Support for conditionally dereferencing with getReference/findReference class methods

[huypham50]

My current logic looks like this

const oasNormalizer = new OASNormalize(url)
const validatedSchema = await oasNormalizer.validate()
const schema = new Oas(validatedSchema);
await schema.dereference()

// skipping some traverse logic

let reqBodySchema: MediaTypeObject['schema'] = undefined
if (reqBodySchema) {
  if ('type' in reqBodySchema) {
    console.log('type:', reqBodySchema.type)
  } else if ('$ref' in reqBodySchema) { // we should not need to do this because the schema has been dereferenced
    console.log('ref:', reqBodySchema.$ref)
  }
}

At this point, since the schema has been dereferenced, should we narrow the types so we don't have to do type narrowing? Something like this:

// dereferencedSchema returns a narrower type of schema that removes RefObject from `X | RefObject`
const dereferencedSchema = await schema.dereference()

Also, is there a way conditionally dereference schema? Something like this:

if ('$ref' in reqBodySchema) {
  const ref = reqBodySchema.$ref // ref is a string
  const refSchema1 = schema.getReference(ref) // return schema or throw error
  const refSchema2 = schema.findReference(ref) // return schema or undefined
}

Let me know if I am doing anything that is not standard. New to this (great) library. Also recommendations for great Typescript libraries for the OpenAPI / JSONSchema ecosystem would be greatly appreciated!

[erunion]

This is tricky because technically after dereferencing $ref may still be present if there was a circular reference present. I'm definitely not opposed to adding some getReference and findReference tooling into oas core. If you're interested in doing that work we'd happily pull it in.