fix: add default models to Anthropic and make sure template is updated (#5839)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

src/backend/tests/unit/api/v1/test_endpoints.py

@@ -1,9 +1,12 @@
+import inspect
 from typing import Any
 
 from aiofile import async_open
 from fastapi import status
 from httpx import AsyncClient
 from langflow.api.v1.schemas import UpdateCustomComponentRequest
+from langflow.components.agents.agent import AgentComponent
+from langflow.custom.utils import build_custom_component_template
 
 
 async def test_get_version(client: AsyncClient):
@@ -46,3 +49,59 @@ async def test_update_component_outputs(client: AsyncClient, logged_in_headers:
     assert response.status_code == status.HTTP_200_OK
     output_names = [output["name"] for output in result["outputs"]]
     assert "tool_output" in output_names
+
+
+async def test_update_component_model_name_options(client: AsyncClient, logged_in_headers: dict):
+    """Test that model_name options are updated when selecting a provider."""
+    component = AgentComponent()
+    component_node, cc_instance = build_custom_component_template(
+        component,
+    )
+
+    # Initial template with OpenAI as the provider
+    template = component_node["template"]
+    current_model_names = template["model_name"]["options"]
+
+    # load the code from the file at langflow.components.agents.agent.py asynchronously
+    # we are at str/backend/tests/unit/api/v1/test_endpoints.py
+    # find the file by using the class AgentComponent
+    agent_component_file = inspect.getsourcefile(AgentComponent)
+    async with async_open(agent_component_file, encoding="utf-8") as f:
+        code = await f.read()
+
+    # Create the request to update the component
+    request = UpdateCustomComponentRequest(
+        code=code,
+        frontend_node=component_node,
+        field="agent_llm",
+        field_value="Anthropic",
+        template=template,
+    )
+
+    # Make the request to update the component
+    response = await client.post("api/v1/custom_component/update", json=request.model_dump(), headers=logged_in_headers)
+    result = response.json()
+
+    # Verify the response
+    assert response.status_code == status.HTTP_200_OK, f"Response: {response.json()}"
+    assert "template" in result
+    assert "model_name" in result["template"]
+    assert isinstance(result["template"]["model_name"]["options"], list)
+    assert len(result["template"]["model_name"]["options"]) > 0, (
+        f"Model names: {result['template']['model_name']['options']}"
+    )
+    assert current_model_names != result["template"]["model_name"]["options"], (
+        f"Current model names: {current_model_names}, New model names: {result['template']['model_name']['options']}"
+    )
+    # Now test with Custom provider
+    template["agent_llm"]["value"] = "Custom"
+    request.field_value = "Custom"
+    request.template = template
+
+    response = await client.post("api/v1/custom_component/update", json=request.model_dump(), headers=logged_in_headers)
+    result = response.json()
+
+    # Verify that model_name is not present for Custom provider
+    assert response.status_code == status.HTTP_200_OK
+    assert "template" in result
+    assert "model_name" not in result["template"]