Re-add handling of single value headers

core/response.go

@@ -103,8 +103,15 @@ func (r *ProxyResponseWriter) GetProxyResponse() (events.APIGatewayProxyResponse
 		isBase64 = true
 	}
 
+	proxyHeaders := make(map[string]string)
+
+	for h := range r.headers {
+		proxyHeaders[h] = r.headers.Get(h)
+	}
+
 	return events.APIGatewayProxyResponse{
 		StatusCode:        r.status,
+		Headers:         proxyHeaders,
 		MultiValueHeaders: http.Header(r.headers),
 		Body:              output,
 		IsBase64Encoded:   isBase64,

core/response_test.go

@@ -153,8 +153,8 @@ var _ = Describe("ResponseWriter tests", func() {
 			proxyResponse, err := response.GetProxyResponse()
 			Expect(err).To(BeNil())
 
-			// Headers are not written to `Headers` field
-			Expect(0).To(Equal(len(proxyResponse.Headers)))
+			// Headers are also written to `Headers` field
+			Expect(1).To(Equal(len(proxyResponse.Headers)))
 			Expect(1).To(Equal(len(proxyResponse.MultiValueHeaders["Content-Type"])))
 			Expect("application/json").To(Equal(proxyResponse.MultiValueHeaders["Content-Type"][0]))
 		})
@@ -167,8 +167,8 @@ var _ = Describe("ResponseWriter tests", func() {
 			proxyResponse, err := response.GetProxyResponse()
 			Expect(err).To(BeNil())
 
-			// Headers are not written to `Headers` field
-			Expect(0).To(Equal(len(proxyResponse.Headers)))
+			// Headers are also written to `Headers` field
+			Expect(2).To(Equal(len(proxyResponse.Headers)))
 
 			// There are two headers here because Content-Type is always written implicitly
 			Expect(2).To(Equal(len(proxyResponse.MultiValueHeaders["Set-Cookie"])))

go.mod

@@ -28,7 +28,7 @@ require (
 	github.com/json-iterator/go v0.0.0-20180128142709-bca911dae073
 	github.com/kardianos/govendor v1.0.9 // indirect
 	github.com/kataras/golog v0.0.0-20190624001437-99c81de45f40 // indirect
-	github.com/kataras/iris v11.1.1+incompatible // indirect
+	github.com/kataras/iris v11.1.1+incompatible
 	github.com/kataras/pio v0.0.0-20190103105442-ea782b38602d // indirect
 	github.com/klauspost/compress v1.7.4 // indirect
 	github.com/klauspost/cpuid v1.2.1 // indirect