Error: JavaScript Jupyter kernel not found

[laggingreflex]

Getting this error:

magicpatch-install
Error: JavaScript Jupyter kernel not found. Try installing or re-installing IJavascript?
at C:\Users...\AppData\Roaming\npm\node_modules\magicpatch\bin\magicPatchInstall.js:30:15
at processTicksAndRejections (node:internal/process/task_queues:96:5)

I believe I have IJavascript installed and working. I can run JS code in my notebook in VSCode by selecting Javascript Kernel.

I'm on Windows and have followed the Anaconda method https://github.com/n-riesco/ijavascript#windows-anaconda-distribution to install IJavascript.

I'm running magicpatch-install in an elevated Anaconda shell.

In the file magicPatchInstall.js:30 I logged jupyterConfig, kernels and got

{
  Jupyter: {
    packages: [
      { package: 'parsing error', version: 'parsing error' },
      [Object: null prototype] {
        package: 'IPython',
        version: '7.29.0'
      },
      [Object: null prototype] {
        package: 'ipykernel',
        version: '6.4.1'
      },
      ....
    ]
  }
}
kernels: [
  { kernel: 'parsing error', path: 'parsing error' },
  { kernel: 'parsing error', path: 'parsing error' }
]

Does this make it seem that I don't have IJavascript installed properly? But then how am I able to use it in VSCode..? And what could I do?

[laggingreflex]

Found the problem. This change in lib\magics\report\jupyter.js:54 makes it work:

// let match = line.match(/^\s+(?<kernel>\w+)\s+(?<path>\/.*)$/);
let match = line.match(/^\s+(?<kernel>\w+)\s+(?<path>[\w\/].*)/);

(apart from adding \w, removing $ was also required for reasons beyond me.)

The regex used was based on:

// 'jupyter kernelspec list' should look like:

// Available kernels:
//   javascript      /Users/ampower/Library/Jupyter/kernels/javascript
//   javascriptex    /Users/ampower/Library/Jupyter/kernels/javascriptex
//   python3         /opt/local/Library/Frameworks/Python.framework/Versions/3.7/share/jupyter/kernels/python3

However on my Windows it looks like

jupyter kernelspec list
Available kernels:
  javascript    C:\Users\me\AppData\Roaming\jupyter\kernels\javascript
  python3       C:\tools\Anaconda3\share\jupyter\kernels\python3

Please feel free to use this as a patch. I'm not confident in my Regex so I'd double check if it still works in *nix.

[apowers313]

Super helpful, thank you. I’ll try to incorporate the fix in the next release. Might be a few weeks as I’m working on a Deno kernel right now. :)