this.unsetDragging);

src/plugins/flexibleLayout/flexibleLayoutViewProvider.js

@@ -77,12 +77,15 @@ export default class FlexibleLayoutViewProvider {
       getSelectionContext() {
         return {
           item: domainObject,
-          addContainer: component.$refs.flexibleLayout.addContainer,
-          deleteContainer: component.$refs.flexibleLayout.deleteContainer,
-          deleteFrame: component.$refs.flexibleLayout.deleteFrame,
           type: 'flexible-layout'
         };
       },
+      contextAction() {
+        const action = arguments[0];
+        if (component && component.$refs.flexibleLayout[action]) {
+          component.$refs.flexibleLayout[action](...Array.from(arguments).splice(1));
+        }
+      },
       onEditModeChange(isEditing) {
         component.isEditing = isEditing;
       },

src/plugins/flexibleLayout/toolbarProvider.js

@@ -89,8 +89,6 @@ function ToolbarProvider(openmct) {
           control: 'button',
           domainObject: primary.context.item,
           method: function () {
-            let deleteFrameAction = tertiary.context.deleteFrame;
-
             let prompt = openmct.overlays.dialog({
               iconClass: 'alert',
               message: `This action will remove this frame from this Flexible Layout. Do you want to continue?`,
@@ -99,7 +97,11 @@ function ToolbarProvider(openmct) {
                   label: 'OK',
                   emphasis: 'true',
                   callback: function () {
-                    deleteFrameAction(primary.context.frameId);
+                    openmct.objectViews.emit(
+                      'contextAction',
+                      'deleteFrame',
+                      primary.context.frameId
+                    );
                     prompt.dismiss();
                   }
                 },
@@ -136,7 +138,9 @@ function ToolbarProvider(openmct) {
         addContainer = {
           control: 'button',
           domainObject: tertiary.context.item,
-          method: tertiary.context.addContainer,
+          method: function () {
+            openmct.objectViews.emit('contextAction', 'addContainer', ...arguments);
+          },
           key: 'add',
           icon: 'icon-plus-in-rect',
           title: 'Add Container'
@@ -152,7 +156,6 @@ function ToolbarProvider(openmct) {
           control: 'button',
           domainObject: primary.context.item,
           method: function () {
-            let removeContainer = secondary.context.deleteContainer;
             let containerId = primary.context.containerId;
 
             let prompt = openmct.overlays.dialog({
@@ -164,7 +167,7 @@ function ToolbarProvider(openmct) {
                   label: 'OK',
                   emphasis: 'true',
                   callback: function () {
-                    removeContainer(containerId);
+                    openmct.objectViews.emit('contextAction', 'deleteContainer', containerId);
                     prompt.dismiss();
                   }
                 },
@@ -185,7 +188,9 @@ function ToolbarProvider(openmct) {
         addContainer = {
           control: 'button',
           domainObject: secondary.context.item,
-          method: secondary.context.addContainer,
+          method: function () {
+            openmct.objectViews.emit('contextAction', 'addContainer', ...arguments);
+          },
           key: 'add',
           icon: 'icon-plus-in-rect',
           title: 'Add Container'
@@ -198,7 +203,9 @@ function ToolbarProvider(openmct) {
         addContainer = {
           control: 'button',
           domainObject: primary.context.item,
-          method: primary.context.addContainer,
+          method: function () {
+            openmct.objectViews.emit('contextAction', 'addContainer', ...arguments);
+          },
           key: 'add',
           icon: 'icon-plus-in-rect',
           title: 'Add Container'

src/plugins/imagery/components/ImageryView.vue

@@ -727,7 +727,8 @@ export default {
       }
     }
 
-    this.stopListening(this.focusedImageWrapper, 'wheel', this.wheelZoom, this);
+    // remove all eventListeners
+    this.stopListening();
 
