lite: Replace piplite override with minimal patch in robotkernel add-on

Author: datakurre

lite/jupyterlite-robotkernel/py_src/jupyterlite_robotkernel/__init__.py

@@ -1,4 +1,5 @@
 from ._version import __version__, __js__
 
+
 def _jupyter_labextension_paths():
-    return [{ "src": "labextension", "dest": __js__["name"]}]
+    return [{"src": "labextension", "dest": __js__["name"]}]

lite/jupyterlite-robotkernel/py_src/jupyterlite_robotkernel/addons/piplite.py

@@ -1,20 +1,30 @@
 """Install RobotKernel wheels."""
 from importlib import resources
 from jupyterlite.addons.base import BaseAddon
+from jupyterlite.constants import JUPYTERLITE_JSON
+from jupyterlite.constants import LITE_PLUGIN_SETTINGS
+from jupyterlite.constants import JUPYTER_CONFIG_DATA
+from jupyterlite.constants import UTF8
+from jupyterlite.constants import ALL_JSON
+from jupyterlite.constants import JSON_FMT
+from jupyterlite.addons.piplite import PYPI_WHEELS
+from jupyterlite.addons.piplite import PIPLITE_URLS
 from pathlib import Path
+from hashlib import sha256
 
 import json
 import traitlets
 
 DEFAULT_WHEELS = json.loads(
     resources.read_text("jupyterlite_robotkernel.addons", "wheels.json")
 )
+ROBOLITE_PLUGIN_ID = "@jupyterlite/robolite-kernel-extension:kernel"
 
 
 class RobotKernelAddon(BaseAddon):
     """Ensures the unique dependencies of robotkernel are available."""
 
-    __all__ = ["pre_build"]
+    __all__ = ["pre_build", "post_build"]
 
     wheel_urls = traitlets.List(DEFAULT_WHEELS).tag(config=True)
 
@@ -27,5 +37,61 @@ def pre_build(self, manager):
             yield dict(
                 name=f"""fetch:{wheel.rsplit("/", 1)[-1]}""",
                 actions=[(self.fetch_one, [wheel, dest])],
-                targets=[dest]
+                targets=[dest],
             )
+
+    def post_build(self, manager):
+        jupyterlite_json = manager.output_dir / JUPYTERLITE_JSON
+        whl_index = manager.output_dir / PYPI_WHEELS / ALL_JSON
+        yield dict(
+            name="patch",
+            doc=f"ensure {JUPYTERLITE_JSON} includes any piplite wheels",
+            file_dep=[jupyterlite_json, whl_index],
+            actions=[
+                (
+                    self.patch_jupyterlite_json,
+                    [jupyterlite_json, whl_index],
+                )
+            ],
+            targets=[f"{whl_index}#"],  # TODO: target
+        )
+
+    def patch_jupyterlite_json(self, jupyterlite_json, whl_index):
+        """add the piplite wheels to jupyter-lite.json"""
+        config = json.loads(jupyterlite_json.read_text(**UTF8))
+        old_urls = (
+            config.setdefault(JUPYTER_CONFIG_DATA, {})
+            .setdefault(LITE_PLUGIN_SETTINGS, {})
+            .setdefault(ROBOLITE_PLUGIN_ID, {})
+            .get(PIPLITE_URLS, [])
+        )
+
+        new_urls = []
+        whl_index_url, whl_index_url_with_sha = self.get_index_urls(whl_index)
+        added_build = False
+        for url in old_urls:
+            if url.split("#")[0].split("?")[0] == whl_index_url:
+                new_urls += [whl_index_url_with_sha]
+                added_build = True
+            else:
+                new_urls += [url]
+        if not added_build:
+            new_urls = [whl_index_url_with_sha, *new_urls]
+
+        # ... and only update if actually changed
+        if len(new_urls) > len(old_urls) or added_build:
+
+            config[JUPYTER_CONFIG_DATA][LITE_PLUGIN_SETTINGS][ROBOLITE_PLUGIN_ID][
+                PIPLITE_URLS
+            ] = new_urls
+
+            jupyterlite_json.write_text(json.dumps(config, **JSON_FMT), **UTF8)
+
+            self.maybe_timestamp(jupyterlite_json)
+
+    def get_index_urls(self, whl_index):
+        """get output dir relative URLs for all.json files"""
+        whl_index_sha256 = sha256(whl_index.read_bytes()).hexdigest()
+        whl_index_url = f"./{whl_index.relative_to(self.manager.output_dir).as_posix()}"
+        whl_index_url_with_sha = f"{whl_index_url}?sha256={whl_index_sha256}"
+        return whl_index_url, whl_index_url_with_sha

lite/jupyterlite-robotkernel/py_src/jupyterlite_robotkernel/addons/robotkernel.py

@@ -52,5 +52,4 @@ where =
 
 [options.entry_points]
 jupyterlite.addon.v0 =
-    piplite = jupyterlite_robotkernel.addons.piplite:PipliteAddon
     robotkernel = jupyterlite_robotkernel.addons.robotkernel:RobotKernelAddon