Generated render/bind implementations

[zacharyburkett]

Currently we use https://github.com/go-chi/render interfaces for our generated types, simplifying request/response management.

I propose we implement our own alternative that is generated alongside server/type code.

A generated implementation removes the need for a dependency and allows us to easily modify it to suit any future needs (ie more content types).

[dustin-decker]

Closed by #47 ?

[karitham]

Not exactly,

This issue is about generating go-chi/render's functions directly alongside the generated code, avoiding the dependency.

Since we already generate the implementation of interfaces, we just need the actual render implementation, which is quite small

[zacharyburkett]

Correct, the goal of this issue is to simplify our dependencies.

[diamondburned]

As a sidenote, I think we're better off changing the generated method signatures to return a *Response or (*Response, error) pair directly instead of having the user call the Render function, since we're already breaking the http.Handler signature. For example,

func (h handler) Login(w http.ResponseWriter, r *http.Request, params openapi.LoginParams) *openapi.Response {
	s, err := h.server.LoginServer().Login(
		r.Context(),
		params.Username, params.Password,
		foodtinder.LoginMetadata{
			UserAgent: r.Header.Get("User-Agent"),
		},
	)
	if err != nil {
		return openapi.LoginJSON400Response(openapi.Error{Error: err})
	}

	return openapi.LoginJSON200Response(openapi.Session{
		UserID: openapi.ID(s.UserID),
		Token:  s.Token,
		Expiry: s.Expiry,
		Metadata: openapi.LoginMetadata{
			UserAgent: optstr(s.Metadata.UserAgent),
		},
	})
}

(package openapi is autogenerated.)

Created PR #80 to implement this.