Native Notebooks - Cell output is rendered twice

[KiruyaMomochi]

Environment data

• VS Code version:

  Version: 1.53.0-insider (user setup)
  Commit: 76436a4d43566cd313629799e2ec51b4d00caa64
  Date: 2020-12-11T17:56:17.606Z
  Electron: 11.0.3
  Chrome: 87.0.4280.67
  Node.js: 12.18.3
  V8: 8.7.220.25-electron.0
  OS: Windows_NT x64 10.0.20277

• Jupyter Extension version (available under the Extensions sidebar): 2020.12.414227025
• Python Extension version (available under the Extensions sidebar): 2020.11.371526539, with Pylance 2020.12.2
• OS (Windows | Mac | Linux distro) and version: Microsoft Windows 10.0.20277
• Python and/or Anaconda version: Python 3.9.0 (tags/v3.9.0:9cf6752, Oct 5 2020, 15:34:40) [MSC v.1927 64 bit (AMD64)]
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): N/A
• Jupyter server running: Local

Expected behaviour

The desired output is printed only once.

Actual behaviour

The desired output is printed twice (double/duplicated output).

Steps to reproduce

1. Open Command Pattle, run command Jupyter: Create New Blank Jupyter Notebook.
2. After the new notebook is opened, type something like 123 then press Shift + Enter. (Make sure you're using Native Notebook Editor)
3. You can see the output is 123123, which should be 123 only.

Logs

Output for Jupyter in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Jupyter)

```log 使用者屬於 "NativeNotebookEditor" 實驗性群組 (TRANSLATE: User is in the "NativeNotebookEditor" expermential group) > c:\Users\xtyzw\Projects\d2l\d2l\Scripts\python.exe c:\Users\xtyzw\.vscode-insiders\extensions\ms-toolsai.jupyter-2020.12.414227025\pythonFiles\pyvsc-run-isolated.py -c "import notebook" > c:\Users\xtyzw\Projects\d2l\d2l\Scripts\python.exe c:\Users\xtyzw\.vscode-insiders\extensions\ms-toolsai.jupyter-2020.12.414227025\pythonFiles\pyvsc-run-isolated.py -c "import jupyter" > c:\Users\xtyzw\Projects\d2l\d2l\Scripts\python.exe c:\Users\xtyzw\.vscode-insiders\extensions\ms-toolsai.jupyter-2020.12.414227025\pythonFiles\pyvsc-run-isolated.py jupyter kernelspec --version > c:\Users\xtyzw\Projects\d2l\d2l\Scripts\python.exe c:\Users\xtyzw\.vscode-insiders\extensions\ms-toolsai.jupyter-2020.12.414227025\pythonFiles\pyvsc-run-isolated.py vscode_datascience_helpers.daemon --daemon-module=vscode_datascience_helpers.jupyter_daemon -v > c:\Users\xtyzw\Projects\d2l\d2l\Scripts\python.exe c:\Users\xtyzw\.vscode-insiders\extensions\ms-toolsai.jupyter-2020.12.414227025\pythonFiles\pyvsc-run-isolated.py vscode_datascience_helpers.daemon --daemon-module=vscode_datascience_helpers.jupyter_daemon -v > c:\Users\xtyzw\Projects\d2l\d2l\Scripts\python.exe c:\Users\xtyzw\.vscode-insiders\extensions\ms-toolsai.jupyter-2020.12.414227025\pythonFiles\pyvsc-run-isolated.py vscode_datascience_helpers.daemon --daemon-module=vscode_datascience_helpers.jupyter_daemon -v > dotnet interactive jupyter --default-kernel powershell ~\AppData\Local\Temp\tmp-1856zTmtrY8hNK7u.json cwd: ~\AppData\Local\Programs\Microsoft VS Code Insiders Started kernel .NET (PowerShell) > dotnet interactive jupyter --default-kernel powershell ~\AppData\Local\Temp\tmp-1856sFWXll6dB1I9.json cwd: ~\AppData\Local\Programs\Microsoft VS Code Insiders Error 2020-12-12 13:33:53: Jupyter Kernel Spec not found for a local connection > ~\AppData\Local\Microsoft\WindowsApps\python.exe c:\Users\xtyzw\.vscode-insiders\extensions\ms-toolsai.jupyter-2020.12.414227025\pythonFiles\pyvsc-run-isolated.py vscode_datascience_helpers.daemon --daemon-module=vscode_datascience_helpers.kernel_launcher_daemon -v > ~\AppData\Local\Microsoft\WindowsApps\python.exe c:\Users\xtyzw\.vscode-insiders\extensions\ms-toolsai.jupyter-2020.12.414227025\pythonFiles\pyvsc-run-isolated.py vscode_datascience_helpers.daemon --daemon-module=vscode_datascience_helpers.kernel_launcher_daemon -v Started kernel Python 3.9.0 64-bit > ~\AppData\Local\Microsoft\WindowsApps\python.exe c:\Users\xtyzw\.vscode-insiders\extensions\ms-toolsai.jupyter-2020.12.414227025\pythonFiles\pyvsc-run-isolated.py vscode_datascience_helpers.daemon --daemon-module=vscode_datascience_helpers.kernel_launcher_daemon -v > ~\AppData\Local\Microsoft\WindowsApps\python.exe c:\Users\xtyzw\.vscode-insiders\extensions\ms-toolsai.jupyter-2020.12.414227025\pythonFiles\pyvsc-run-isolated.py vscode_datascience_helpers.daemon --daemon-module=vscode_datascience_helpers.kernel_launcher_daemon -v ```

Additional Information

• The problem occurs in kernel Python, .NET (PowerShell), but not in .NET (C#). By inspecting the raw json file, you can see the reason is this problem only exists for type text/plain - and that's true, change it to text/html then output only prints once.

  `Python` cell raw output