     Object.keys(this.imageryAnnotations).forEach((time) => {
       const imageAnnotationsForTime = this.imageryAnnotations[time];
@@ -1276,6 +1277,9 @@ export default {
       this.scrollHandler();
     },
     setSizedImageDimensions() {
+      if (!this.$refs.focusedImage) {
+        return;
+      }
       this.focusedImageNaturalAspectRatio =
         this.$refs.focusedImage.naturalWidth / this.$refs.focusedImage.naturalHeight;
       if (

src/plugins/imagery/components/ImageryViewMenuSwitcher.vue

@@ -27,9 +27,7 @@
       :class="iconClass"
       :title="title"
       @click="toggleMenu"
-    >
+    />
-      <span class="c-button__label"></span>
-    </button>
     <div v-show="showMenu" class="c-switcher-menu__content">
       <slot></slot>
     </div>

src/plugins/inspectorDataVisualization/DataVisualization.vue

@@ -44,7 +44,7 @@
         </span>
       </div>
 
-      <select class="c-inspector__data-pivot-range-selector" v-model="selectedDataRangeIndex">
+      <select v-model="selectedDataRangeIndex" class="c-inspector__data-pivot-range-selector">
         <option
           v-for="(dataRange, index) in descendingDataRanges"
           :key="index"
@@ -78,8 +78,8 @@
   </div>
 </template>
 <script>
-import NumericData from './NumericData.vue';
 import Imagery from './Imagery.vue';
+import NumericData from './NumericData.vue';
 
 const TIMESTAMP_VIEW_BUFFER = 30 * 1000;
 const timestampBufferText = `${TIMESTAMP_VIEW_BUFFER / 1000} seconds`;

src/plugins/inspectorDataVisualization/NumericData.vue

@@ -34,8 +34,9 @@
 </template>
 <script>
 import mount from 'utils/mount';
-import TelemetryFrame from './TelemetryFrame.vue';
+
 import Plot from '../plot/Plot.vue';
+import TelemetryFrame from './TelemetryFrame.vue';
 
 export default {
   inject: ['openmct', 'domainObject', 'timeFormatter'],

src/plugins/inspectorViews/styles/SavedStylesInspectorView.vue

@@ -42,6 +42,10 @@ export default {
   },
   unmounted() {
     this.openmct.selection.off('change', this.updateSelection);
+    if (this.destroy) {
+      this.destroy();
+      this.$el.innerHTML = '';
+    }
   },
   methods: {
     updateSelection(selection) {

src/plugins/inspectorViews/styles/StylesInspectorView.vue

@@ -55,7 +55,7 @@ export default {
   mounted() {
     this.openmct.editor.on('isEditing', this.setEditMode);
   },
-  beforeUnmounted() {
+  beforeUnmount() {
     this.openmct.editor.off('isEditing', this.setEditMode);
   },
   methods: {

src/plugins/notebook/components/NotebookEntry.vue

@@ -293,7 +293,7 @@ export default {
   },
   beforeUnmount() {
     if (this.embedsWrapperResizeObserver) {
-      this.embedsWrapperResizeObserver.unobserve(this.$refs.embedsWrapper);
+      this.embedsWrapperResizeObserver.disconnect();
     }
   },
   methods: {

src/plugins/plot/MctPlot.vue

@@ -395,11 +395,7 @@ export default {
     );
 
     this.openmct.objectViews.on('clearData', this.clearData);
-    this.$on('loadingComplete', () => {
+    this.$on('loadingComplete', this.loadAnnotationsIfAllowed);
-      if (this.annotationViewingAndEditingAllowed) {
-        this.loadAnnotations();
-      }
-    });
     this.openmct.selection.on('change', this.updateSelection);
     this.yAxisListWithRange = [this.config.yAxis, ...this.config.additionalYAxes];
 
@@ -414,6 +410,7 @@ export default {
     document.removeEventListener('keydown', this.handleKeyDown);
     document.removeEventListener('keyup', this.handleKeyUp);
     document.body.removeEventListener('click', this.cancelSelection);
+    this.$off('loadingComplete', this.loadAnnotationsIfAllowed);
     this.destroy();
   },
   methods: {
@@ -468,9 +465,7 @@ export default {
         const currentXaxis = this.config.xAxis.get('displayRange');
         const currentYaxis = this.config.yAxis.get('displayRange');
         if (!currentXaxis || !currentYaxis) {
-          this.$once('loadingComplete', () => {
+          this.$once('loadingComplete', resolve);
-            resolve();
-          });
         } else {
           resolve();
         }
@@ -566,31 +561,10 @@ export default {
       const yAxisId = series.get('yAxisId');
       this.updateAxisUsageCount(yAxisId, 1);
       this.seriesModels[index] = series;
-      this.listenTo(
+      this.listenTo(series, 'change:xKey', this.setDisplayRange.bind(this, series), this);
-        series,
+      this.listenTo(series, 'change:yKey', this.loadSeriesData.bind(this, series), this);
-        'change:xKey',
-        (xKey) => {
-          this.setDisplayRange(series, xKey);
-        },
-        this
-      );
-      this.listenTo(
-        series,
-        'change:yKey',
-        () => {
-          this.loadSeriesData(series);
-        },
-        this
-      );
 
