use MISSING vs None in parameter inference (#499)

Signed-off-by: Flaviu Vadan <[email protected]>

.github/workflows/cicd.yaml

@@ -5,12 +5,14 @@ on:
     branches:
       - main
       - hera/v5
+      - hera/v4-n-n
     paths:
       - "src/**"
   pull_request:
     branches:
       - main
       - hera/v5
+      - hera/v4-n-n
     paths:
       - "src/**"
 

src/hera/task.py

@@ -34,7 +34,7 @@
 from hera.memoize import Memoize
 from hera.metric import Metric, Metrics
 from hera.operator import Operator
-from hera.parameter import Parameter
+from hera.parameter import Parameter, MISSING
 from hera.port import ContainerPort
 from hera.resource_template import ResourceTemplate
 from hera.resources import Resources
@@ -696,12 +696,12 @@ def _deduce_input_params_from_source(self) -> List[Parameter]:
 
         # If there are any kwargs arguments associated with the function signature,
         # we store these as we can set them as default values for argo arguments
-        source_signature: Dict[str, Optional[str]] = {}
+        source_signature: Dict[str, Optional[Any]] = {}
         for p in inspect.signature(self.source).parameters.values():
             if p.default != inspect.Parameter.empty and p.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD:
                 source_signature[p.name] = p.default
             else:
-                source_signature[p.name] = None
+                source_signature[p.name] = MISSING
 
         # Deduce input parameters from function source. Only add those which haven't been explicitly set in inputs
         input_params_names = [p.name for p in self.inputs if isinstance(p, Parameter)]
@@ -772,7 +772,7 @@ def _deduce_input_params_from_source(self) -> List[Parameter]:
             # Verify that we're utilizing 'item'
             if not any([p.contains_item for p in self.inputs + deduced_params]):  # type: ignore
                 raise ValueError(
-                    "`with_param` or `with_sequence` items are utilized in inputs, nor could they be deduced"
+                    "`with_param` or `with_sequence` items are not utilized in inputs, nor could they be deduced"
                 )
 
         return deduced_params

tests/test_task.py

@@ -832,7 +832,7 @@ def test_task_uses_sequences(self):
         assert t.with_sequence.format == "abc"
 
     def test_task_utilize_items(self, no_op):
-        error_string = "`with_param` or `with_sequence` items are utilized in inputs, nor could they be deduced"
+        error_string = "`with_param` or `with_sequence` items are not utilized in inputs, nor could they be deduced"
         with pytest.raises(ValueError) as e:
             Task("t", no_op, with_sequence=Sequence("abc", start=1, end=42))
         assert str(e.value) == error_string