Specify needed shared libs in wasm kernel spec

[anutosh491]

Fixes #219

Built on top of #220 and should be rebased once that goes in

[anutosh491]

Quite some things won't be required for the wasm kernel as mentioned here (#185)

I shall make the changes in wasm_kernel.json.in once I confirm the requirement for the variables. Converting to draft till then.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.03%. Comparing base (a643ea4) to head (b9db408).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #221      +/-   ##
==========================================
+ Coverage   80.72%   81.03%   +0.30%     
==========================================
  Files          19       19              
  Lines         970      970              
  Branches       93       93              
==========================================
+ Hits          783      786       +3     
+ Misses        187      184       -3     

see 1 file with indirect coverage changes

see 1 file with indirect coverage changes

[anutosh491]

As compared to the native kernel, the wasm kernel spec won't be having

1. The env field

  "env": {
      "PATH":"@XEUS_CPP_PATH@",
      "LD_LIBRARY_PATH":"@XEUS_CPP_LD_LIBRARY_PATH@"
  }
  

This is because even if we want to access an environment variables i.e. our wasm module needs something, it needs to end up in our js file (xcpp.js) before the wasm module is initialized and that is done through a pre.js file and not this way. See the following to see how xeus-r injects env variables to make use of it (jupyter-xeus/xeus-r@6344e4d)

2. The resource dir

"-resource-dir", "@XEUS_CPP_RESOURCE_DIR@"

This is because, we can't use resource dir this way through a flag. For accessing the resource dir, first we want CppInterOp to provide a resource dir that needs to be preloaded along side the sysroot using --preload-file.

3. The include dir

"-I", "@XEUS_CPP_INCLUDE_DIR@",

Again we can't access a local path like this /Users/anutosh491/micromamba/envs/xeus-cpp-wasm-host through a flag. xeus-cpp-wasm-host is basically the environment we are interested in. And accessing stuff out of this environment would anyways be done by Jupyterlite-xeus leveraging empack

After running jupyter lite build, we can see the _output directory would fetch all the required kernel packages (the tar.gz files) and create an empack_env_meta.json (looks like this for me locally)

{
    "prefix": "/",
    "packages": [
        {
            "name": "emscripten-abi",
            "version": "3.1.45",
            "build": "h267e887_32",
            "filename_stem": "emscripten-abi-3.1.45-h267e887_32",
            "filename": "emscripten-abi-3.1.45-h267e887_32.tar.gz"
        },
        {
            "name": "xeus-lite",
            "version": "3.0.0",
            "build": "h5ef0a50_1",
            "filename_stem": "xeus-lite-3.0.0-h5ef0a50_1",
            "filename": "xeus-lite-3.0.0-h5ef0a50_1.tar.gz"
        },
       .........
       ........
        {
            "name": "cppinterop",
            "version": "1.5.0",
            "build": "h18da88b_2",
            "filename_stem": "cppinterop-1.5.0-h18da88b_2",
            "filename": "cppinterop-1.5.0-h18da88b_2.tar.gz"
        },
        {
            "name": "nlohmann_json",
            "version": "3.11.3",
            "build": "he2bab0f_1",
            "filename_stem": "nlohmann_json-3.11.3-he2bab0f_1",
            "filename": "nlohmann_json-3.11.3-he2bab0f_1.tar.gz"
        }
    ]
}

This basically leads to unpacking contents from these packages in the browser before we create the interpreter.

[martinRenou]

LGTM! Just a small question

[martinRenou]

👌🏽

[martinRenou]

Is notebook really required?

[anutosh491]

Not really but I think was added earlier by a contributor as an alternative to lab, hence the change is present there. Keeping it for now and can be removed subsequently if not adding value.

[martinRenou]

as an alternative to lab

Installing notebook will have no impact on this concerning JupyterLite.

It's the jupyter lite build --apps notebook --apps lab which impacts which kinds of UIs are installed.

JupyterLite already defaults to providing the notebook UI actually, you'll only need to point to a different URL. e.g. for xeus-r you can go on https://jupyter-xeus.github.io/xeus-r/tree instead of https://jupyter-xeus.github.io/xeus-r/lab

[anutosh491]

Ohh okay wow, I didn't know we could frame the url like this. Getting rid of it !

[martinRenou]

Happy to see this being removed :D

[anutosh491]

Thanks for the reviews. Merging !