BaseCloudEvent#readExtensions does not support DatarefExtension

[wong-git]

Marked as general TODO, but it should handle URI since that is the type of the value for a DatarefExtension

[slinkydeveloper]

The issue is not clear to me here, are you proposing to handle URI as a type in CloudEventAttributes?

[wong-git]

Not in CloudEventAttributes but in the existing DatarefExtension. This is an example of the code:

var cloudEventBuilder = CloudEventBuilder.v1();
...
var datarefExtension = new DatarefExtension();
datarefExtension.setDataref(URI.create(...));
cloudEventBuilder.withExtension(datarefExtension);
return new ProducerRecord<>(topic, key, cloudEventBuilder.build());

But this then results in BaseCloudEvent#readExtensions throwing IllegalStateException because the DatarefExtensions value is a URI.

Just to note, DatarefExtension supports conversion on deserializing by taking the String value in the Kafka headers and converting that to a URI.

[slinkydeveloper]

This definitely sounds like a bug, DatarefExtension#getValue should return only valid extension types (String, Boolean or Number). Can you provide a fix for it?

[slinkydeveloper]

Explicited the return types in the javadoc too b68f585

[wong-git]

By "provide" I'm guessing you mean submit a PR for it. Will do.