fix: prevent error when there are no results for a given filter (#1257)

src/course-home/courseware-search/CoursewareResultsFilter.jsx

@@ -23,7 +23,7 @@ export const CoursewareSearchResultsFilter = ({ intl }) => {
   const lastSearch = useModel('contentSearchResults', courseId);
   const { filter: filterKeyword, setFilter } = useCoursewareSearchParams();
 
-  if (!lastSearch || !lastSearch?.results?.length) { return null; }
+  if (!lastSearch) { return null; }
 
   const { results: data = [] } = lastSearch;
 
@@ -40,7 +40,7 @@ export const CoursewareSearchResultsFilter = ({ intl }) => {
   const filters = useMemo(() => Object.keys(allowedFilterKeys).map((key) => ({
     key,
     label: intl.formatMessage(messages[`filter:${key}`]),
-    count: results[key].length,
+    count: results[key]?.length || 0,
   })), [results]);
 
   const activeKey = allowedFilterKeys[filterKeyword] ? filterKeyword : allFilterKey;

src/course-home/courseware-search/CoursewareResultsFilter.test.jsx

@@ -54,11 +54,14 @@ describe('CoursewareSearchResultsFilter', () => {
 
   describe('</CoursewareSearchResultsFilter />', () => {
     beforeEach(() => {
+      useCoursewareSearchParams.mockReturnValue(coursewareSearch);
+    });
+
+    afterEach(() => {
       jest.clearAllMocks();
     });
 
-    it('should render', async () => {
-      useCoursewareSearchParams.mockReturnValue(coursewareSearch);
+    it('should render without errors', async () => {
       useModel.mockReturnValue(searchResultsFactory());
 
       await renderComponent();
@@ -71,5 +74,27 @@ describe('CoursewareSearchResultsFilter', () => {
         expect(screen.queryByTestId('courseware-search-results-tabs-other')).toBeInTheDocument();
       });
     });
+
+    describe('when there are not results', () => {
+      it('should render without errors', async () => {
+        useModel.mockReturnValue(searchResultsFactory('blah', {
+          results: [],
+          filters: [],
+          total: 0,
+          maxScore: null,
+          ms: 5,
+        }));
+
+        await renderComponent();
+
+        await waitFor(() => {
+          expect(screen.queryByTestId('courseware-search-results-tabs-all')).toBeInTheDocument();
+          expect(screen.queryByTestId('courseware-search-results-tabs-text')).toBeInTheDocument();
+          expect(screen.queryByTestId('courseware-search-results-tabs-video')).toBeInTheDocument();
+          expect(screen.queryByTestId('courseware-search-results-tabs-sequence')).toBeInTheDocument();
+          expect(screen.queryByTestId('courseware-search-results-tabs-other')).toBeInTheDocument();
+        });
+      });
+    });
   });
 });

src/course-home/courseware-search/CoursewareSearchResults.jsx

@@ -15,7 +15,7 @@ const iconTypeMapping = {
 
 const defaultIcon = Article;
 
-const CoursewareSearchResults = ({ results }) => {
+const CoursewareSearchResults = ({ results = [] }) => {
   if (!results?.length) {
     return <CoursewareSearchEmpty />;
   }