feat(browser): Add lazyLoadIntegration utility

dev-packages/browser-integration-tests/suites/integrations/lazyLoad/existingIntegration/init.js

@@ -0,0 +1,13 @@
+import * as Sentry from '@sentry/browser';
+import { httpClientIntegration } from '@sentry/browser';
+
+window.Sentry = {
+  ...Sentry,
+  // This would be done by the CDN bundle otherwise
+  httpClientIntegration: httpClientIntegration,
+};
+
+Sentry.init({
+  dsn: 'https://[email protected]/1337',
+  integrations: [],
+});

dev-packages/browser-integration-tests/suites/integrations/lazyLoad/existingIntegration/subject.js

@@ -0,0 +1,7 @@
+window._testLazyLoadIntegration = async function run() {
+  const integration = await window.Sentry.lazyLoadIntegration('httpClientIntegration');
+
+  window.Sentry.getClient()?.addIntegration(integration());
+
+  window._integrationLoaded = true;
+};

dev-packages/browser-integration-tests/suites/integrations/lazyLoad/existingIntegration/test.ts

@@ -0,0 +1,24 @@
+import { expect } from '@playwright/test';
+
+import { sentryTest } from '../../../../utils/fixtures';
+
+sentryTest('it bails if the integration is already loaded', async ({ getLocalTestUrl, page }) => {
+  const url = await getLocalTestUrl({ testDir: __dirname });
+
+  await page.goto(url);
+
+  const hasIntegration = await page.evaluate('!!window.Sentry.getClient()?.getIntegrationByName("HttpClient")');
+  expect(hasIntegration).toBe(false);
+
+  const scriptTagsBefore = await page.evaluate('document.querySelectorAll("script").length');
+
+  await page.evaluate('window._testLazyLoadIntegration()');
+  await page.waitForFunction('window._integrationLoaded');
+
+  const scriptTagsAfter = await page.evaluate('document.querySelectorAll("script").length');
+
+  const hasIntegration2 = await page.evaluate('!!window.Sentry.getClient()?.getIntegrationByName("HttpClient")');
+  expect(hasIntegration2).toBe(true);
+
+  expect(scriptTagsAfter).toBe(scriptTagsBefore);
+});

dev-packages/browser-integration-tests/suites/integrations/lazyLoad/validIntegration/init.js

@@ -0,0 +1,12 @@
+import * as Sentry from '@sentry/browser';
+
+window.Sentry = {
+  ...Sentry,
+  // Ensure this is _not_ set
+  httpClientIntegration: undefined,
+};
+
+Sentry.init({
+  dsn: 'https://[email protected]/1337',
+  integrations: [],
+});

dev-packages/browser-integration-tests/suites/integrations/lazyLoad/validIntegration/subject.js

@@ -0,0 +1,7 @@
+window._testLazyLoadIntegration = async function run() {
+  const integration = await window.Sentry.lazyLoadIntegration('httpClientIntegration');
+
+  window.Sentry.getClient()?.addIntegration(integration());
+
+  window._integrationLoaded = true;
+};

dev-packages/browser-integration-tests/suites/integrations/lazyLoad/validIntegration/test.ts

@@ -0,0 +1,24 @@
+import { expect } from '@playwright/test';
+
+import { sentryTest } from '../../../../utils/fixtures';
+
+sentryTest('it allows to lazy load an integration', async ({ getLocalTestUrl, page }) => {
+  const url = await getLocalTestUrl({ testDir: __dirname });
+
+  await page.goto(url);
+
+  const hasIntegration = await page.evaluate('!!window.Sentry.getClient()?.getIntegrationByName("HttpClient")');
+  expect(hasIntegration).toBe(false);
+
+  const scriptTagsBefore = await page.evaluate<number>('document.querySelectorAll("script").length');
+
+  await page.evaluate('window._testLazyLoadIntegration()');
+  await page.waitForFunction('window._integrationLoaded');
+
+  const scriptTagsAfter = await page.evaluate<number>('document.querySelectorAll("script").length');
+
+  const hasIntegration2 = await page.evaluate('!!window.Sentry.getClient()?.getIntegrationByName("HttpClient")');
+  expect(hasIntegration2).toBe(true);
+
+  expect(scriptTagsAfter).toBe(scriptTagsBefore + 1);
+});