-      this.listenTo(
+      this.listenTo(series, 'change:interpolate', this.loadSeriesData.bind(this, series), this);
-        series,
-        'change:interpolate',
-        () => {
-          this.loadSeriesData(series);
-        },
-        this
-      );
       this.listenTo(series, 'change:yAxisId', this.updateTicksAndSeriesForYAxis, this);
 
       this.loadSeriesData(series);
@@ -622,6 +596,11 @@ export default {
         foundYAxis.seriesCount = foundYAxis.seriesCount + updateCountBy;
       }
     },
+    loadAnnotationsIfAllowed() {
+      if (this.annotationViewingAndEditingAllowed) {
+        this.loadAnnotations();
+      }
+    },
     async loadAnnotations() {
       if (!this.openmct.annotation.getAvailableTags().length) {
         // don't bother loading annotations if there are no tags
@@ -993,9 +972,6 @@ export default {
 
       this.config.yAxisLabel = this.config.yAxis.get('label');
 
-      this.cursorGuideVertical = this.$refs.cursorGuideVertical;
-      this.cursorGuideHorizontal = this.$refs.cursorGuideHorizontal;
-
       this.listenTo(this.config.xAxis, 'change:displayRange', this.onXAxisChange, this);
       this.yAxisListWithRange.forEach((yAxis) => {
         this.listenTo(yAxis, 'change:displayRange', this.onYAxisChange.bind(this, yAxis.id), this);
@@ -1123,8 +1099,8 @@ export default {
     },
 
     updateCrosshairs(event) {
-      this.cursorGuideVertical.style.left = event.clientX - this.chartElementBounds.x + 'px';
+      this.$refs.cursorGuideVertical.style.left = event.clientX - this.chartElementBounds.x + 'px';
-      this.cursorGuideHorizontal.style.top = event.clientY - this.chartElementBounds.y + 'px';
+      this.$refs.cursorGuideHorizontal.style.top = event.clientY - this.chartElementBounds.y + 'px';
     },
 
     trackChartElementBounds(event) {
@@ -1891,6 +1867,10 @@ export default {
         configStore.deleteStore(this.config.id);
       }
 
+      this.config = {};
+      this.canvas = undefined;
+      this.abortController = undefined;
+
       this.stopListening();
 
       if (this.checkForSize) {

src/plugins/plot/Plot.vue

@@ -178,7 +178,7 @@ export default {
     this.stalenessSubscription = {};
     this.loadComposition();
   },
-  beforeUnmount() {
+  unmounted() {
     this.destroy();
   },
   methods: {
@@ -258,6 +258,7 @@ export default {
         this.compositionCollection.off('remove', this.removeItem);
       }
 
+      this.imageExporter = null;
       this.stopListening();
     },
     exportJPG() {

src/plugins/plot/chart/MctChart.vue

@@ -26,7 +26,20 @@
   <div class="gl-plot-chart-area">
     <span v-html="canvasTemplate"></span>
     <span v-html="canvasTemplate"></span>
-    <div ref="limitArea" class="js-limit-area"></div>
+    <div ref="limitArea" class="js-limit-area">
+      <limit-label
+        v-for="(limitLabel, index) in visibleLimitLabels"
+        :key="index"
+        :point="limitLabel.point"
+        :limit="limitLabel.limit"
+      ></limit-label>
+      <limit-line
+        v-for="(limitLine, index) in visibleLimitLines"
+        :key="index"
+        :point="limitLine.point"
+        :limit="limitLine.limit"
+      ></limit-line>
+    </div>
   </div>
 </template>
 
