test: fix lti launch test

src/instructions/Instructions.test.jsx

@@ -793,8 +793,12 @@ describe('SequenceExamWrapper', () => {
   });
 
   it('Initiates an LTI launch in a new window when the user clicks the System Check button', async () => {
-    const windowSpy = jest.spyOn(window, 'open');
-    windowSpy.mockImplementation(() => ({}));
+    const { location } = window;
+    delete window.location;
+    const mockAssign = jest.fn();
+    window.location = {
+      assign: mockAssign,
+    };
     store.getState = () => ({
       examState: Factory.build('examState', {
         activeAttempt: {},
@@ -825,13 +829,16 @@ describe('SequenceExamWrapper', () => {
       { store },
     );
     fireEvent.click(screen.getByText('Start System Check'));
-    await waitFor(() => { expect(windowSpy).toHaveBeenCalledWith('http://localhost:18740/lti/start_proctoring/4321', '_blank'); });
+    await waitFor(() => { expect(mockAssign).toHaveBeenCalledWith('http://localhost:18740/lti/start_proctoring/4321'); });
     expect(softwareDownloadAttempt).toHaveBeenCalledWith(4321, false);
 
     // also validate start button works
     pollExamAttempt.mockReturnValue(Promise.resolve({ status: ExamStatus.READY_TO_START }));
     fireEvent.click(screen.getByText('Start Exam'));
     await waitFor(() => { expect(getExamAttemptsData).toHaveBeenCalled(); });
+
+    // restore window.location
+    window.location = location;
   });
 
   it('Shows correct download instructions for legacy rest provider if attempt status is created', () => {