test(optional): +x1 TC to check selective optionals with same out...

+ enh TC with parallel.
+ Scavenged from yahoo#20.

Author: ankostis

test/test_graphkit.py

@@ -445,6 +445,68 @@ def addplusplus(a, b, c=0):
     assert results['sum'] == sum(named_inputs.values())
 
 
+def test_optional_per_function_with_same_output():
+    # Test that the same need can be both optional and not on different operations.
+    #
+    ## ATTENTION, the selected function is NOT the one with more inputs
+    # but the 1st satisfiable function added in the network.
+
+    add_op = operation(name='add', needs=['a', 'b'], provides='a+b')(add)
+    sub_op_optional = operation(
+        name='sub_opt', needs=['a', modifiers.optional('b')], provides='a+b'
+    )(lambda a, b=10: a - b)
+    
+    # Normal order
+    #
+    pipeline = compose(name='partial_optionals')(add_op, sub_op_optional)
+    #
+    named_inputs = {'a': 1, 'b': 2}
+    assert pipeline(named_inputs) == {'a': 1, 'a+b': 3, 'b': 2}
+    assert pipeline(named_inputs, ['a+b']) == {'a+b': 3}
+    #
+    named_inputs = {'a': 1}
+    assert pipeline(named_inputs) == {'a': 1, 'a+b': -9}
+    assert pipeline(named_inputs, ['a+b']) == {'a+b': -9}
+
+    # Inverse op order
+    #
+    pipeline = compose(name='partial_optionals')(sub_op_optional, add_op)
+    #
+    named_inputs = {'a': 1, 'b': 2}
+    assert pipeline(named_inputs) == {'a': 1, 'a+b': -1, 'b': 2}
+    assert pipeline(named_inputs, ['a+b']) == {'a+b': -1}
+    #
+    named_inputs = {'a': 1}
+    assert pipeline(named_inputs) == {'a': 1, 'a+b': -9}
+    assert pipeline(named_inputs, ['a+b']) == {'a+b': -9}
+
+    # PARALLEL + Normal order
+    #
+    pipeline = compose(name='partial_optionals')(add_op, sub_op_optional)
+    pipeline.set_execution_method("parallel")
+    #
+    named_inputs = {'a': 1, 'b': 2}
+    assert pipeline(named_inputs) == {'a': 1, 'a+b': 3, 'b': 2}
+    assert pipeline(named_inputs, ['a+b']) == {'a+b': 3}
+    #
+    named_inputs = {'a': 1}
+    assert pipeline(named_inputs) == {'a': 1, 'a+b': -9}
+    assert pipeline(named_inputs, ['a+b']) == {'a+b': -9}
+
+    # PARALLEL + Inverse op order
+    #
+    pipeline = compose(name='partial_optionals')(sub_op_optional, add_op)
+    pipeline.set_execution_method("parallel")
+    #
+    named_inputs = {'a': 1, 'b': 2}
+    assert pipeline(named_inputs) == {'a': 1, 'a+b': -1, 'b': 2}
+    assert pipeline(named_inputs, ['a+b']) == {'a+b': -1}
+    #
+    named_inputs = {'a': 1}
+    assert pipeline(named_inputs) == {'a': 1, 'a+b': -9}
+    assert pipeline(named_inputs, ['a+b']) == {'a+b': -9}
+
+
 def test_deleted_optional():
     # Test that DeleteInstructions included for optionals do not raise
     # exceptions when the corresponding input is not prodided.