isResume

saf-python-sdk/python/saf_python_sdk/advanced_graph/state.py

@@ -222,6 +222,13 @@ class Context:
             return resumed
         raise WaitRequested(_target_to_suspend_payload(target))
 
+    def is_resume(self) -> bool:
+        return self._run._is_resume_execution()
+
+    # Go-style alias.
+    def IsResume(self) -> bool:
+        return self.is_resume()
+
     def publish_to_channel(self, channel: str, value: Any) -> None:
         self._run.publish_nowait(channel, value)
 
@@ -418,6 +425,7 @@ class _GraphEngineRun:
     ) -> dict[str, Any]:
         node_input, resume_event = _unwrap_resume_input(node_input)
         self._set_resume_event(resume_event)
+        self._set_is_resume(resume_event is not None)
         if node_name not in self._nodes:
             raise ValueError(f"Unknown node `{node_name}`")
         node = self._nodes[node_name]
@@ -431,6 +439,7 @@ class _GraphEngineRun:
             return {"suspend": suspend.payload}
         finally:
             self._set_resume_event(None)
+            self._set_is_resume(False)
 
         if isinstance(result, Command):
             update = result.update
@@ -450,6 +459,12 @@ class _GraphEngineRun:
     def _set_resume_event(self, event: dict[str, Any] | None) -> None:
         self._local.resume_event = event
 
+    def _set_is_resume(self, is_resume: bool) -> None:
+        self._local.is_resume = is_resume
+
+    def _is_resume_execution(self) -> bool:
+        return bool(getattr(self._local, "is_resume", False))
+
     def _consume_resume_event(
         self, target: WaitCondition | AnyOfCondition | AllOfCondition
     ) -> WaitForResult | None:

saf-python-sdk/tests/advanced-graph/test_primitives.py

@@ -216,3 +216,35 @@ async def test_all_of_channel_and_timer_marks_both_conditions() -> None:
     assert result["logs"] == ["all_of_channel_timer"]
     assert result["done"] == "ok"
 
+
+async def test_is_resume_avoids_duplicate_side_effects() -> None:
+    graph = AdvancedStateGraph(PrimitiveState)
+    db_writes: list[str] = []
+
+    async def start_node(state: PrimitiveState) -> Command:
+        return Command(
+            update={"counter": 0, "logs": [], "done": None},
+            goto=Send("wait_node", None),
+        )
+
+    async def wait_node(ctx: Context, _input: None, state: PrimitiveState) -> Command:
+        if not ctx.IsResume():
+            # Simulate one-time side effect (e.g. database write).
+            db_writes.append("write")
+        await ctx.wait_for(timer_condition(seconds=0.02))
+        state["logs"].append(f"resume={ctx.IsResume()}")
+        return Command(update=state, goto=Send("finish_node", None))
+
+    async def finish_node(_input: None, state: PrimitiveState) -> dict[str, object]:
+        return {"counter": state["counter"], "logs": state["logs"], "done": "ok"}
+
+    graph.add_entry_node(start_node)
+    graph.add_node(wait_node)
+    graph.add_finish_node(finish_node)
+
+    result = await graph.compile().ainvoke({"counter": 0, "logs": [], "done": None})
+    assert db_writes == ["write"]
+    assert result["counter"] == 0
+    assert result["logs"] == ["resume=True"]
+    assert result["done"] == "ok"
+