Fix handling of channels from prefixes

Author: martinRenou

jupyterlite_xeus/add_on.py

@@ -158,8 +158,6 @@ def post_build(self, manager):
                     raise ValueError(f"Environment name '{env_name}' used more than once")
                 self.prefixes[env_name] = prefix
                 self.specs[env_name] = self.get_environment_specs(prefix)
-                # For lack of a better way for now
-                self.channels[env_name] = DEFAULT_CHANNELS
 
         all_kernels = []
         for env_name, prefix in self.prefixes.items():
@@ -357,7 +355,7 @@ def copy_kernel(self, env_name, prefix, kernel_dir, kernel_wasm, kernel_js, kern
             ],
         )
 
-    def update_empack_meta(self, file_path, new_data):
+    def update_empack_meta(self, file_path, env_name, new_data):
         if file_path.exists():
             with open(file_path, "r", encoding="utf-8") as f:
                 data = json.load(f)
@@ -366,6 +364,18 @@ def update_empack_meta(self, file_path, new_data):
 
         data.update(new_data)
 
+        # TODO Channel priority????
+        # Generate channels entry
+        if not hasattr(self.channels, env_name):
+            # Detect channels from empack_meta
+            self.channels[env_name] = []
+            for pkg in data["packages"]:
+                pkg_channel = pkg.get("channel", None)
+                if pkg_channel is not None and pkg_channel != 'PyPi' and pkg_channel not in self.channels[env_name]:
+                    self.channels[env_name].append(pkg_channel)
+
+        data.update({"channels": self.channels[env_name]})
+
         with open(file_path, "w", encoding="utf-8") as f:
             json.dump(data, f, indent=2)
 
@@ -488,7 +498,8 @@ def pack_prefix(self, env_name, prefix):
                     self.update_empack_meta,
                     [
                         out_path / EMPACK_ENV_META,
-                        {"specs": self.specs[env_name], "channels": self.channels[env_name]},
+                        env_name,
+                        {"specs": self.specs[env_name]},
                     ],
                 ),
                 (

tests/test_xeus.py

@@ -210,8 +210,6 @@ def test_multiple_envs():
         update_action_args = update_cp_env_steps["actions"][0][1]
         expected_tmp_path = update_action_args[0]
         assert expected_tmp_path.name == "empack_env_meta.json"
-        assert isinstance(update_action_args[1], dict)
-        assert "specs" in update_action_args[1]
 
         copy_action_args = update_cp_env_steps["actions"][1][1]
         assert copy_action_args[1] == target_path / env_name_tmp / "empack_env_meta.json"