fix(replay): Only call scope.getLastBreadcrumb if available

packages/replay/src/coreHandlers/handleScope.ts

@@ -26,7 +26,11 @@ export const handleScopeListener: (replay: ReplayContainer) => (scope: Scope) =>
  * An event handler to handle scope changes.
  */
 export function handleScope(scope: Scope): Breadcrumb | null {
-  const newBreadcrumb = scope.getLastBreadcrumb();
+  // TODO (v8): Remove this guard. This was put in place because we introduced
+  // Scope.getLastBreadcrumb mid-v7 which caused incompatibilities with older SDKs.
+  // For now, we'll just return null if the method doesn't exist but we should eventually
+  // get rid of this guard.
+  const newBreadcrumb = scope.getLastBreadcrumb && scope.getLastBreadcrumb();
 
   // Listener can be called when breadcrumbs have not changed, so we store the
   // reference to the last crumb and only return a crumb if it has changed

packages/replay/test/unit/coreHandlers/handleScope.test.ts

@@ -3,7 +3,12 @@ import type { Breadcrumb, Scope } from '@sentry/types';
 import * as HandleScope from '../../../src/coreHandlers/handleScope';
 
 describe('Unit | coreHandlers | handleScope', () => {
-  const mockHandleScope = jest.spyOn(HandleScope, 'handleScope');
+  let mockHandleScope: jest.SpyInstance;
+
+  beforeEach(() => {
+    mockHandleScope = jest.spyOn(HandleScope, 'handleScope');
+    mockHandleScope.mockClear();
+  });
 
   it('returns a breadcrumb only if last breadcrumb has changed', function () {
     const scope = {
@@ -47,4 +52,11 @@ describe('Unit | coreHandlers | handleScope', () => {
     expect(mockHandleScope).toHaveBeenCalledTimes(1);
     expect(mockHandleScope).toHaveReturnedWith(expect.objectContaining({ message: 'f00', category: 'console' }));
   });
+
+  it('returns null if the method does not exist on the scope', () => {
+    const scope = {} as unknown as Scope;
+    HandleScope.handleScope(scope);
+    expect(mockHandleScope).toHaveBeenCalledTimes(1);
+    expect(mockHandleScope).toHaveReturnedWith(null);
+  });
 });