feat: do validate in signature inference

src/promptflow-devkit/promptflow/_sdk/operations/_flow_operations.py

@@ -1027,7 +1027,7 @@ def _merge_signature(extracted, signature_overrides):
         return signature
 
     @monitor_operation(activity_name="pf.flows._infer_signature", activity_type=ActivityType.INTERNALCALL)
-    def _infer_signature(self, entry: Callable, keep_entry: bool = False) -> Tuple[dict, Path]:
+    def _infer_signature(self, entry: Callable, keep_entry: bool = False, validate: bool = True) -> Tuple[dict, Path]:
         """Infer signature of a flow entry.
 
         Note that this is a Python only feature.
@@ -1047,9 +1047,13 @@ def _infer_signature(self, entry: Callable, keep_entry: bool = False) -> Tuple[d
 
         flow_meta = generate_flow_meta_dict_by_object(func, cls)
         source_path = Path(inspect.getfile(entry))
-        if keep_entry:
-            # TODO: should we handle the case that entry is not defined in root level of the source?
-            flow_meta["entry"] = f"{source_path.stem}:{entry.__name__}"
+        # TODO: should we handle the case that entry is not defined in root level of the source?
+        flow_meta["entry"] = f"{source_path.stem}:{entry.__name__}"
+        if validate:
+            flow = FlexFlow(path=source_path, code=source_path.parent, data=flow_meta, entry=flow_meta["entry"])
+            flow._validate(raise_error=True)
+        if not keep_entry:
+            del flow_meta["entry"]
         return flow_meta, source_path.parent
 
     @monitor_operation(activity_name="pf.flows._save", activity_type=ActivityType.INTERNALCALL)
@@ -1113,7 +1117,7 @@ def _save(
                 "Code path will be the parent of entry source " "and can't be customized when entry is a callable."
             )
         else:
-            entry_meta, code = self._infer_signature(entry, keep_entry=True)
+            entry_meta, code = self._infer_signature(entry, keep_entry=True, validate=False)
 
         data = self._merge_signature(entry_meta, signature)
         data["entry"] = entry_meta["entry"]

src/promptflow/tests/sdk_cli_test/e2etests/test_flow_save.py

@@ -38,6 +38,14 @@ def __call__(self, text: str) -> str:
         return f"Hello {text} via {self.connection.name}!"
 
 
+class GlobalHelloWithInvalidInit:
+    def __init__(self, connection: AzureOpenAIConnection, words: list):
+        self.connection = connection
+
+    def __call__(self, text: str) -> str:
+        return f"Hello {text} via {self.connection.name}!"
+
+
 def global_hello(text: str) -> str:
     return f"Hello {text}!"
 
@@ -377,7 +385,7 @@ def test_pf_save_callable_class(self):
             },
         }
 
-    def test_pf_save_callable_object(self):
+    def test_pf_save_callable_function(self):
         pf = PFClient()
         target_path = f"{FLOWS_DIR}/saved/hello_callable"
         if os.path.exists(target_path):
@@ -401,3 +409,22 @@ def test_pf_save_callable_object(self):
                 },
             },
         }
+
+    def test_infer_signature(self):
+        pf = PFClient()
+        flow_meta, code = pf.flows._infer_signature(entry=global_hello)
+        assert flow_meta == {
+            "inputs": {
+                "text": {
+                    "type": "string",
+                }
+            },
+            "outputs": {
+                "output": {
+                    "type": "string",
+                },
+            },
+        }
+
+        with pytest.raises(UserErrorException, match="Schema validation failed: {'init.words.type'"):
+            pf.flows._infer_signature(entry=GlobalHelloWithInvalidInit)