Require identical parameters

Author: dandavison

temporalio/workflow.py

@@ -1335,6 +1335,7 @@ def _apply_to_class(
         issues: List[str] = []
 
         # Collect run fn and all signal/query/update fns
+        init_fn: Optional[Callable[..., None]] = None
         run_fn: Optional[Callable[..., Awaitable[Any]]] = None
         seen_run_attr = False
         signals: Dict[Optional[str], _SignalDefinition] = {}
@@ -1381,6 +1382,8 @@ def _apply_to_class(
                     )
                 else:
                     queries[query_defn.name] = query_defn
+            elif name == "__init__" and hasattr(member, "__temporal_workflow_init"):
+                init_fn = member
             elif isinstance(member, UpdateMethodMultiParam):
                 update_defn = member._defn
                 if update_defn.name in updates:
@@ -1433,6 +1436,11 @@ def _apply_to_class(
 
         if not seen_run_attr:
             issues.append("Missing @workflow.run method")
+        if init_fn and run_fn:
+            if not _parameters_identical_up_to_naming(init_fn, run_fn):
+                issues.append(
+                    "@workflow.init and @workflow.run method parameters do not match"
+                )
         if issues:
             if len(issues) == 1:
                 raise ValueError(f"Invalid workflow class: {issues[0]}")
@@ -1471,6 +1479,19 @@ def __post_init__(self) -> None:
             object.__setattr__(self, "ret_type", ret_type)
 
 
+def _parameters_identical_up_to_naming(fn1: Callable, fn2: Callable) -> bool:
+    """Return True if the functions have identical parameter lists, ignoring parameter names."""
+
+    def params(fn: Callable) -> List[inspect.Parameter]:
+        # Ignore name when comparing parameters (remaining fields are kind,
+        # default, and annotation).
+        return [p.replace(name="x") for p in inspect.signature(fn).parameters.values()]
+
+    # We require that any type annotations present match exactly; i.e. we do
+    # not support any notion of subtype compatibility.
+    return params(fn1) == params(fn2)
+
+
 # Async safe version of partial
 def _bind_method(obj: Any, fn: Callable[..., Any]) -> Callable[..., Any]:
     # Curry instance on the definition function since that represents an

tests/worker/test_workflow.py

@@ -3902,7 +3902,7 @@ def matches_metric_line(
                 return False
             # Must have labels (don't escape for this test)
             for k, v in at_least_labels.items():
-                if not f'{k}="{v}"' in line:
+                if f'{k}="{v}"' not in line:
                     return False
             return line.endswith(f" {value}")
 
@@ -4856,7 +4856,7 @@ async def assert_scenario(
         update_scenario: Optional[FailureTypesScenario] = None,
     ) -> None:
         logging.debug(
-            f"Asserting scenario %s",
+            "Asserting scenario %s",
             {
                 "workflow": workflow,
                 "expect_task_fail": expect_task_fail,
@@ -6054,7 +6054,7 @@ class WorkflowWithWorkflowInit:
     _expected_update_result = "workflow input value"
 
     @workflow.init
-    def __init__(self, arg: str = "from parameter default") -> None:
+    def __init__(self, arg: str) -> None:
         self.value = arg
 
     @workflow.update
@@ -6084,82 +6084,12 @@ async def run(self, _: str) -> str:
         return self.value
 
 
-@workflow.defn(name="MyWorkflow")
-class WorkflowWithWorkflowInitBaseDecorated:
-    use_workflow_init = True
-
-    @workflow.init
-    def __init__(
-        self, required_param_that_will_be_supplied_by_child_init_method
-    ) -> None:
-        self.value = required_param_that_will_be_supplied_by_child_init_method
-
-    if use_workflow_init:
-        __init__ = workflow.init(__init__)
-
-    @workflow.run
-    async def run(self, _: str): ...
-
-    @workflow.update
-    async def my_update(self) -> str:
-        return self.value
-
-
-class WorkflowWithWorkflowInitBaseUndecorated(WorkflowWithWorkflowInitBaseDecorated):
-    # The base class does not need the @workflow.init decorator
-    use_workflow_init = False
-
-
-@workflow.defn(name="MyWorkflow")
-class WorkflowWithWorkflowInitChild(WorkflowWithWorkflowInitBaseDecorated):
-    use_workflow_init = True
-    _expected_update_result = "workflow input value"
-
-    def __init__(self, arg: str = "from parameter default") -> None:
-        super().__init__("from child __init__")
-        self.value = arg
-
-    if use_workflow_init:
-        __init__ = workflow.init(__init__)
-
-    @workflow.run
-    async def run(self, _: str) -> str:
-        self.value = "set in run method"
-        return self.value
-
-
-@workflow.defn(name="MyWorkflow")
-class WorkflowWithWorkflowInitChildNoWorkflowInit(
-    WorkflowWithWorkflowInitBaseDecorated
-):
-    use_workflow_init = False
-    _expected_update_result = "from parameter default"
-
-    def __init__(self, arg: str = "from parameter default") -> None:
-        super().__init__("from child __init__")
-        self.value = arg
-
-    if use_workflow_init:
-        __init__ = workflow.init(__init__)
-
-    @workflow.run
-    async def run(self, _: str) -> str:
-        self.value = "set in run method"
-        return self.value
-
-
 @pytest.mark.parametrize(
     ["client_cls", "worker_cls"],
     [
         (WorkflowWithoutInit, WorkflowWithoutInit),
         (WorkflowWithNonWorkflowInitInit, WorkflowWithNonWorkflowInitInit),
         (WorkflowWithWorkflowInit, WorkflowWithWorkflowInit),
-        (WorkflowWithWorkflowInitBaseDecorated, WorkflowWithWorkflowInitChild),
-        (WorkflowWithWorkflowInitBaseUndecorated, WorkflowWithWorkflowInitChild),
-        (
-            WorkflowWithWorkflowInitBaseUndecorated,
-            WorkflowWithWorkflowInitChildNoWorkflowInit,
-        ),
     ],
 )
 async def test_update_in_first_wft_sees_workflow_init(