Extensions in static file aren't available via extension methods

[MikeEdgar]

When we load an OAS 3.1 document from JSON/YAML, unknown fields are not currently identified as extensions since they are being added via set. Either Schema#set should be aware of the known properties so that unknown properties are internally identified as extensions, or we should call addExtension when processing these properties:

smallrye-open-api/core/src/main/java/io/smallrye/openapi/runtime/io/media/SchemaIO.java

Lines 126 to 134 in 9cf2fed

	// Read unknown fields
	for (Entry<String, V> entry : jsonIO().properties(node)) {
	String name = entry.getKey();
	V fieldNode = entry.getValue();
	if (!PROPERTIES_DATA_TYPES.containsKey(name) && !name.equals(PROP_TYPE) && !name.equals(PROP_NAME)
	&& !name.equals(PROP_REF)) {
	schema.set(name, jsonIO().fromJson(fieldNode));
	}
	}

[Azquelt]

We discussed this at the call today. It's a bit confusing, Schema has separate get and set methods for setting arbitrary properties, and Extensible says that extensions should begin "x-". On the other hand, we don't enforce the extension key prefix afaik and it seems intuitive that anything that's not a known field is an extension.

We noted the following things to check:

• What do we do when reading and writing OAS 3.0 documents? Extensions there are required to start x-
• Do we have any TCK tests regarding extensions for OAS 3.1 schemas?

We also noted that currently, x- keys do not appear as extensions either.

[MikeEdgar]

What do we do when reading and writing OAS 3.0 documents? Extensions there are required to start x-

• For 3.1 schemas, extensions are populated directly on the schema using set
• For 3.0 schemas, extensions are loaded using ExtensionIO, which populates the schema via addExtension and filters the input properties by the x- prefix.
• For other object types, ExtensionIO is used to determine if a property is an extension (x-) and adding the key/value via addExtension.

Do we have any TCK tests regarding extensions for OAS 3.1 schemas?

I was unable to locate any TCK tests that check reading of extensions from a static file - only annotations are checked.