Switching from Jackson to Gson might break current behavior

[ruedih]

As mentioned in this pull request (#232), the function worker will switch from Jackson to Gson.

Currently it is possible to only add Jackson annotations as dependency to a function project and to rely on the Jackson features like Ignore, PropertyOrder, CustomRoot on your model classes...

I haven't been able to verify that the new worker version will break the current behavior. But normally Gson does not respect Jackson annotations.

To check

Can you please verify that the function code (https://github.com/ruedih/azure-functions-jackson-vs-gson-example) will still return

{
  "somethingToShow": "should be visible."
}

if you call it with GET http://localhost:7071/api/HttpTrigger-Java and the new "Gson worker"?

Breaking change expected

I'd expect that the change breaks the current behavior and it now returns:

{
  "somethingToShow": "should be visible.",
  "somethingToHide": "should not be visible."
}

Thank you for your help 😺

[pragnagopa]

cc @fabiocav @paulbatum

@Trosky - Yes you are right. It does effect how output bindings are serialized. I will document this as a breaking change as part of our release notes.

For your function, you need to explicitly write the response like this

String result = new ObjectMapper().writeValueAsString(response);        	      

return request.createResponseBuilder(HttpStatus.OK).body(result).build();

[fabiocav]

@pragnagopa I think we're moving forward with the change, correct? Any follow up on this? Can this issue be closed?

[pragnagopa]

Yes. This is in production now. Closing.

[nicenemo]

Possible breaking change.
We use Table-storage from both Java and JavaScript.
Our JavaScript code creates keys with uppercase UUIDs(guids for the .NET heads). In the Java code we have no obvious control over the casing of the keys. This is provided by the serializer used in the the Table-storage-sdk. And in the version that we now use it uses lowercase.

We use uppercase foor UUIDs because SQL server uses uppercase.
In our serializations we configure Gson to use a custom serializer for UUIDs that does an toupper on the created string representation.