Add helper functions to export all loaded annotations

src/shared/export-json-file.ts

@@ -0,0 +1,29 @@
+/**
+ * Provided an object and a filename, allows to generate a downloadable file
+ * containing a JSON-serialized version of that object
+ *
+ * @param _document - Test seam
+ * @return The contents of the downloaded file
+ */
+export function exportJSONFile(
+  exportData: object,
+  filename: string,
+  _document = document
+): string {
+  const link = _document.createElement('a');
+  const fileContent = JSON.stringify(exportData, null, 2);
+  const blob = new Blob([fileContent], {
+    type: 'application/json',
+  });
+  const url = URL.createObjectURL(blob);
+
+  link.setAttribute('href', url);
+  link.setAttribute('download', filename);
+  link.style.visibility = 'hidden';
+
+  _document.body.appendChild(link);
+  link.click();
+  _document.body.removeChild(link);
+
+  return fileContent;
+}

src/shared/test/export-json-file-test.js

@@ -0,0 +1,43 @@
+import { exportJSONFile } from '../export-json-file';
+
+describe('export-json-file', () => {
+  let fakeLink;
+  let fakeDocument;
+
+  beforeEach(() => {
+    fakeLink = {
+      setAttribute: sinon.stub(),
+      click: sinon.stub(),
+      style: {},
+    };
+
+    fakeDocument = {
+      createElement: sinon.stub().returns(fakeLink),
+      body: {
+        appendChild: sinon.stub(),
+        removeChild: sinon.stub(),
+      },
+    };
+  });
+
+  it('generates export file with provided annotations', () => {
+    const filename = 'my-file.json';
+    const data = { foo: ['bar', 'baz'] };
+
+    const fileContent = exportJSONFile(data, filename, fakeDocument);
+
+    assert.equal(fileContent, JSON.stringify(data, null, 2));
+
+    assert.calledWith(fakeDocument.createElement, 'a');
+    assert.calledWith(fakeDocument.body.appendChild, fakeLink);
+    assert.calledWith(fakeDocument.body.removeChild, fakeLink);
+
+    assert.calledWith(
+      fakeLink.setAttribute.firstCall,
+      'href',
+      sinon.match.string
+    );
+    assert.calledWith(fakeLink.setAttribute.secondCall, 'download', filename);
+    assert.equal('hidden', fakeLink.style.visibility);
+  });
+});

src/sidebar/helpers/export-annotations.ts

@@ -0,0 +1,31 @@
+import type { Annotation } from '../../types/api';
+
+export type ExportAnnotationsData = {
+  annotations: Annotation[];
+  clientVersion: string;
+  userId: string;
+};
+
+export type ExportContent = {
+  export_date: string;
+  export_userid: string;
+  client_version: string;
+  annotations: Annotation[];
+};
+
+/**
+ * @param now - Test seam
+ */
+export function buildExportFileContent(
+  { annotations, clientVersion, userId }: ExportAnnotationsData,
+  now = new Date()
+): ExportContent {
+  return {
+    export_date: now.toISOString(),
+    export_userid: userId,
+    client_version: clientVersion,
+
+    // TODO clean-up annotations, removing attributes generated by the client
+    annotations,
+  };
+}

src/sidebar/helpers/test/export-annotations-test.js

@@ -0,0 +1,20 @@
+import { buildExportFileContent } from '../export-annotations';
+
+describe('export-annotations', () => {
+  it('generates export content with provided annotations', () => {
+    const now = new Date();
+    const annotations = [{}, {}];
+
+    const result = buildExportFileContent(
+      { annotations, clientVersion: '1.0.0', userId: 'userId' },
+      now
+    );
+
+    assert.deepEqual(result, {
+      export_date: now.toISOString(),
+      export_userid: 'userId',
+      client_version: '1.0.0',
+      annotations,
+    });
+  });
+});