test: add test to loading state

src/library-authoring/collections/LibraryCollectionPage.test.tsx

@@ -33,7 +33,7 @@ const path = '/library/:libraryId/*';
 const libraryTitle = mockContentLibrary.libraryData.title;
 const mockCollection = {
   collectionId: mockResult.results[2].hits[0].block_id,
-  collectionNeverLoads: 'collection-always-loading',
+  collectionNeverLoads: mockGetCollectionMetadata.collectionIdLoading,
   collectionNoComponents: 'collection-no-components',
   collectionEmpty: mockGetCollectionMetadata.collectionIdError,
 };
@@ -108,7 +108,7 @@ describe('<LibraryCollectionPage />', () => {
   it('shows an error component if no collection returned', async () => {
     // This mock will simulate incorrect collection id
     await renderLibraryCollectionPage(mockCollection.collectionEmpty);
-    expect(await screen.findByText(/Mocked request failed with status code 400./)).toBeInTheDocument();
+    expect(await screen.findByText(/Mocked request failed with status code 404./)).toBeInTheDocument();
   });
 
   it('shows collection data', async () => {

src/library-authoring/data/api.mocks.ts

@@ -281,13 +281,22 @@ mockLibraryBlockMetadata.applyMock = () => jest.spyOn(api, 'getLibraryBlockMetad
  * This mock returns a fixed response for the collection ID *collection_1*.
  */
 export async function mockGetCollectionMetadata(libraryId: string, collectionId: string): Promise<api.Collection> {
-  if (collectionId === mockGetCollectionMetadata.collectionIdError) {
-    throw createAxiosError({ code: 400, message: 'Not found.', path: api.getLibraryCollectionApiUrl(libraryId, collectionId) });
+  switch (collectionId) {
+    case mockGetCollectionMetadata.collectionIdError:
+      throw createAxiosError({
+        code: 404,
+        message: 'Not found.',
+        path: api.getLibraryCollectionApiUrl(libraryId, collectionId),
+      });
+    case mockGetCollectionMetadata.collectionIdLoading:
+      return new Promise(() => {});
+    default:
+      return Promise.resolve(mockGetCollectionMetadata.collectionData);
   }
-  return Promise.resolve(mockGetCollectionMetadata.collectionData);
 }
 mockGetCollectionMetadata.collectionId = 'collection_1';
 mockGetCollectionMetadata.collectionIdError = 'collection_error';
+mockGetCollectionMetadata.collectionIdLoading = 'collection_loading';
 mockGetCollectionMetadata.collectionData = {
   id: 1,
   key: 'collection_1',