fix(annotations): update url for prefix (#2099)

* route back to url prefix instead of '/'

Author: mickr

src/elements/content-sidebar/Sidebar.js

@@ -135,7 +135,7 @@ class Sidebar extends React.Component<Props, State> {
     handleAnnotationSelect = (annotationId: string | null): void => {
         const { history } = this.props;
         const urlPrefix = this.getUrlPrefix(history.location.pathname);
-        const annotationUrl = annotationId ? `/${urlPrefix}/annotations/${annotationId}` : '/';
+        const annotationUrl = annotationId ? `/${urlPrefix}/annotations/${annotationId}` : `/${urlPrefix}`;
 
         history.push(annotationUrl);
     };

src/elements/content-sidebar/__tests__/Sidebar.test.js

@@ -148,7 +148,7 @@ describe('elements/content-sidebar/Sidebar', () => {
             expect(historyMock.push).toHaveBeenCalledWith('/activity/annotations/123');
         });
 
-        test('should handle setting url back to / if no id provided', () => {
+        test('should handle setting url back to url prefix if no id provided', () => {
             const historyMock = {
                 push: jest.fn(),
                 location: {
@@ -161,7 +161,7 @@ describe('elements/content-sidebar/Sidebar', () => {
 
             instance.handleAnnotationSelect(null);
 
-            expect(historyMock.push).toHaveBeenCalledWith('/');
+            expect(historyMock.push).toHaveBeenCalledWith('/activity');
         });
     });