Extend OAS implementations

[eokoneyo]

Hi, following our discussion in https://github.com/IBM/openapi-to-graphql/pull/426 , I decided to open a different PR to tackle couple of issues I found pertaining to how the definitions from an OAS might be processed.

Here's a couple of issues the PR addresses;

• Fixes implementation where the style and explode properties for endpoint parameters didn't adhere to the Open API Spec. Given the partial definition;

  "/api/path": {
    get: {
     "parameters" : [ {
            "name" : "parameters",
            "in" : "query",
            "required" : true,
            "style" : "form",
            "explode" : true,
            "schema" : {
              "$ref" : "#/components/schemas/SomeSchemaInput"
            }
      } ],
    }
  }

  where SomeSchemaInput has properties of filter and limit for example, I found that the http request made for the generated GraphQL resolver is of the format; http://{baseUrl}/api/path?parameters[limit]=10&parameters[offset]=10 when the http request url should rather be http://{baseUrl}/api/path?limit=10&offset=10 considering the provided values for style and explode, as defined in Open API specification. Relates to https://github.com/IBM/openapi-to-graphql/pull/312 but also includes support for Arrays and Objects

• Also fix issue where an error is thrown when link is created with parameter that's a nested object; for instance given the link definition;

  ...
          responses: {
            200: {
              links: {
                invitations: {
                  operationId: 'someOperationId',
                  parameters: {
                    filter: {
                      entityId: '$response.body#/id',
                    },
                  },
                },
              },
            },
  

  previously filter would be attempted to be processed as a string, which resulted in errors.

[Alan-Cha]

@eokoneyo Thank you so much for the follow up! I will take a closer look at this later today and try to get it in. This is looking great so far!

[Alan-Cha]

Okay, I have reviewed this and I generally like what I see! I have a few comments, however, which I will try to address. All in all, I think we can merge this in!

[Alan-Cha]

@eokoneyo It's in! Thanks so much again! I know this fix and the old PR has been getting really stale. This was a really great change! Thank you once again!