Render error toast message if an error occurs when exporting annotations

src/sidebar/components/ShareDialog/ExportAnnotations.tsx

@@ -4,6 +4,7 @@ import { useRef } from 'preact/hooks';
 import { downloadJSONFile } from '../../../shared/download-json-file';
 import { withServices } from '../../service-context';
 import type { AnnotationsExporter } from '../../services/annotations-exporter';
+import type { ToastMessengerService } from '../../services/toast-messenger';
 import { useSidebarStore } from '../../store';
 import { suggestedFilename } from '../../util/export-annotations';
 import LoadingSpinner from './LoadingSpinner';
@@ -11,6 +12,7 @@ import LoadingSpinner from './LoadingSpinner';
 export type ExportAnnotationsProps = {
   // injected
   annotationsExporter: AnnotationsExporter;
+  toastMessenger: ToastMessengerService;
 };
 
 // TODO: Validate user-entered filename
@@ -20,7 +22,10 @@ export type ExportAnnotationsProps = {
  * Render content for "export" tab panel: allow user to export annotations
  * with a specified filename.
  */
-function ExportAnnotations({ annotationsExporter }: ExportAnnotationsProps) {
+function ExportAnnotations({
+  annotationsExporter,
+  toastMessenger,
+}: ExportAnnotationsProps) {
   const store = useSidebarStore();
   const group = store.focusedGroup();
   const exportReady = group && !store.isLoading();
@@ -35,11 +40,15 @@ function ExportAnnotations({ annotationsExporter }: ExportAnnotationsProps) {
   }
 
   const exportAnnotations = () => {
-    const filename = `${inputRef.current!.value}.json`;
-    const exportData = annotationsExporter.buildExportContent(
-      exportableAnnotations,
-    );
-    downloadJSONFile(exportData, filename);
+    try {
+      const filename = `${inputRef.current!.value}.json`;
+      const exportData = annotationsExporter.buildExportContent(
+        exportableAnnotations,
+      );
+      downloadJSONFile(exportData, filename);
+    } catch (e) {
+      toastMessenger.error('Exporting annotations failed');
+    }
   };
 
   // Naive simple English pluralization
@@ -90,4 +99,7 @@ function ExportAnnotations({ annotationsExporter }: ExportAnnotationsProps) {
   );
 }
 
-export default withServices(ExportAnnotations, ['annotationsExporter']);
+export default withServices(ExportAnnotations, [
+  'annotationsExporter',
+  'toastMessenger',
+]);

src/sidebar/components/ShareDialog/test/ExportAnnotations-test.js

@@ -8,6 +8,7 @@ import ExportAnnotations, { $imports } from '../ExportAnnotations';
 describe('ExportAnnotations', () => {
   let fakeStore;
   let fakeAnnotationsExporter;
+  let fakeToastMessenger;
   let fakeDownloadJSONFile;
 
   const fakePrivateGroup = {
@@ -20,6 +21,7 @@ describe('ExportAnnotations', () => {
     mount(
       <ExportAnnotations
         annotationsExporter={fakeAnnotationsExporter}
+        toastMessenger={fakeToastMessenger}
         {...props}
       />,
     );
@@ -28,6 +30,9 @@ describe('ExportAnnotations', () => {
     fakeAnnotationsExporter = {
       buildExportContent: sinon.stub().returns({}),
     };
+    fakeToastMessenger = {
+      error: sinon.stub(),
+    };
     fakeDownloadJSONFile = sinon.stub();
     fakeStore = {
       countDrafts: sinon.stub().returns(0),
@@ -107,6 +112,9 @@ describe('ExportAnnotations', () => {
   });
 
   describe('export button clicked', () => {
+    const clickExportButton = wrapper =>
+      wrapper.find('button[data-testid="export-button"]').simulate('click');
+
     it('builds an export file from the non-draft annotations', () => {
       const wrapper = createComponent();
       const annotationsToExport = [
@@ -115,13 +123,14 @@ describe('ExportAnnotations', () => {
       ];
       fakeStore.savedAnnotations.returns(annotationsToExport);
 
-      wrapper.find('button[data-testid="export-button"]').simulate('click');
+      clickExportButton(wrapper);
 
       assert.calledOnce(fakeAnnotationsExporter.buildExportContent);
       assert.calledWith(
         fakeAnnotationsExporter.buildExportContent,
         annotationsToExport,
       );
+      assert.notCalled(fakeToastMessenger.error);
     });
 
     it('downloads a file using user-entered filename appended with `.json`', () => {
@@ -130,7 +139,7 @@ describe('ExportAnnotations', () => {
       wrapper.find('input[data-testid="export-filename"]').getDOMNode().value =
         'my-filename';
 
-      wrapper.find('button[data-testid="export-button"]').simulate('click');
+      clickExportButton(wrapper);
 
       assert.calledOnce(fakeDownloadJSONFile);
       assert.calledWith(
@@ -139,6 +148,25 @@ describe('ExportAnnotations', () => {
         'my-filename.json',
       );
     });
+
+    context('when exporting annotations fails', () => {
+      it('displays error toast message', () => {
+        fakeAnnotationsExporter.buildExportContent.throws(
+          new Error('Error exporting'),
+        );
+
+        const wrapper = createComponent();
+
+        clickExportButton(wrapper);
+
+        assert.notCalled(fakeDownloadJSONFile);
+        assert.calledOnce(fakeAnnotationsExporter.buildExportContent);
+        assert.calledWith(
+          fakeToastMessenger.error,
+          'Exporting annotations failed',
+        );
+      });
+    });
   });
 
   context('no annotations available to export', () => {