Define trait and extension for adding x- properties to openapi output

[Xtansia]

Description

Defines a custom trait and extension to the OpenAPI converter, to allow adding x- properties to schemas and operations in the OpenAPI output.

For example:

use opensearch.openapi#vendorExtensions

// ...
@vendorExtensions(
    "x-namespace": "cat"
    "x-operation": "indices"
)
operation GetCatIndices {
    input: GetCatIndicesInput,
    output: GetCatIndicesOutput
}

Results in:

          "/_cat/indices": {
            "get": {
                "description": "Returns information about indices: number of primaries and replicas, document counts, disk size, etc.",
                "operationId": "GetCatIndices",
                "parameters": [ ... ],
                "responses": {
                    "200": { ... }
                },
                "x-namespace": "cat",
                "x-operation": "indices"
            }
        },

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[nhtruong]

instead of extendedMetadata can it be renamed to openApiExtensions to clarify the purpose and lock down the scope of this trait?

[reta]

instead of extendedMetadata can it be renamed to openApiExtensions to clarify the purpose of this trait?

Or vendorExtensions [1], quite often used

[1] https://swagger.io/docs/specification/openapi-extensions/

[nhtruong]

Or vendorExtensions [1], quite often used

[1] https://swagger.io/docs/specification/openapi-extensions/

or openApiVendorExtensions (a bit long haha) since, in the context of Smithy, this trait is meant for OpenApi Extentions compatibility and has nothing to do with Smithy itself. We need OpenApi in the name for clarity.

[reta]

@nhtruong sorry, just want to hear your thoughts since Smithy is not my thing, BUT wouldn't use opensearch.openapi# already imply that those are vendor extensions for OpenAPI?

use opensearch.openapi#vendorExtensions

That would be pretty clean, no?

[harshavamsi]

@Xtansia @nhtruong for the sake of clarity could you explain why adding x- to the model for OpenAPI is required? Is this something OpenAPI codegen requires to understand namespaces?

[VachaShah]

Nice! Is this something we can document may be in this repo's developer guide?