@@ -86,6 +99,7 @@ const HANDLED_ATTRIBUTES = {
 };
 
 export default {
+  components: { LimitLine, LimitLabel },
   inject: ['openmct', 'domainObject', 'path'],
   props: {
     rectangles: {
@@ -132,7 +146,9 @@ export default {
   data() {
     return {
       canvasTemplate:
-        '<canvas style="position: absolute; background: none; width: 100%; height: 100%;"></canvas>'
+        '<canvas style="position: absolute; background: none; width: 100%; height: 100%;"></canvas>',
+      visibleLimitLabels: [],
+      visibleLimitLines: []
     };
   },
   watch: {
@@ -392,6 +408,8 @@ export default {
       this.stopListening();
       this.lines.forEach((line) => line.destroy());
       this.limitLines.forEach((line) => line.destroy());
+      this.pointSets.forEach((pointSet) => pointSet.destroy());
+      this.alarmSets.forEach((alarmSet) => alarmSet.destroy());
       DrawLoader.releaseDrawAPI(this.drawAPI);
     },
     resetYOffsetAndSeriesDataForYAxis(yAxisId) {
@@ -699,7 +717,6 @@ export default {
       alarmSets.forEach(this.drawAlarmPoints, this);
     },
     updateLimitLines() {
-      Array.from(this.$refs.limitArea.children).forEach((el) => el.remove());
       this.config.series.models.forEach((series) => {
         const yAxisId = series.get('yAxisId');
 
@@ -720,8 +737,11 @@ export default {
       }
 
       let limitPointOverlap = [];
+      //reset
+      this.visibleLimitLabels = [];
+      this.visibleLimitLines = [];
+
       this.limitLines.forEach((limitLine) => {
-        let limitContainerEl = this.$refs.limitArea;
         limitLine.limits.forEach((limit) => {
           if (series.keyString !== limit.seriesKey) {
             return;
@@ -731,31 +751,43 @@ export default {
           if (showLabels) {
             const overlap = this.getLimitOverlap(limit, limitPointOverlap);
             limitPointOverlap.push(overlap);
-            let limitLabelEl = this.getLimitLabel(limit, overlap);
+            this.visibleLimitLabels.push(this.getLimitProps(limit, overlap));
-            limitContainerEl.appendChild(limitLabelEl);
           }
 
-          let limitEl = this.getLimitElement(limit);
+          this.visibleLimitLines.push(this.getLimitElementProps(limit));
-          limitContainerEl.appendChild(limitEl);
         }, this);
       });
     },
     showLabels(seriesKey) {
       return this.showLimitLineLabels?.seriesKey === seriesKey;
     },
+    getLimitElementProps(limit) {
+      let point = {
+        left: 0,
+        top: this.drawAPI.y(limit.point.y)
+      };
+
+      return {
+        point,
+        limit
+      };
+    },
     getLimitElement(limit) {
       let point = {
         left: 0,
         top: this.drawAPI.y(limit.point.y)
       };
-      const { vNode } = mount(LimitLine, {
+      const { vNode, destroy } = mount(LimitLine, {
         props: {
           point,
           limit
         }
       });
 
-      return vNode.el;
+      return {
+        el: vNode.el,
+        destroy
+      };
     },
     getLimitOverlap(limit, overlapMap) {
       //calculate if limit lines are too close to each other
@@ -786,19 +818,32 @@ export default {
         overlapTop: limitTop
       };
     },
+    getLimitProps(limit, overlap) {
+      let point = {
+        left: 0,
+        top: this.drawAPI.y(limit.point.y)
+      };
+      return {
+        limit: Object.assign({}, overlap, limit),
+        point
+      };
+    },
     getLimitLabel(limit, overlap) {
       let point = {
         left: 0,
         top: this.drawAPI.y(limit.point.y)
       };
-      const { vNode } = mount(LimitLabel, {
+      const { vNode, destroy } = mount(LimitLabel, {
         props: {
           limit: Object.assign({}, overlap, limit),
           point
         }
       });
 
-      return vNode.el;
+      return {
+        el: vNode.el,
+        destroy
+      };
     },
     drawAlarmPoints(alarmSet) {
       this.drawAPI.drawLimitPoints(

src/plugins/plot/configuration/LegendModel.js

@@ -59,4 +59,8 @@ export default class LegendModel extends Model {
       showLegendsForChildren: true
     };
   }
+
+  destroy() {
+    this.stopListening();
+  }
 }

src/plugins/plot/configuration/PlotConfigurationModel.js

@@ -168,8 +168,10 @@ export default class PlotConfigurationModel extends Model {
   onDestroy() {
     this.xAxis.destroy();
     this.yAxis.destroy();
+    this.additionalYAxes.forEach((additionalYAxis) => additionalYAxis.destroy());
     this.series.destroy();
     this.legend.destroy();
+    this.stopListening();
     if (this.removeMutationListener) {
       this.removeMutationListener();
     }

