Adding event_supported to converters

 - this method validates whether a converter can process the event,
   in case of structured converter this method does nothing,
   in case of binary converter this method raise an exception if an event is not v0.2
 - adding (un)marshaller validation on being a callable object
 - tests added

Signed-off-by: Denis Makogon <[email protected]>

Author: denismakogon

cloudevents/sdk/converters/base.py

@@ -25,6 +25,9 @@ def read(self, event, headers: dict, body: typing.IO,
              data_unmarshaller: typing.Callable) -> base.BaseEvent:
         raise Exception("not implemented")
 
+    def event_supported(self, event):
+        raise Exception("not implemented")
+
     def can_read(self, content_type):
         raise Exception("not implemented")
 

cloudevents/sdk/converters/binary.py

@@ -28,6 +28,10 @@ class BinaryHTTPCloudEventConverter(base.Converter):
     def can_read(self, content_type):
         return True
 
+    def event_supported(self, event):
+        if type(event) not in self.SUPPORTED_VERSIONS:
+            raise exceptions.UnsupportedEvent(type(event))
+
     def read(self,
              event: event_base.BaseEvent,
              headers: dict, body: typing.IO,
@@ -39,9 +43,6 @@ def read(self,
 
     def write(self, event: event_base.BaseEvent,
               data_marshaller: typing.Callable) -> (dict, typing.IO):
-        if not isinstance(data_marshaller, typing.Callable):
-            raise exceptions.InvalidDataMarshaller()
-
         return event.MarshalBinary(data_marshaller)
 
 

cloudevents/sdk/converters/structured.py

@@ -14,7 +14,6 @@
 
 import typing
 
-from cloudevents.sdk import exceptions
 from cloudevents.sdk.converters import base
 from cloudevents.sdk.event import base as event_base
 
@@ -26,6 +25,10 @@ class JSONHTTPCloudEventConverter(base.Converter):
     def can_read(self, content_type):
         return content_type == "application/cloudevents+json"
 
+    def event_supported(self, event):
+        # structured format supported by both spec 0.1 and 0.2
+        pass
+
     def read(self, event: event_base.BaseEvent,
              headers: dict,
              body: typing.IO,
@@ -36,9 +39,6 @@ def read(self, event: event_base.BaseEvent,
     def write(self,
               event: event_base.BaseEvent,
               data_marshaller: typing.Callable) -> (dict, typing.IO):
-        if not isinstance(data_marshaller, typing.Callable):
-            raise exceptions.InvalidDataMarshaller()
-
         return {}, event.MarshalJSON(data_marshaller)
 
 

cloudevents/sdk/exceptions.py

@@ -20,6 +20,13 @@ def __init__(self, event_class):
                          "'{0}'".format(event_class))
 
 
+class InvalidDataUnmarshaller(Exception):
+
+    def __init__(self):
+        super().__init__(
+            "Invalid data unmarshaller, is not a callable")
+
+
 class InvalidDataMarshaller(Exception):
 
     def __init__(self):

cloudevents/sdk/marshaller.py

@@ -55,11 +55,15 @@ def FromRequest(self, event: event_base.BaseEvent,
         :return: a CloudEvent
         :rtype: event_base.BaseEvent
         """
+        if not isinstance(data_unmarshaller, typing.Callable):
+            raise exceptions.InvalidDataUnmarshaller()
+
         content_type = headers.get(
             "content-type", headers.get("Content-Type"))
 
         for _, cnvrtr in self.__converters.items():
             if cnvrtr.can_read(content_type):
+                cnvrtr.event_supported(event)
                 return cnvrtr.read(event, headers, body, data_unmarshaller)
 
         raise exceptions.UnsupportedEventConverter(content_type)
@@ -78,6 +82,9 @@ def ToRequest(self, event: event_base.BaseEvent,
         :return: dict of HTTP headers and stream of HTTP request body
         :rtype: tuple
         """
+        if not isinstance(data_marshaller, typing.Callable):
+            raise exceptions.InvalidDataMarshaller()
+
         if converter_type in self.__converters:
             cnvrtr = self.__converters.get(converter_type)
             return cnvrtr.write(event, data_marshaller)

cloudevents/tests/test_event_from_request_converter.py

@@ -68,7 +68,7 @@ def test_binary_converter_v01():
     pytest.raises(
         exceptions.UnsupportedEvent,
         m.FromRequest,
-        v01.Event, {}, None, None)
+        v01.Event, {}, None, lambda x: x)
 
 
 def test_unsupported_converter_v01():
@@ -81,7 +81,7 @@ def test_unsupported_converter_v01():
     pytest.raises(
         exceptions.UnsupportedEventConverter,
         m.FromRequest,
-        v01.Event, {}, None, None)
+        v01.Event, {}, None, lambda x: x)
 
 
 def test_structured_converter_v01():
@@ -114,3 +114,35 @@ def test_default_http_marshaller():
     assert event is not None
     assert event.Get("type") == (data.ce_type, True)
     assert event.Get("id") == (data.ce_id, True)
+
+
+def test_unsupported_event_configuration():
+    m = marshaller.NewHTTPMarshaller(
+        [
+            binary.NewBinaryHTTPCloudEventConverter()
+        ]
+    )
+    pytest.raises(
+        exceptions.UnsupportedEvent,
+        m.FromRequest,
+        v01.Event(),
+        {"Content-Type": "application/cloudevents+json"},
+        io.StringIO(json.dumps(data.ce)),
+        lambda x: x.read()
+    )
+
+
+def test_invalid_data_unmarshaller():
+    m = marshaller.NewDefaultHTTPMarshaller()
+    pytest.raises(
+        exceptions.InvalidDataUnmarshaller,
+        m.FromRequest,
+        v01.Event(), {}, None, None)
+
+
+def test_invalid_data_marshaller():
+    m = marshaller.NewDefaultHTTPMarshaller()
+    pytest.raises(
+        exceptions.InvalidDataMarshaller,
+        m.ToRequest,
+        v01.Event(), "blah", None)