Extract local html detection logic to separate function and use the `…

…urllib.parse` module

extensions/positron-python/python_files/positron/positron_ipykernel/ui.py

@@ -23,7 +23,7 @@
     UiFrontendEvent,
     WorkingDirectoryParams,
 )
-from .utils import JsonData, JsonRecord, alias_home
+from .utils import JsonData, JsonRecord, alias_home, is_local_html_file
 
 logger = logging.getLogger(__name__)
 
@@ -179,9 +179,8 @@ def open(self, url, new=0, autoraise=True):
         if not self._comm:
             return False
 
-        # Check if the url starts with 'file://', and if it does send the comm message
-        # for opening an html file and ends with '.html' or '.htm' to open the file in the browser
-        if url.startswith("file://") and (url.endswith(".html") or url.endswith(".htm")):
+        # If url is pointing to an HTML file, route to the ShowHtmlFile comm
+        if is_local_html_file(url):
             self._comm.send_event(
                 name=UiFrontendEvent.ShowHtmlFile,
                 payload={

extensions/positron-python/python_files/positron/positron_ipykernel/utils.py

@@ -25,6 +25,7 @@
     Union,
     cast,
 )
+from urllib.parse import urlparse, unquote
 
 JsonData = Union[Dict[str, "JsonData"], List["JsonData"], str, int, float, bool, None]
 JsonRecord = Dict[str, JsonData]
@@ -384,3 +385,23 @@ def positron_ipykernel_usage():
     "numpy.cdouble",
     "numpy.clongdouble",
 ]
+
+
+def is_local_html_file(url: str) -> bool:
+    """Check if a URL points to a local HTML file."""
+    try:
+        parsed_url = urlparse(unquote(url))
+
+        # Check if it's a file scheme
+        if parsed_url.scheme not in ("file"):
+            return False
+
+        # Check if the path contains the .html or .htm extensions
+        path = parsed_url.path.lower()
+        if any(ext in path for ext in (".html", ".htm")):
+            return True
+
+        return False
+
+    except Exception:
+        return False