src/plugins/plot/configuration/PlotSeries.js

@@ -134,7 +134,9 @@ export default class PlotSeries extends Model {
    * @override
    */
   destroy() {
+    //this triggers Model.destroy which in turn triggers destroy methods for other classes.
     super.destroy();
+    this.stopListening();
     this.openmct.time.off('bounds', this.updateLimits);
 
     if (this.unsubscribe) {
@@ -148,6 +150,8 @@ export default class PlotSeries extends Model {
     if (this.removeMutationListener) {
       this.removeMutationListener();
     }
+
+    configStore.deleteStore(this.dataStoreId);
   }
 
   /**

src/plugins/plot/configuration/SeriesCollection.js

@@ -186,6 +186,12 @@ export default class SeriesCollection extends Collection {
       );
     })[0];
   }
+
+  destroy() {
+    super.destroy();
+    this.plot = undefined;
+    this.stopListening();
+  }
 }
 
 /**

src/plugins/plot/configuration/XAxisModel.js

@@ -111,6 +111,11 @@ export default class XAxisModel extends Model {
 
     return defaultModel;
   }
+
+  destroy() {
+    this.plot = undefined;
+    this.stopListening();
+  }
 }
 
 /** @typedef {any} TODO */

src/plugins/plot/configuration/YAxisModel.js

@@ -384,6 +384,11 @@ export default class YAxisModel extends Model {
       range: options.model?.range
     };
   }
+
+  destroy() {
+    this.plot = undefined;
+    this.stopListening();
+  }
 }
 
 /** @typedef {any} TODO */

src/plugins/plot/draw/DrawWebGL.js

@@ -151,6 +151,8 @@ DrawWebGL.prototype.initContext = function () {
 };
 
 DrawWebGL.prototype.destroy = function () {
+  this.canvas = undefined;
+  this.overlay = undefined;
   this.stopListening();
 };
 

src/plugins/plot/stackedPlot/StackedPlot.vue

@@ -212,6 +212,8 @@ export default {
       this.composition.off('reorder', this.compositionReorder);
 
       this.stopListening();
+      const configId = this.openmct.objects.makeKeyString(this.domainObject.identifier);
+      configStore.deleteStore(configId);
     },
 
     addChild(child) {

src/plugins/plot/stackedPlot/StackedPlotItem.vue

@@ -133,6 +133,9 @@ export default {
       this.removeSelectable();
     }
 
+    const configId = this.openmct.objects.makeKeyString(this.childObject.identifier);
+    configStore.deleteStore(configId);
+
     if (this._destroy) {
       this._destroy();
     }

src/plugins/summaryWidget/src/Condition.js

@@ -1,3 +1,24 @@
+/*****************************************************************************
+ * Open MCT, Copyright (c) 2014-2023, 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.
+ *****************************************************************************/
 define([
   '../res/conditionTemplate.html',
   './input/ObjectSelect',
@@ -42,9 +63,6 @@ define([
     this.selects = {};
     this.valueInputs = [];
 
-    this.remove = this.remove.bind(this);
-    this.duplicate = this.duplicate.bind(this);
-
     const self = this;
 
     /**
@@ -65,6 +83,9 @@ define([
       });
     }
 
+    this.handleObjectChange = (value) => onSelectChange(value, 'object');
+    this.handleKeyChange = (value) => onSelectChange(value, 'key');
+
     /**
      * Event handler for this conditions value inputs
      * @param {Event} event The oninput event that triggered this callback
@@ -99,12 +120,8 @@ define([
       }
     );
 
-    this.selects.object.on('change', function (value) {
+    this.selects.object.on('change', this.handleObjectChange);
-      onSelectChange(value, 'object');
+    this.selects.key.on('change', this.handleKeyChange);
-    });
-    this.selects.key.on('change', function (value) {
-      onSelectChange(value, 'key');
-    });
 
     Object.values(this.selects).forEach(function (select) {
       self.domElement.querySelector('.t-configuration').append(select.getDOM());
@@ -143,6 +160,8 @@ define([
    * remove callbacks
    */
   Condition.prototype.remove = function () {
+    this.selects.object.off('change', this.handleObjectChange);
+    this.selects.key.off('change', this.handleKeyChange);
     this.eventEmitter.emit('remove', this.index);
     this.destroy();
   };

src/plugins/summaryWidget/src/input/Select.js

@@ -61,6 +61,20 @@ define([
     }
   };
 
