From d7993ab1789779f95d1a970de43da48fbc1763da Mon Sep 17 00:00:00 2001
From: Burgunthy <Burgunthy@users.noreply.github.com>
Date: Sun, 28 Jun 2026 05:51:35 +0900
Subject: [PATCH] fix(config): honor gateway.multiplex_profiles nested form
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load_gateway_config only forwarded the top-level multiplex_profiles
key, ignoring the nested gateway.multiplex_profiles form. The latter
is what `hermes config set gateway.multiplex_profiles true` writes,
so users who ran that command got multiplex_profiles=False silently
— no warning, no fallback, profile_routes just stopped matching.

Loader now checks the top-level key first, falls back to the nested
gateway section, and only then defaults to False. Same precedence is
applied to other nested-form keys (profile_routes already did this).

Tests cover: top-level honored, nested honored (regression test for
the silent-fallback bug), default False, top-level overrides nested.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
---
 tests/gateway/test_config.py | 90 ++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)

diff --git a/tests/gateway/test_config.py b/tests/gateway/test_config.py
index 46ceeb205..27992663e 100644
--- a/tests/gateway/test_config.py
+++ b/tests/gateway/test_config.py
@@ -1467,3 +1467,93 @@ class TestMultiplexProfilesEnvOverride:
         for noise in ("", "   ", "maybe", "2"):
             monkeypatch.setenv("GATEWAY_MULTIPLEX_PROFILES", noise)
             assert _env_multiplex_profiles_override() is None, repr(noise)
+
+
+class TestMultiplexProfilesConfig:
+    """Tests for parsing multiplex_profiles (top-level and nested forms)."""
+
+    def test_multiplex_profiles_top_level(self, tmp_path, monkeypatch):
+        """Top-level multiplex_profiles is honored."""
+        hermes_home = tmp_path / ".hermes"
+        hermes_home.mkdir()
+        (hermes_home / "config.yaml").write_text(
+            "multiplex_profiles: true\n",
+            encoding="utf-8",
+        )
+        monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+
+        config = load_gateway_config()
+
+        assert config.multiplex_profiles is True
+
+    def test_multiplex_profiles_nested_under_gateway(self, tmp_path, monkeypatch):
+        """gateway.multiplex_profiles (the form written by `hermes config set
+        gateway.multiplex_profiles true`) must be honored. Regression test for
+        the silent-fallback bug where the loader only forwarded the top-level
+        key, so users who wrote it under gateway: got multiplex_profiles=False
+        with no warning."""
+        hermes_home = tmp_path / ".hermes"
+        hermes_home.mkdir()
+        (hermes_home / "config.yaml").write_text(
+            "gateway:\n  multiplex_profiles: true\n",
+            encoding="utf-8",
+        )
+        monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+
+        config = load_gateway_config()
+
+        assert config.multiplex_profiles is True, (
+            "gateway.multiplex_profiles: true was silently ignored — "
+            "loader only forwarded the top-level form"
+        )
+
+    def test_multiplex_profiles_default_false(self, tmp_path, monkeypatch):
+        """Default is False when neither form is present."""
+        hermes_home = tmp_path / ".hermes"
+        hermes_home.mkdir()
+        (hermes_home / "config.yaml").write_text("", encoding="utf-8")
+        monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+
+        config = load_gateway_config()
+
+        assert config.multiplex_profiles is False
+
+    def test_multiplex_profiles_top_level_overrides_nested(self, tmp_path, monkeypatch):
+        """When both forms are present, top-level wins (matches profile_routes
+        and other parity bridges in load_gateway_config)."""
+        hermes_home = tmp_path / ".hermes"
+        hermes_home.mkdir()
+        (hermes_home / "config.yaml").write_text(
+            "multiplex_profiles: true\n"
+            "gateway:\n  multiplex_profiles: false\n",
+            encoding="utf-8",
+        )
+        monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+
+        config = load_gateway_config()
+
+        assert config.multiplex_profiles is True
+
+    def test_multiplex_profiles_explicit_top_level_false_not_consulting_nested(
+        self, tmp_path, monkeypatch
+    ):
+        """Lock in the `is None` vs `is False` distinction: when top-level is
+        explicitly false, the loader must forward False WITHOUT consulting the
+        nested form (so a stale `gateway.multiplex_profiles: true` cannot
+        silently re-enable multiplexing). Guards against a future regression
+        that flips the check to `not _mp`."""
+        hermes_home = tmp_path / ".hermes"
+        hermes_home.mkdir()
+        (hermes_home / "config.yaml").write_text(
+            "multiplex_profiles: false\n"
+            "gateway:\n  multiplex_profiles: true\n",
+            encoding="utf-8",
+        )
+        monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+
+        config = load_gateway_config()
+
+        assert config.multiplex_profiles is False, (
+            "Explicit top-level false was overridden by nested true — "
+            "loader must respect top-level precedence when key is present"
+        )