Add test caching (#5)

Author: hinthornw

.github/workflows/integration-tests.yml

@@ -39,5 +39,6 @@ jobs:
           TAVILY_API_KEY: ${{ secrets.TAVILY_API_KEY }}
           LANGSMITH_API_KEY: ${{ secrets.LANGSMITH_API_KEY }}
           LANGSMITH_TRACING: true
+          LANGSMITH_TEST_CACHE: tests/cassettes
         run: |
           uv run pytest tests/integration_tests

src/react_agent/graph.py

@@ -7,7 +7,6 @@
 from typing import Dict, List, Literal, cast
 
 from langchain_core.messages import AIMessage
-from langchain_core.prompts import ChatPromptTemplate
 from langchain_core.runnables import RunnableConfig
 from langgraph.graph import StateGraph
 from langgraph.prebuilt import ToolNode
@@ -36,25 +35,21 @@ async def call_model(
     """
     configuration = Configuration.from_runnable_config(config)
 
-    # Create a prompt template. Customize this to change the agent's behavior.
-    prompt = ChatPromptTemplate.from_messages(
-        [("system", configuration.system_prompt), ("placeholder", "{messages}")]
-    )
-
     # Initialize the model with tool binding. Change the model or add more tools here.
     model = load_chat_model(configuration.model).bind_tools(TOOLS)
 
-    # Prepare the input for the model, including the current system time
-    message_value = await prompt.ainvoke(
-        {
-            "messages": state.messages,
-            "system_time": datetime.now(tz=timezone.utc).isoformat(),
-        },
-        config,
+    # Format the system prompt. Customize this to change the agent's behavior.
+    system_message = configuration.system_prompt.format(
+        system_time=datetime.now(tz=timezone.utc).isoformat()
     )
 
     # Get the model's response
-    response = cast(AIMessage, await model.ainvoke(message_value, config))
+    response = cast(
+        AIMessage,
+        await model.ainvoke(
+            [{"role": "system", "content": system_message}, *state.messages], config
+        ),
+    )
 
     # Handle the case when it's the last step and the model still wants to use a tool
     if state.is_last_step and response.tool_calls:
@@ -73,15 +68,15 @@ async def call_model(
 
 # Define a new graph
 
-workflow = StateGraph(State, input=InputState, config_schema=Configuration)
+builder = StateGraph(State, input=InputState, config_schema=Configuration)
 
 # Define the two nodes we will cycle between
-workflow.add_node(call_model)
-workflow.add_node("tools", ToolNode(TOOLS))
+builder.add_node(call_model)
+builder.add_node("tools", ToolNode(TOOLS))
 
 # Set the entrypoint as `call_model`
 # This means that this node is the first one called
-workflow.add_edge("__start__", "call_model")
+builder.add_edge("__start__", "call_model")
 
 
 def route_model_output(state: State) -> Literal["__end__", "tools"]:
@@ -108,7 +103,7 @@ def route_model_output(state: State) -> Literal["__end__", "tools"]:
 
 
 # Add a conditional edge to determine the next step after `call_model`
-workflow.add_conditional_edges(
+builder.add_conditional_edges(
     "call_model",
     # After call_model finishes running, the next node(s) are scheduled
     # based on the output from route_model_output
@@ -117,11 +112,11 @@ def route_model_output(state: State) -> Literal["__end__", "tools"]:
 
 # Add a normal edge from `tools` to `call_model`
 # This creates a cycle: after using tools, we always return to the model
-workflow.add_edge("tools", "call_model")
+builder.add_edge("tools", "call_model")
 
-# Compile the workflow into an executable graph
+# Compile the builder into an executable graph
 # You can customize this by adding interrupt points for state updates
-graph = workflow.compile(
+graph = builder.compile(
     interrupt_before=[],  # Add node names here to update state before they're called
     interrupt_after=[],  # Add node names here to update state after they're called
 )