packages/browser/src/client.ts

@@ -34,7 +34,10 @@ export type BrowserOptions = Options<BrowserTransportOptions> &
  */
 export type BrowserClientOptions = ClientOptions<BrowserTransportOptions> &
   BrowserClientReplayOptions &
-  BrowserClientProfilingOptions;
+  BrowserClientProfilingOptions & {
+    /** If configured, this URL will be used as base URL for lazy loading integration. */
+    cdnBaseUrl?: string;
+  };
 
 /**
  * The Sentry Browser SDK Client.

packages/browser/src/exports.ts

@@ -95,3 +95,5 @@ export { globalHandlersIntegration } from './integrations/globalhandlers';
 export { httpContextIntegration } from './integrations/httpcontext';
 export { linkedErrorsIntegration } from './integrations/linkederrors';
 export { browserApiErrorsIntegration } from './integrations/browserapierrors';
+
+export { lazyLoadIntegration } from './utils/lazyLoadIntegration';

packages/browser/src/utils/lazyLoadIntegration.ts

@@ -0,0 +1,77 @@
+import { SDK_VERSION, getClient } from '@sentry/core';
+import type { IntegrationFn } from '@sentry/types';
+import type { BrowserClient } from '../client';
+import { WINDOW } from '../helpers';
+
+// This is a map of integration function method to bundle file name.
+const LazyLoadableIntegrations = {
+  replayIntegration: 'replay',
+  replayCanvasIntegration: 'replay-canvas',
+  feedbackIntegration: 'feedback',
+  captureConsoleIntegration: 'captureconsole',
+  contextLinesIntegration: 'contextlines',
+  linkedErrorsIntegration: 'linkederrors',
+  debugIntegration: 'debug',
+  dedupeIntegration: 'dedupe',
+  extraErrorDataIntegration: 'extraerrordata',
+  httpClientIntegration: 'httpclient',
+  reportingObserverIntegration: 'reportingobserver',
+  rewriteFramesIntegration: 'rewriteframes',
+  sessionTimingIntegration: 'sessiontiming',
+} as const;
+
+const WindowWithMaybeIntegration = WINDOW as {
+  Sentry?: Partial<Record<keyof typeof LazyLoadableIntegrations, IntegrationFn>>;
+};
+
+/**
+ * Lazy load an integration from the CDN.
+ * Rejects if the integration cannot be loaded.
+ */
+export async function lazyLoadIntegration(name: keyof typeof LazyLoadableIntegrations): Promise<IntegrationFn> {
+  const bundle = LazyLoadableIntegrations[name];
+
+  if (!bundle || !WindowWithMaybeIntegration.Sentry) {
+    throw new Error(`Cannot lazy load integration: ${name}`);
+  }
+
+  // Bail if the integration already exists
+  const existing = WindowWithMaybeIntegration.Sentry[name];
+  if (typeof existing === 'function') {
+    return existing;
+  }
+
+  const url = getScriptURL(bundle);
+  const script = WINDOW.document.createElement('script');
+  script.src = url;
+  script.crossOrigin = 'anonymous';
+
+  const waitForLoad = new Promise<void>((resolve, reject) => {
+    script.addEventListener('load', () => resolve());
+    script.addEventListener('error', reject);
+  });
+
+  WINDOW.document.body.appendChild(script);
+
+  try {
+    await waitForLoad;
+  } catch {
+    throw new Error(`Error when loading integration: ${name}`);
+  }
+
+  const integrationFn = WindowWithMaybeIntegration.Sentry[name];
+
+  if (typeof integrationFn !== 'function') {
+    throw new Error(`Could not load integration: ${name}`);
+  }
+
+  return integrationFn;
+}
+
+function getScriptURL(bundle: string): string {
+  const client = getClient<BrowserClient>();
+  const options = client && client.getOptions();
+  const baseURL = (options && options.cdnBaseUrl) || 'https://browser.sentry-cdn.com';
+
+  return new URL(`/${SDK_VERSION}/${bundle}.min.js`, baseURL).toString();
+}

