Fix null value in ResultPath (aws#48)

* Fix null value in ResultPath Fixes aws#45 * Add unit test covering default ResultPath * Fix null values in InputPath and OutputPath

Author: tuliocasagrande

src/stepfunctions/steps/states.py

@@ -66,9 +66,10 @@ def _replace_placeholders(self, params):
 
  def to_dict(self):
  result = {}
+ fields_accepted_as_none = ('result_path', 'input_path', 'output_path')
  # Common fields
  for k, v in self.fields.items():
- if v is not None:
+ if v is not None or k in fields_accepted_as_none:
  k = to_pascalcase(k)
  if k == to_pascalcase(Field.Parameters.value):
  result[k] = self._replace_placeholders(v)

tests/unit/test_steps.py

@@ -346,4 +346,43 @@ def test_retry_fail_for_unsupported_state():
  c1 = Choice('My Choice')
 
  with pytest.raises(ValueError):
- c1.add_catch(Catch(error_equals=["States.NoChoiceMatched"], next_step=Fail("ChoiceFailed")))
+ c1.add_catch(Catch(error_equals=["States.NoChoiceMatched"], next_step=Fail("ChoiceFailed")))
+
+
+def test_paths_none():
+ task_state = Task('Task', resource='arn:aws:lambda:us-east-1:1234567890:function:StartLambda',
+ result_path=None,
+ input_path=None,
+ output_path=None)
+ assert 'ResultPath' in task_state.to_dict()
+ assert task_state.to_dict()['ResultPath'] is None
+
+ assert 'InputPath' in task_state.to_dict()
+ assert task_state.to_dict()['InputPath'] is None
+
+ assert 'OutputPath' in task_state.to_dict()
+ assert task_state.to_dict()['OutputPath'] is None
+
+
+def test_paths_none_converted_to_null():
+ task_state = Task('Task', resource='arn:aws:lambda:us-east-1:1234567890:function:StartLambda',
+ result_path=None,
+ input_path=None,
+ output_path=None)
+ assert '"ResultPath": null' in task_state.to_json()
+ assert '"InputPath": null' in task_state.to_json()
+ assert '"OutputPath": null' in task_state.to_json()
+
+
+def test_default_paths_not_included():
+ task_state = Task('Task', resource='arn:aws:lambda:us-east-1:1234567890:function:StartLambda')
+ assert 'ResultPath' not in task_state.to_dict()
+ assert 'InputPath' not in task_state.to_dict()
+ assert 'OutputPath' not in task_state.to_dict()
+
+
+def test_default_paths_not_converted_to_null():
+ task_state = Task('Task', resource='arn:aws:lambda:us-east-1:1234567890:function:StartLambda')
+ assert '"ResultPath": null' not in task_state.to_json()
+ assert '"InputPath": null' not in task_state.to_json()
+ assert '"OutputPath": null' not in task_state.to_json()