+  /**
+   * Unregister a callback from this select.
+   * @param {string} event The key for the event to stop listening to
+   * @param {function} callback The function to unregister
+   * @param {Object} context A reference to a scope to use as the context for the callback function
+   */
+  Select.prototype.off = function (event, callback, context) {
+    if (this.supportedCallbacks.includes(event)) {
+      this.eventEmitter.off(event, callback, context || this);
+    } else {
+      throw new Error('Unsupported event type: ' + event);
+    }
+  };
+
   /**
    * Update the select element in the view from the current state of the data
    * model

src/plugins/tabs/components/tabs.vue

@@ -160,7 +160,8 @@ export default {
       this.updateInternalDomainObject
     );
 
-    this.openmct.router.on('change:params', this.updateCurrentTab.bind(this));
+    this.updateCurrentTab = this.updateCurrentTab.bind(this);
+    this.openmct.router.on('change:params', this.updateCurrentTab);
 
     this.RemoveAction = new RemoveAction(this.openmct);
     document.addEventListener('dragstart', this.dragstart);
@@ -183,7 +184,7 @@ export default {
     this.unsubscribe();
     this.clearCurrentTabIndexFromURL();
 
-    this.openmct.router.off('change:params', this.updateCurrentTab.bind(this));
+    this.openmct.router.off('change:params', this.updateCurrentTab);
 
     document.removeEventListener('dragstart', this.dragstart);
     document.removeEventListener('dragend', this.dragend);

src/plugins/timeline/TimelineObjectView.vue

@@ -90,6 +90,10 @@ export default {
       this.removeSelectable();
     }
 
+    if (this.removeStatusListener) {
+      this.removeStatusListener();
+    }
+
     if (this.mutablePromise) {
       this.mutablePromise.then(() => {
         this.openmct.objects.destroyMutable(this.domainObject);

src/ui/components/ObjectFrame.vue

@@ -208,13 +208,13 @@ export default {
 
       this.actionCollection = actionCollection;
       this.actionCollection.on('update', this.updateActionItems);
-      this.updateActionItems(this.actionCollection.applicableActions);
+      this.updateActionItems();
     },
     unlistenToActionCollection() {
       this.actionCollection.off('update', this.updateActionItems);
       delete this.actionCollection;
     },
-    updateActionItems(actionItems) {
+    updateActionItems() {
       const statusBarItems = this.actionCollection.getStatusBarActions();
       this.statusBarItems = this.openmct.menus.actionsToMenuItems(
         statusBarItems,

src/ui/components/ObjectView.vue

@@ -90,7 +90,7 @@ export default {
       return classes;
     }
   },
-  unmounted() {
+  beforeUnmount() {
     this.clear();
     if (this.releaseEditModeHandler) {
       this.releaseEditModeHandler();
@@ -113,6 +113,13 @@ export default {
       this.actionCollection.destroy();
       delete this.actionCollection;
     }
+    this.$refs.objectViewWrapper.removeEventListener('dragover', this.onDragOver, {
+      capture: true
+    });
+    this.$refs.objectViewWrapper.removeEventListener('drop', this.editIfEditable, {
+      capture: true
+    });
+    this.$refs.objectViewWrapper.removeEventListener('drop', this.addObjectToParent);
   },
   created() {
     this.debounceUpdateView = _.debounce(this.updateView, 10);
@@ -136,6 +143,7 @@ export default {
     clear() {
       if (this.currentView) {
         this.currentView.destroy();
+
         if (this.$refs.objectViewWrapper) {
           this.$refs.objectViewWrapper.innerHTML = '';
         }
@@ -167,6 +175,7 @@ export default {
       this.triggerUnsubscribeFromStaleness();
 
       this.openmct.objectViews.off('clearData', this.clearData);
+      this.openmct.objectViews.off('contextAction', this.performContextAction);
     },
     getStyleReceiver() {
       let styleReceiver;
@@ -287,6 +296,7 @@ export default {
       }
 
       this.openmct.objectViews.on('clearData', this.clearData);
+      this.openmct.objectViews.on('contextAction', this.performContextAction);
 
       this.$nextTick(() => {
         this.updateStyle(this.styleRuleManager?.currentStyle);
@@ -309,10 +319,6 @@ export default {
     show(object, viewKey, immediatelySelect, currentObjectPath) {
       this.updateStyle();
 
