Fix generating signature for empty wsdl messages (#452)

Author: mvantellingen

CHANGES

@@ -5,6 +5,7 @@
    exception (#527)
  - Update packaging (stop using find_packages()) (#529)
  - Properly handle None values when rendering complex types (#526)
+ - Fix generating signature for empty wsdl messages (#452)
 
 
 2.3.0 (2017-08-06)

src/zeep/wsdl/messages/soap.py

@@ -132,7 +132,10 @@ def signature(self, as_output=False):
                     return None
             return self.envelope.type.signature(schema=self.wsdl.types, standalone=False)
 
-        parts = [self.body.type.signature(schema=self.wsdl.types, standalone=False)]
+        if self.body:
+            parts = [self.body.type.signature(schema=self.wsdl.types, standalone=False)]
+        else:
+            parts = []
         if self.header.type._element:
             parts.append('_soapheaders={%s}' % self.header.type.signature(
                 schema=self.wsdl.types, standalone=False))

tests/test_wsdl_messages_document.py

@@ -1321,8 +1321,9 @@ def test_empty_input_parse():
 
     binding = root.bindings['{http://tests.python-zeep.org/}Binding']
     operation = binding.get('getResult')
-    serialized = operation.input.serialize()
+    assert operation.input.signature() == ''
 
+    serialized = operation.input.serialize()
     expected = """
         <?xml version="1.0"?>
         <soap-env:Envelope