style(langgraph): format conversation state changes

features/steps/conversation_state_management_steps.py

@@ -144,9 +144,7 @@ def step_assert_history_contains_new_message(context: Context) -> None:
     mgr: ConversationStateManager = context.managers["csm"]
     history = mgr.get_full_history()
     contents = [m.get("content") for m in history]
-    assert "new message" in contents, (
-        f"'new message' not found in history: {contents}"
-    )
+    assert "new message" in contents, f"'new message' not found in history: {contents}"
 
 
 # ---------------------------------------------------------------------------
@@ -209,17 +207,13 @@ def step_create_execution_state(context: Context) -> None:
 @then('the ExecutionState current_node should be "node_x"')
 def step_assert_exec_state_current_node(context: Context) -> None:
     es: ExecutionState = context.results["exec_state"]
-    assert es.current_node == "node_x", (
-        f"Expected 'node_x', got {es.current_node!r}"
-    )
+    assert es.current_node == "node_x", f"Expected 'node_x', got {es.current_node!r}"
 
 
 @then("the ExecutionState execution_count should be 3")
 def step_assert_exec_state_execution_count(context: Context) -> None:
     es: ExecutionState = context.results["exec_state"]
-    assert es.execution_count == 3, (
-        f"Expected 3, got {es.execution_count}"
-    )
+    assert es.execution_count == 3, f"Expected 3, got {es.execution_count}"
 
 
 # ---------------------------------------------------------------------------