httpmock responder that cycles through a list of responses

responder.go

import (
  "net/http"
  
  "github.com/jarcoal/httpmock"
)

func NewChainResponder(responders []httpmock.Responder) httpmock.Responder {
	cursor := 0

	return func(req *http.Request) (*http.Response, error) {
		if len(responders) == 0 {
			return nil, httpmock.NoResponderFound
		}
		next := responders[cursor]
		cursor++
		if cursor >= len(responders) {
			cursor = 0
		}

		return next(req)
	}
}

// ...

// Register a responder that responds differently to subsequent requests to the same URL
httpmock.RegisterResponder(
	"GET",
	baseURL + "/foo",
	NewChainResponder([]httpmock.Responder{
		httpmock.NewStringResponder(200, `[]`),
		httpmock.NewStringResponder(500, ``),
		httpmock.NewStringResponder(200, `[{"id": 1, "name": "bar"}]`),
	}))