Closes elysiajs/elysia#1825

Problem

Routes using parse: "arrayBuffer" with a body schema produced an OpenAPI request body with an empty content object:

{
  "requestBody": {
    "content": {}
  }
}

That makes OpenAPI clients infer the request body as missing or undefined.

Fix

Map arrayBuffer request parsers to application/octet-stream when generating request body content. The same mapping is also used when the parser is already declared as application/octet-stream.

Tests

Added a regression in test/openapi/to-openapi-schema.test.ts for:

• parse: "arrayBuffer"
• binary body schema description
• generated requestBody.content["application/octet-stream"]

Verification run:

• bun test test/openapi/to-openapi-schema.test.ts
• git diff --check
• bun run build
• PATH="$PWD/node_modules/.bin:$PATH" bun run test

Summary by CodeRabbit

• New Features

  • Added support for binary request payloads in OpenAPI schema generation. Binary data is now properly documented with application/octet-stream content type, enabling accurate API documentation for endpoints that accept binary data.

• Tests

  • Added test coverage for binary request payload handling in OpenAPI conversion.