feat: Add WASM example with JupyterLite

[wolfv]

cc @ruben-arts

[ruben-arts]

Looks good, small changes. But it doesn't work on windows.

~\development\pixi\examples\wasm-jupyterlite git:[wasm]
pixi run serve
Pixi task (setup_wasm in default): pixi install -e wasm
The wasm environment has been installed.

Pixi task (build in default): jupyter lite build --XeusAddon.prefix=.pixi/envs/wasm --contents=./notebooks
static:jupyter-lite.json
.  pre_status:static:jupyter-lite.json
    tarball:         jupyterlite-app-0.3.0.tgz 13MB
    output:          C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\_output
    lite dir:        C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite
    apps:            
    sourcemaps:      True
    unused packages: True
archive:archive
contents:contents
icons:icons
lite:jupyter-lite.json
mimetypes:jupyter-lite.json
serve:contents
settings:overrides
translation:translation
.  status:archive:archive
[LiteBuildApp] No archive (yet): wasm-jupyterlite-jupyterlite.tgz
.  status:contents:contents
    contents: 1 files
.  status:icons:icons
    favicon files: 0 files
.  status:lite:jupyter-lite.json
[LiteBuildApp]     jupyter-lite.(json|ipynb): 0 files
.  status:mimetypes:jupyter-lite.json
    filetypes:         26
.  status:serve:contents
    url: http://127.0.0.1:8000/
    server: stdlib
    headers:
.  status:settings:overrides
    overrides.json: 0
.  status:translation:translation
    translation files: 0 files
static:output_dir
.  pre_init:static:output_dir
static:unpack
.  init:static:unpack
C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\jupyterlite_core\addons\base.py:294: UserWarning: install libarchive-c for better performance when working with archives: No module named 'libarchive'
  return has_optional_dependency(
federated_extensions:copy:ext:@jupyterlite/xeus
.  pre_build:federated_extensions:copy:ext:@jupyterlite/xeus
contents:copy:matplotlib.ipynb
C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\jupyterlite_core\addons\icons.py:43: UserWarning: [lite] [icons] install `jupyter_server` to copy notebook favicons: No module named 'jupyter_server'
  if not self.is_sys_prefix_ignored() and has_optional_dependency(
C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\jupyterlite_core\addons\translation.py:88: UserWarning: [lite] [translation] install `jupyterlab_server` to load translations: No module named 'jupyterlab_server'
  if not self.is_sys_prefix_ignored() and has_optional_dependency(
translation:copy
.  build:contents:copy:matplotlib.ipynb
.  build:translation:copy
contents:contents:.
federated_extensions:patch
federated_extensions:settings
[LiteBuildApp] ERROR | [lite] [post_build] [jupyterlite-xeus] [ERR] Invalid \escape: line 4 column 10 (char 66)
Traceback (most recent call last):
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\doit\doit_cmd.py", line 294, in run
    return command.parse_execute(args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\doit\cmd_base.py", line 150, in parse_execute
    return self.execute(params, args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\doit\cmd_base.py", line 570, in execute
    return self._execute(**exec_params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\doit\cmd_run.py", line 265, in _execute
    return runner.run_all(self.control.task_dispatcher())
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\doit\runner.py", line 254, in run_all
    self.run_tasks(task_dispatcher)
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\doit\runner.py", line 213, in run_tasks
    node = task_dispatcher.generator.send(node)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\doit\control.py", line 629, in _dispatcher_generator
    next_step = node.step()
                ^^^^^^^^^^^
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\doit\control.py", line 336, in step
    return next(self.generator)
           ^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\doit\control.py", line 345, in _func
    for value in decorated(*args, **kwargs):
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\doit\control.py", line 473, in _add_task
    new_tasks = generate_tasks(to_load, task_gen, ref.__doc__)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\doit\loader.py", line 390, in generate_tasks
    for task_dict, x_doc in flat_generator(gen_result, gen_doc):
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\doit\loader.py", line 27, in flat_generator
    for item in gen:
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\jupyterlite_core\manager.py", line 138, in _delayed_gather
    yield from _gather()
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\jupyterlite_core\manager.py", line 131, in _gather
    raise error
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\jupyterlite_core\manager.py", line 123, in _gather
    for task in getattr(addon, attr)(self):
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\jupyterlite_xeus\add_on.py", line 127, in post_build
    yield from self.copy_kernels_from_prefix()
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\jupyterlite_xeus\add_on.py", line 174, in copy_kernels_from_prefix
    kernel_binaries = get_kernel_binaries(kernel_dir)
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\site-packages\jupyterlite_xeus\add_on.py", line 46, in get_kernel_binaries
    kernel_spec = json.loads(json_file.read_text(**UTF8))
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\json\__init__.py", line 346, in loads
    return _default_decoder.decode(s)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\json\decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Ruben\development\pixi\examples\wasm-jupyterlite\.pixi\envs\default\Lib\json\decoder.py", line 353, in raw_decode
    obj, end = self.scan_once(s, idx)
               ^^^^^^^^^^^^^^^^^^^^^^
json.decoder.JSONDecodeError: Invalid \escape: line 4 column 10 (char 66)

[jtpio]

Looks like the contents CLI flag may be missing to pick up the content?

Suggested change

	cmd = "jupyter lite build --XeusAddon.prefix=.pixi/envs/wasm"
	cmd = "jupyter lite build --XeusAddon.prefix=.pixi/envs/wasm --contents files"

[wolfv]

I moved the file to the ./files folder and it's picked up correctly.

However, I had to add jupyter_server to the host environment to make things work :)

[jtpio]

ah ok. Yes jupyter_server is indeed needed to index the contents.

Otherwise maybe you could keep just the notebooks folder and provide --contents notebooks.

[wolfv]

@ruben-arts I fixed the conflicts from before. I think this is good now :)

[baszalmstra]

This doesnt seem to work on my (windows) machine because:

× failed to fetch contourpy-1.2.1-np125py311hd4e2776_0.tar.bz2
  ├─▶ an io error occurred
  ├─▶ failed to unpack `\\?\F:\packages\pixi\pkgs\contourpy-1.2.1-np125py311hd4e2776_0\bin\python.bak`
  ╰─▶ A required privilege is not held by the client. (os error 1314) when symlinking python3.11 to \\?\F:
      \packages\pixi\pkgs\contourpy-1.2.1-np125py311hd4e2776_0\bin\python.bak

Most likely one of the packages uses a symlink.

[ruben-arts]

LGTM