Merge pull request #47701 from kshitijk4poor/salvage/cli-completer-keystroke-latency

fix(cli): keep typing responsive by running completion off the UI event loop

cli.py

@@ -12024,6 +12024,7 @@ class HermesCLI(CLIAgentSetupMixin, CLICommandsMixin):
 
         # Create the input area with multiline (Alt+Enter), autocomplete, and paste handling
         from prompt_toolkit.auto_suggest import AutoSuggestFromHistory
+        from prompt_toolkit.completion import ThreadedCompleter
 
 
         _completer = SlashCommandCompleter(
@@ -12039,7 +12040,13 @@ class HermesCLI(CLIAgentSetupMixin, CLICommandsMixin):
             wrap_lines=True,
             read_only=Condition(lambda: bool(cli_ref._command_running)),
             history=FileHistory(str(self._history_file)),
-            completer=_completer,
+            # complete_while_typing fires the completer on every keystroke. The
+            # completer does blocking work — fuzzy @-file indexing shells out to
+            # rg/fd (up to a 2s timeout) and path completion hits os.listdir/stat
+            # — so running it inline would stall the render loop on each key (very
+            # noticeable on WSL2/slow filesystems). ThreadedCompleter moves it off
+            # the UI event loop, keeping typing responsive.
+            completer=ThreadedCompleter(_completer),
             complete_while_typing=True,
             auto_suggest=SlashCommandAutoSuggest(
                 history_suggest=AutoSuggestFromHistory(),

hermes_cli/commands.py

@@ -1280,6 +1280,10 @@ class SlashCommandCompleter(Completer):
         current word doesn't look like a path.  A word is path-like when
         it starts with ``./``, ``../``, ``~/``, ``/``, or contains a
         ``/`` separator (e.g. ``src/main.py``).
+
+        Tokens containing a ``://`` scheme separator (e.g. URLs like
+        ``https://example.com/x``) are excluded even though they contain a
+        ``/`` — they are never useful local-path completions.
         """
         if not text:
             return None
@@ -1291,6 +1295,12 @@ class SlashCommandCompleter(Completer):
         word = text[i + 1:]
         if not word:
             return None
+        # URLs contain "/" but are not local paths. Treating them as paths fires
+        # os.listdir on every keystroke while typing/pasting a link (e.g. an
+        # https:// URL becomes a listdir of "https:") — pure latency, never a
+        # useful completion. Skip any token with a scheme separator.
+        if "://" in word:
+            return None
         # Only trigger path completion for path-like tokens
         if word.startswith(("./", "../", "~/", "/")) or "/" in word:
             return word

tests/hermes_cli/test_path_completion.py

@@ -59,6 +59,32 @@ class TestExtractPathWord:
     def test_just_tilde_slash(self):
         assert SlashCommandCompleter._extract_path_word("~/") == "~/"
 
+    def test_url_is_not_treated_as_path(self):
+        # A URL contains "/" so the bare slash heuristic would otherwise return
+        # it as a path word, firing os.listdir("https:") on every keystroke.
+        assert SlashCommandCompleter._extract_path_word("see https://paste.rs/abc") is None
+
+    def test_http_url_is_not_treated_as_path(self):
+        assert SlashCommandCompleter._extract_path_word("ref http://example.com/x") is None
+
+    def test_scheme_alone_is_enough_to_reject(self):
+        # The "://" scheme separator is the signal, even before any path part
+        # has been typed.
+        assert SlashCommandCompleter._extract_path_word("ssh://host") is None
+
+    def test_path_word_with_colon_but_no_scheme_still_resolves(self):
+        # Only the "://" scheme separator should reject; a bare colon inside a
+        # real path token must not regress path detection.
+        assert (
+            SlashCommandCompleter._extract_path_word("open ./a:b/c.py") == "./a:b/c.py"
+        )
+
+    def test_ordinary_path_unaffected_by_url_guard(self):
+        assert (
+            SlashCommandCompleter._extract_path_word("edit src/pkg/mod.py")
+            == "src/pkg/mod.py"
+        )
+
 
 class TestPathCompletions:
     def test_lists_current_directory(self, tmp_path):
@@ -155,6 +181,23 @@ class TestIntegration:
         completions = list(completer.get_completions(doc, event))
         assert completions == []
 
+    def test_url_does_not_touch_filesystem(self, completer, monkeypatch):
+        # Regression for laggy typing: a URL token contains "/", so before the
+        # scheme guard it reached _path_completions and called os.listdir on
+        # every keystroke. Assert no completions AND that the filesystem is
+        # never touched while a URL is under the cursor.
+        import hermes_cli.commands as commands_mod
+
+        def _fail(*_args, **_kwargs):
+            raise AssertionError("os.listdir must not run for a URL token")
+
+        monkeypatch.setattr(commands_mod.os, "listdir", _fail)
+
+        text = "open https://paste.rs/abc"
+        doc = Document(text, cursor_position=len(text))
+        event = MagicMock()
+        assert list(completer.get_completions(doc, event)) == []
+
     def test_absolute_path_triggers_completion(self, completer):
         doc = Document("check /etc/hos", cursor_position=14)
         event = MagicMock()