get header middleware

Author: talpert

middleware_getheader.go

@@ -0,0 +1,40 @@
+package rye
+
+import (
+	"context"
+	"net/http"
+)
+
+type getHeader struct {
+	headerName string
+	contextKey string
+}
+
+/*
+NewMiddlewareGetHeader creates a new handler to extract any header and save its value into the context.
+	headerName: the name of the header you want to extract
+	contextKey: the value key that you would like to store this header under in the context
+
+Example usage:
+
+	routes.Handle("/some/route", a.Dependencies.MWHandler.Handle(
+		[]rye.Handler{
+			rye.NewMiddlewareGetHeader(headerName, contextKey),
+			yourHandler,
+		})).Methods("POST")
+*/
+func NewMiddlewareGetHeader(headerName, contextKey string) func(rw http.ResponseWriter, req *http.Request) *Response {
+	h := getHeader{headerName: headerName, contextKey: contextKey}
+	return h.getHeaderMiddleware
+}
+
+func (h *getHeader) getHeaderMiddleware(rw http.ResponseWriter, r *http.Request) *Response {
+	rID := r.Header.Get(h.headerName)
+	if rID != "" {
+		return &Response{
+			Context: context.WithValue(r.Context(), h.contextKey, rID),
+		}
+	}
+
+	return nil
+}

middleware_getheader_test.go

@@ -0,0 +1,44 @@
+package rye
+
+import (
+	"net/http"
+	"net/http/httptest"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Get Header Middleware", func() {
+	var (
+		request  *http.Request
+		response *httptest.ResponseRecorder
+	)
+
+	BeforeEach(func() {
+		response = httptest.NewRecorder()
+		request = &http.Request{
+			Header: make(map[string][]string, 0),
+		}
+	})
+
+	Describe("getHeaderMiddleware", func() {
+		Context("when a valid header is passed", func() {
+			It("should return context with value", func() {
+				headerName := "SpecialHeader"
+				ctxKey := "special"
+				request.Header.Add(headerName, "secret value")
+				resp := NewMiddlewareGetHeader(headerName, ctxKey)(response, request)
+				Expect(resp).ToNot(BeNil())
+				Expect(resp.Context).ToNot(BeNil())
+				Expect(resp.Context.Value(ctxKey)).To(Equal("secret value"))
+			})
+		})
+
+		Context("when no header is passed", func() {
+			It("should have no value in context", func() {
+				resp := NewMiddlewareGetHeader("something", "not there")(response, request)
+				Expect(resp).To(BeNil())
+			})
+		})
+	})
+})