packages/browser/test/unit/utils/lazyLoadIntegration.test.ts

@@ -0,0 +1,83 @@
+import { TextDecoder, TextEncoder } from 'util';
+import { SDK_VERSION, lazyLoadIntegration } from '../../../src';
+import * as Sentry from '../../../src';
+const patchedEncoder = (!global.window.TextEncoder && (global.window.TextEncoder = TextEncoder)) || true;
+// @ts-expect-error patch the encoder on the window, else importing JSDOM fails (deleted in afterAll)
+const patchedDecoder = (!global.window.TextDecoder && (global.window.TextDecoder = TextDecoder)) || true;
+
+import { JSDOM } from 'jsdom';
+
+const globalDocument = global.document;
+const globalWindow = global.window;
+const globalLocation = global.location;
+
+describe('lazyLoadIntegration', () => {
+  beforeEach(() => {
+    const dom = new JSDOM('<body></body>', {
+      runScripts: 'dangerously',
+      resources: 'usable',
+    });
+
+    global.document = dom.window.document;
+    // @ts-expect-error need to override global document
+    global.window = dom.window;
+    global.location = dom.window.location;
+    // @ts-expect-error For testing sake
+    global.Sentry = undefined;
+  });
+
+  // Reset back to previous values
+  afterEach(() => {
+    global.document = globalDocument;
+    global.window = globalWindow;
+    global.location = globalLocation;
+  });
+
+  afterAll(() => {
+    // @ts-expect-error patch the encoder on the window, else importing JSDOM fails
+    patchedEncoder && delete global.window.TextEncoder;
+    // @ts-expect-error patch the encoder on the window, else importing JSDOM fails
+    patchedDecoder && delete global.window.TextDecoder;
+  });
+
+  test('it rejects invalid name', async () => {
+    // @ts-expect-error For testing sake - otherwise this bails out anyhow
+    global.Sentry = Sentry;
+
+    // @ts-expect-error we want to test this
+    await expect(() => lazyLoadIntegration('invalid!!!')).rejects.toThrow('Cannot lazy load integration: invalid!!!');
+  });
+
+  test('it rejects without global Sentry variable', async () => {
+    await expect(() => lazyLoadIntegration('httpClientIntegration')).rejects.toThrow(
+      'Cannot lazy load integration: httpClientIntegration',
+    );
+  });
+
+  test('it does not inject a script tag if integration already exists', async () => {
+    // @ts-expect-error For testing sake
+    global.Sentry = Sentry;
+
+    const integration = await lazyLoadIntegration('httpClientIntegration');
+
+    expect(integration).toBe(Sentry.httpClientIntegration);
+    expect(global.document.querySelectorAll('script')).toHaveLength(0);
+  });
+
+  test('it injects a script tag if integration is not yet loaded xxx', async () => {
+    // @ts-expect-error For testing sake
+    global.Sentry = {
+      ...Sentry,
+      httpClientIntegration: undefined,
+    };
+
+    // We do not await here, as this this does not seem to work with JSDOM :(
+    // We have browser integration tests to check that this actually works
+    void lazyLoadIntegration('httpClientIntegration');
+
+    expect(global.document.querySelectorAll('script')).toHaveLength(1);
+    expect(global.document.querySelector('script')?.src).toEqual(
+      `https://browser.sentry-cdn.com/${SDK_VERSION}/httpclient.min.js`,
+    );
+  });
+});