validate task inputs and outputs when creating task

aiida_workgraph/decorator.py

@@ -39,6 +39,8 @@ def create_task(tdata):
 
     tdata["type_mapping"] = type_mapping
     tdata["metadata"]["node_type"] = tdata["metadata"].pop("task_type")
+    tdata["inputs"] = validate_task_inout(tdata["inputs"], "inputs")
+    tdata["outputs"] = validate_task_inout(tdata["outputs"], "outputs")
     return create_node(tdata)
 
 
@@ -130,12 +132,6 @@ def build_task(
     """Build task from executor."""
     from aiida_workgraph.workgraph import WorkGraph
 
-    if inputs:
-        inputs = validate_task_inout(inputs, "inputs")
-
-    if outputs:
-        outputs = validate_task_inout(outputs, "outputs")
-
     if isinstance(executor, WorkGraph):
         return build_task_from_workgraph(executor)
     elif isinstance(executor, str):

tests/test_decorator.py

@@ -3,6 +3,18 @@
 from typing import Callable
 
 
+def test_custom_outputs():
+    """Test custom outputs."""
+
+    @task(outputs=["sum", {"name": "product", "identifier": "workgraph.any"}])
+    def add_multiply(x, y):
+        return {"sum": x + y, "product": x * y}
+
+    n = add_multiply.task()
+    assert "sum" in n.outputs.keys()
+    assert "product" in n.outputs.keys()
+
+
 @pytest.fixture(params=["decorator_factory", "decorator"])
 def task_calcfunction(request):
     if request.param == "decorator_factory":