Purge sharing-specific metadata before downloading notebooks as IPyNB files (#238)

Author: agriyakhetarpal

src/index.ts

@@ -192,7 +192,37 @@ const plugin: JupyterFrontEndPlugin<void> = {
     commands.addCommand(Commands.downloadNotebookCommand, {
       label: 'Download as a notebook',
       execute: args => {
-        // Execute the built-in download command
+        // Clear all sharing-specific metadata before download
+        const panel = readonlyTracker.currentWidget ?? tracker.currentWidget;
+
+        if (!panel) {
+          console.warn('No active notebook to download');
+          return;
+        }
+
+        const content = panel.context.model.toJSON() as INotebookContent;
+
+        // Remove sharing-specific metadata
+        const purgedMetadata = { ...content.metadata };
+        delete purgedMetadata.isSharedNotebook;
+        delete purgedMetadata.sharedId;
+        delete purgedMetadata.readableId;
+        delete purgedMetadata.sharedName;
+        delete purgedMetadata.lastShared;
+
+        // Ensure that we preserve kernelspec metadata if present
+        const kernelSpec = content.metadata?.kernelspec;
+        if (kernelSpec) {
+          purgedMetadata.kernelspec = kernelSpec;
+        }
+
+        const cleanedContent: INotebookContent = {
+          ...content,
+          metadata: purgedMetadata
+        };
+        panel.context.model.fromJSON(cleanedContent);
+
+        // Execute the built-in download command with the cleaned model
         return commands.execute('docmanager:download');
       }
     });
@@ -427,7 +457,7 @@ const plugin: JupyterFrontEndPlugin<void> = {
           delete purgedMetadata.sharedName;
           delete purgedMetadata.lastShared;
 
-          // Ensure that we preserve kernelspec metadata
+          // Ensure that we preserve kernelspec metadata if present
           const kernelSpec = originalContent.metadata?.kernelspec;
 
           // Remove cell-level editable=false; as the notebook has

ui-tests/tests/jupytereverywhere.spec.ts

@@ -33,7 +33,12 @@ const PYTHON_TEST_NOTEBOOK: JSONObject = {
       execution_count: null,
       id: '55eb9a2d-401d-4abd-b0eb-373ded5b408d',
       outputs: [],
-      metadata: {},
+      metadata: {
+        sharedId: 'some-random-alphanumeric-id',
+        readableId: 'python-test-notebook',
+        sharedName: 'Notebook_1980-10-30_00-10-20',
+        lastShared: '2024-06-20T00:10:20.123Z'
+      },
       source: [`# This is a test notebook`]
     }
   ],
@@ -316,6 +321,28 @@ test.describe('Download', () => {
     const pdfPath = await (await pdfDownload).path();
     expect(pdfPath).not.toBeNull();
   });
+
+  test('Notebook downloaded as IPyNB should not have sharing-specific metadata', async ({
+    page,
+    context
+  }) => {
+    await mockTokenRoute(page);
+    await mockShareNotebookResponse(page, 'test-download-metadata-notebook');
+
+    const ipynbDownload = page.waitForEvent('download');
+    await runCommand(page, 'jupytereverywhere:download-notebook');
+    const ipynbPath = await (await ipynbDownload).path();
+    expect(ipynbPath).not.toBeNull();
+
+    const content = await fs.promises.readFile(ipynbPath!, { encoding: 'utf-8' });
+    const notebook = JSON.parse(content) as JSONObject;
+    const metadata = notebook['metadata'] as JSONObject | undefined;
+    expect(metadata).toBeDefined();
+    expect(metadata).not.toHaveProperty('sharedId');
+    expect(metadata).not.toHaveProperty('readableId');
+    expect(metadata).not.toHaveProperty('sharedName');
+    expect(metadata).not.toHaveProperty('lastShared');
+  });
 });
 
 // We take a screenshot of the full files page, to