  ```json "outputs": [ { "data": { "text/plain": "123" }, "execution_count": 1, "metadata": {}, "output_type": "execute_result" } ], ```

  `C#` cell raw output

  ```json "outputs": [ { "data": { "text/html": "" }, "metadata": { "transient": { "display_id": "4b284a09-c6d1-4cce-ad12-8d2b03d59d0c" } }, "output_type": "display_data" }, { "data": { "text/html": "123" }, "execution_count": 1, "metadata": { "transient": { "display_id": "0cf11c49-79dd-44de-b5a7-5d205967941c" } }, "output_type": "execute_result" } ], ```

• The problem doesn't exists in either traditional notebook experience or jupyter webpage.
• If you open the ipynb file with a text editor, you can see the output only once.
• If you use developer tools to inspect the output, you can see the redundant output is in a span tag.

  <div class="output-plaintext">
    123
    <span><span class="">123</span></span>
  </div>

• The issue may releated to https://github.com/microsoft/vscode-jupyter/issues/635.

[arsdragonfly]

can confirm

[DavidKutu]

Thank you for the issue @KiruyaMomochi. I've been trying, but I'm not able to reproduce your issue:

Is it consistent for you? Or does it happen only sometimes?

[KiruyaMomochi]

@DavidKutu

Yes it's consistent for me. I can reproduce the issue now, following the provided steps.

[DavidKutu]

@KiruyaMomochi, another dev from the team can also repro consistently. We'll follow the issue on the vscode repo. In the mean time you could use stable if possible.

[KiruyaMomochi]

Fixed.

[gvanrossum]

Where did you get this version of the extension that doesn't double the output? I still see it, and I'm on VS Code insiders and Jupyter insiders daily (v2020.12.414227025).

[DavidKutu]

Hey Guido, what is your VS Code insiders version? Is it 1.53?

[gvanrossum]

It is, but I just checked for updates and found one, and now things are fixed. So sorry! Should have thought of that before (this is not the first time that happened... :-( )