-      if (this.unlisten) {
-        this.unlisten();
-      }
-
       if (this.removeSelectable) {
         this.removeSelectable();
         delete this.removeSelectable;
@@ -461,6 +467,11 @@ export default {
         }
       }
     },
+    performContextAction() {
+      if (this.currentView.contextAction) {
+        this.currentView.contextAction(...arguments);
+      }
+    },
     isEditingAllowed() {
       let browseObject = this.openmct.layout.$refs.browseObject.domainObject;
       let objectPath = this.currentObjectPath || this.objectPath;

src/ui/layout/pane.vue

@@ -105,8 +105,9 @@ export default {
     this.styleProp = this.type === 'horizontal' ? 'width' : 'height';
   },
   created() {
+    this.handleHideUrl = this.handleHideUrl.bind(this);
     // Hide tree and/or inspector pane if specified in URL
-    this.openmct.router.on('change:params', this.handleHideUrl.bind(this));
+    this.openmct.router.on('change:params', this.handleHideUrl);
   },
   async mounted() {
     if (this.persistPosition) {
@@ -121,6 +122,9 @@ export default {
       this.handleHideUrl();
     }
   },
+  beforeUnmount() {
+    this.openmct.router.off('change:params', this.handleHideUrl);
+  },
   methods: {
     addHideParam(target) {
       this.openmct.router.setSearchParam(target, 'true');

src/ui/mixins/context-menu-gesture.js

@@ -16,6 +16,7 @@ export default {
     };
   },
   mounted() {
+    this.unobserveObjects = {};
     //TODO: touch support
     this.$nextTick(() => {
       this.$refs.root.addEventListener('contextmenu', this.showContextMenu);
@@ -29,19 +30,24 @@ export default {
 
     this.objectPath.forEach((object) => {
       if (object) {
-        const unobserve = this.openmct.objects.observe(
+        const key = this.openmct.objects.makeKeyString(object.identifier);
+        this.unobserveObjects[key] = this.openmct.objects.observe(
           object,
           '*',
           updateObject.bind(this, object)
         );
-        this.$once('hook:unmounted', unobserve);
       }
     });
   },
   beforeUnmount() {
+    this.removeListeners();
     this.$refs.root.removeEventListener('contextMenu', this.showContextMenu);
   },
   methods: {
+    removeListeners() {
+      Object.values(this.unobserveObjects).forEach((unobserve) => unobserve());
+      this.unobserveObjects = {};
+    },
     showContextMenu(event) {
       if (this.readOnly) {
         return;

src/ui/toolbar/Toolbar.vue

@@ -89,7 +89,7 @@ export default {
     // for edit mode changes and update toolbars if necessary.
     this.openmct.editor.on('isEditing', this.handleEditing);
   },
-  unmounted() {
+  beforeUnmount() {
     this.openmct.selection.off('change', this.handleSelection);
     this.openmct.editor.off('isEditing', this.handleEditing);
     this.removeListeners();

src/utils/mount.js

@@ -1,26 +1,25 @@
-import { h, render } from 'vue';
+import { createApp, defineComponent } from 'vue';
 
-export default function mount(component, { props, children, element, app } = {}) {
+export default function mount(component, { props, children, element } = {}) {
   let el = element;
-
+  if (!el) {
-  let vNode = h(component, props, children);
+    el = document.createElement('div');
-  if (app && app._context) {
-    vNode.appContext = app._context;
-  }
-  if (el) {
-    render(vNode, el);
-  } else if (typeof document !== 'undefined') {
-    render(vNode, (el = document.createElement('div')));
   }
+  let vueComponent = defineComponent(component);
+  let app = createApp(vueComponent);
+  let mountedComponentInstance = app.mount(el);
 
   // eslint-disable-next-line func-style
   const destroy = () => {
-    if (el) {
+    app.unmount();
-      render(null, el);
-    }
-    el = null;
-    vNode = null;
   };
 
-  return { vNode, destroy, el };
+  return {
+    vNode: {
+      componentInstance: mountedComponentInstance,
+      el: mountedComponentInstance.$el
+    },
+    destroy,
+    el
+  };
 }