test(model): cover comma-chain splitting for providers and custom_providers

One regression test per config section feeding the Desktop picker payload:
a volcengine-agent-plan style `default_model` chain under `providers:` and
a `model:` chain under `custom_providers:`. Both assert the raw chain stays
first as the default entry and the split ids follow, deduped in order.

Cases adapted from #50603.

Co-authored-by: LeonSGP43 <cine.dreamer.one@gmail.com>

tests/hermes_cli/test_model_switch_custom_providers.py

@@ -288,6 +288,40 @@ def test_providers_singular_model_does_not_suppress_ollama_native_discovery(monk
     assert ollama["models"] == ["qwen3:latest", "llama3.2:latest"]
 
 
+def test_list_splits_comma_chain_custom_provider_model(monkeypatch):
+    """A comma-separated custom-provider ``model:`` chain surfaces as individual entries.
+
+    Regression (fixes #50557): picker rows are fed from ``list_authenticated_providers``
+    and previously rendered the whole fallback chain as one dropdown entry. The raw chain
+    stays first so the server-side fallback behaviour remains the default pick.
+    """
+    monkeypatch.setattr("agent.models_dev.fetch_models_dev", lambda: {})
+    monkeypatch.setattr(providers_mod, "HERMES_OVERLAYS", {})
+
+    providers = list_authenticated_providers(
+        current_provider="openai-codex",
+        user_providers={},
+        custom_providers=[
+            {
+                "name": "Volcengine Agent Plan",
+                "base_url": "https://ark.cn-beijing.volces.com/api/v3",
+                "model": "deepseek-v4-flash, deepseek-v4-pro, glm-5.2, deepseek-v4-flash",
+            }
+        ],
+        max_models=50,
+    )
+
+    rows = [p for p in providers if p["name"] == "Volcengine Agent Plan"]
+    assert len(rows) == 1
+    assert rows[0]["models"] == [
+        "deepseek-v4-flash, deepseek-v4-pro, glm-5.2, deepseek-v4-flash",
+        "deepseek-v4-flash",
+        "deepseek-v4-pro",
+        "glm-5.2",
+    ]
+    assert rows[0]["total_models"] == 4
+
+
 def test_list_authenticated_providers_can_skip_custom_provider_live_probe(monkeypatch):
     monkeypatch.setattr("agent.models_dev.fetch_models_dev", lambda: {})
     monkeypatch.setattr(providers_mod, "HERMES_OVERLAYS", {})

tests/hermes_cli/test_user_providers_model_switch.py

@@ -213,6 +213,48 @@ def test_list_authenticated_providers_accepts_base_url_and_singular_model(monkey
     assert custom["total_models"] == 3
 
 
+def test_list_authenticated_providers_splits_comma_default_model_chain(monkeypatch):
+    """Comma-separated ``default_model`` chains surface as individually selectable entries.
+
+    Regression (fixes #50557): a volcengine-agent-plan style fallback chain in
+    ``providers:`` rendered as one dropdown entry in the Desktop picker, which
+    feeds off this payload. The raw chain stays first as the default (fallback)
+    pick; the split ids follow, deduped in order.
+    """
+    monkeypatch.setattr("agent.models_dev.fetch_models_dev", lambda: {})
+    monkeypatch.setattr("hermes_cli.providers.HERMES_OVERLAYS", {})
+    monkeypatch.setattr("hermes_cli.models.fetch_api_models", lambda *_a, **_kw: None)
+
+    user_providers = {
+        "volcengine-agent-plan": {
+            "name": "VOLCENGINE-AGENT-PLAN",
+            "base_url": "https://ark.cn-beijing.volces.com/api/v3",
+            "default_model": "deepseek-v4-flash, deepseek-v4-pro, glm-5.2, deepseek-v4-flash",
+        }
+    }
+
+    providers = list_authenticated_providers(
+        current_provider="volcengine-agent-plan",
+        user_providers=user_providers,
+        custom_providers=[],
+        max_models=50,
+    )
+
+    user_prov = next(
+        (p for p in providers if p.get("is_user_defined") and p["slug"] == "volcengine-agent-plan"),
+        None,
+    )
+
+    assert user_prov is not None
+    assert user_prov["models"] == [
+        "deepseek-v4-flash, deepseek-v4-pro, glm-5.2, deepseek-v4-flash",
+        "deepseek-v4-flash",
+        "deepseek-v4-pro",
+        "glm-5.2",
+    ]
+    assert user_prov["total_models"] == 4
+
+
 def test_list_authenticated_providers_dedupes_when_user_and_custom_overlap(monkeypatch):
     """When the same slug appears in both ``providers:`` dict and
     ``custom_providers:`` list, emit exactly one row (providers: dict wins