Possible Serialization bug?

[No9]

Hi All
Testing the tide websocket implementation using the example message from
https://github.com/cloudevents/spec/blob/master/json-format.md#32-examples

{
    "specversion" : "1.0",
    "type" : "com.example.someevent",
    "source" : "/mycontext",
    "id" : "A234-1234-1234",
    "time" : "2018-04-05T17:31:00Z",
    "comexampleextension1" : "value",
    "comexampleothervalue" : 5,
    "unsetextension": null,
    "datacontenttype" : "text/xml",
    "data" : "<much wow=\"xml\"/>"
}

Specifically this line 205e16a#diff-97633925b0ac8233888bd3bdc2313999cd86c04f1e7e56a62a8cb1e8d58ba5eaR50

let v: Event = serde_json::from_str(&message).unwrap(); 

fails with

thread 'async-std/runtime' panicked at 'called `Result::unwrap()` on an 
`Err` value: Error("data did not match any variant of untagged enum ExtensionValue", 
line: 0, column: 0)', src/main.rs:50:71

If I remove the property set to null "unsetextension": null, the message works as expected.

{
    "specversion" : "1.0",
    "type" : "com.example.someevent",
    "source" : "/mycontext",
    "id" : "A234-1234-1234",
    "time" : "2018-04-05T17:31:00Z",
    "comexampleextension1" : "value",
    "comexampleothervalue" : 5,
    "datacontenttype" : "text/xml",
    "data" : "<much wow=\"xml\"/>"
}

According to the docs null should be treated as unset or omitted
https://github.com/cloudevents/spec/blob/70823088e52b393b4251abd1ab03b6cfa233d427/json-format.md#22-type-system-mapping.

Do you have any preferences for which it should be?

[slinkydeveloper]

Yeah I guess that's an issue we need to solve, do you want to tackle it?

[No9]

I can take a look but is there a preference between omitting vs unset?
My understanding of omitting is discard the property totally where as unset would mean setting the value to None.

[slinkydeveloper]

yes, me too: when null, it's like none