Revert "Enabling implicit output for generic bindings (Azure#1348)" (Azure#1376)

This reverts commit a981fcf. Co-authored-by: root <root@GavinPC>

Author: gavin-aguiar

azure_functions_worker/bindings/generic.py

@@ -52,4 +52,4 @@ def decode(cls, data: datumdef.Datum, *, trigger_metadata) -> typing.Any:
 
  @classmethod
  def has_implicit_output(cls) -> bool:
- return True
+ return False

tests/unittests/test_mock_generic_functions.py

@@ -131,7 +131,7 @@ async def test_mock_generic_should_not_support_implicit_output(self):
  protos.StatusResult.Success)
 
  _, r = await host.invoke_function(
- 'foobar_implicit_output', [
+ 'foobar_as_bytes_no_anno', [
  protos.ParameterBinding(
  name='input',
  data=protos.TypedData(
@@ -140,10 +140,10 @@ async def test_mock_generic_should_not_support_implicit_output(self):
  )
  ]
  )
- # It passes now as we are enabling generic binding to return output
- # implicitly
+ # It should fail here, since generic binding requires
+ # $return statement in function.json to pass output
  self.assertEqual(r.response.result.status,
- protos.StatusResult.Success)
+ protos.StatusResult.Failure)
 
  async def test_mock_generic_should_support_without_datatype(self):
  async with testutils.start_mockhost(
@@ -166,7 +166,7 @@ async def test_mock_generic_should_support_without_datatype(self):
  )
  ]
  )
- # It passes now as we are enabling generic binding to return output
- # implicitly
+ # It should fail here, since the generic binding requires datatype
+ # to be defined in function.json
  self.assertEqual(r.response.result.status,
- protos.StatusResult.Success)
+ protos.StatusResult.Failure)