feat: fallback invalid image (#172)

convert.go

@@ -81,7 +81,7 @@ func encode(src image.Image) (*bytes.Buffer, error) {
 }
 
 // Convert returns a image buffer converted to webp
-func Convert(src io.ReadCloser) (*bytes.Buffer, error) {
+func Convert(src io.Reader) (*bytes.Buffer, error) {
 	img, err := decode(src)
 	if err != nil {
 		return nil, err

transport.go

@@ -21,7 +21,9 @@
 package manael // import "manael.org/x/manael"
 
 import (
+	"bytes"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"log"
 	"net"
@@ -117,9 +119,16 @@ func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
 
 	defer resp.Body.Close()
 
-	buf, err := Convert(resp.Body)
+	var body io.Reader = resp.Body
+
+	p := bytes.NewBuffer(nil)
+	r := io.TeeReader(body, p)
+
+	buf, err := Convert(r)
 	if err != nil {
-		resp = NewResponse(req2, http.StatusInternalServerError)
+		body = io.MultiReader(p, body)
+
+		resp.Body = ioutil.NopCloser(body)
 		log.Printf("error: %v\n", err)
 
 		return resp, nil

transport_test.go

@@ -94,8 +94,8 @@ var transportTests = []struct {
 	{
 		"image/webp,image/*,*/*",
 		"/invalid.png",
-		http.StatusInternalServerError,
-		"text/plain; charset=utf-8",
+		http.StatusOK,
+		"image/png",
 		"not image",
 	},
 }