anchor.diff:            generateInsertionOrder(
                 advertiserId, mediaPlanId1, ioId3, startDate, endDate, spending3),
           ];
  -      });
  -
  -      tearDown(() => clearInteractions(mockGoogleApiDart));
  -
  -      test('no advertiser id and no media plan id disables the populate button',
  +        verify(mockExcelDart.populate(expectedInput, any));
  +      });
  +
  +      test('valid ids displays the spinner when populate() is running',
             () async {
  -        await queryComponentPO.clickPopulate();
  -        verifyNever(mockGoogleApiDart.request(any));
  -      });
  -
  -      test('no advertiser id disables the populate button', () async {
  +        await queryComponentAccordionPO.typeAdvertiserId(advertiserId);
           await queryComponentAccordionPO.typeMediaPlanId(mediaPlanId1);
           await queryComponentPO.clickPopulate();
  -        verifyNever(mockGoogleApiDart.request(any));
  -      });
  -
  -      test('non-integer advertiser id disables the populate button', () async {
  -        await queryComponentAccordionPO.typeAdvertiserId('wrong-format-id');
  -        await queryComponentAccordionPO.typeMediaPlanId(mediaPlanId1);
  -        await queryComponentPO.clickPopulate();
  -        verifyNever(mockGoogleApiDart.request(any));
  -      });
  -
  -      test('no media plan id disables the populate button', () async {
  -        await queryComponentAccordionPO.typeAdvertiserId(advertiserId);
  -        await queryComponentPO.clickPopulate();
  -        verifyNever(mockGoogleApiDart.request(any));
  -      });
  -
  -      test('non-integer media plan id disables the populate button', () async {
  -        await queryComponentAccordionPO.typeAdvertiserId(advertiserId);
  -        await queryComponentAccordionPO.typeMediaPlanId('wrong-format-id');
  -        await queryComponentPO.clickPopulate();
  -        verifyNever(mockGoogleApiDart.request(any));
  -      });
  -
  -      test(
  -          'highlight underpacing unchecked invokes populate() with correct list of IOs',
  -          () async {
  -        await queryComponentAccordionPO.typeAdvertiserId(advertiserId);
  -        await queryComponentAccordionPO.typeMediaPlanId(mediaPlanId1);
  -        await queryComponentPO.clickPopulate();
  -
  -        // waits for the last operation execReportingDownload() to finish.
  -        await fixture
  -            .update((_) => reportCompleter.complete(generateReport(report2)));
  -        verify(mockExcelDart.populate(expectedInput, any));
  -      });
  -
  -      test(
  -          'correct ids invokes populate() and '
  -          'displays the spinner when populate() is running', () async {
  -        await queryComponentAccordionPO.typeAdvertiserId(advertiserId);
  -        await queryComponentAccordionPO.typeMediaPlanId(mediaPlanId1);
  -        await queryComponentPO.clickPopulate();
  -
  -        // waits for the fixture to update, but keeps populate() hanging.
  +
           await fixture.update();
           expect(queryComponentPO.populateButtonSpinner, isVisible);
         });
   
  -      test(
  -          'correct ids invokes populate() and '
  -          'hides the spinner when populate() finishes running', () async {
  +      test('valid ids hides the spinner when populate() finishes running',
  +          () async {
           await queryComponentAccordionPO.typeAdvertiserId(advertiserId);
           await queryComponentAccordionPO.typeMediaPlanId(mediaPlanId1);
           await queryComponentPO.clickPopulate();
   
  -        // waits for the last operation execReportingDownload() to finish.
           await fixture
               .update((_) => reportCompleter.complete(generateReport(report1)));
           expect(queryComponentPO.populateButtonSpinner, notExists);
  
positive.code:         when(mockGoogleApiDart
                  .request(argThat(isReportingDownloadRequestWith(downloadLink))))
              .thenAnswer((_) => reportCompleter.future);
  
          expectedInput = [
            generateInsertionOrder(
                advertiserId, mediaPlanId1, ioId1, startDate, endDate, spending1),
            generateInsertionOrder(
  
negative.code:     MockGoogleApiDart mockGoogleApiDart;
      MockExcelDart mockExcelDart;
  
      Completer<String> reportCompleter;
  
      setUp(() async {
  