fix: handle invalid image (#167)

response.go

@@ -0,0 +1,50 @@
+// Copyright (c) 2019 Yamagishi Kazutoshi <[email protected]>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+// Package manael provides HTTP handler for processing images.
+package manael // import "manael.org/x/manael"
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+)
+
+// NewResponse returns response
+func NewResponse(r *http.Request, status int) *http.Response {
+	header := make(http.Header)
+	statusText := http.StatusText(status)
+
+	body := fmt.Sprintf("%d %s", status, statusText)
+	buf := bytes.NewBufferString(body)
+
+	header.Set("Content-Type", "text/plain; charset=utf-8")
+
+	return &http.Response{
+		Status:           statusText,
+		StatusCode:       status,
+		Header:           header,
+		Body:             ioutil.NopCloser(buf),
+		ContentLength:    int64(buf.Len()),
+		Request:          r,
+		TransferEncoding: r.TransferEncoding,
+	}
+}

response_test.go

@@ -0,0 +1,86 @@
+// Copyright (c) 2019 Yamagishi Kazutoshi <[email protected]>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package manael_test // import "manael.org/x/manael"
+
+import (
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"manael.org/x/manael"
+)
+
+var responseTests = []struct {
+	statusCode    int
+	status        string
+	contentLength int64
+	body          string
+}{
+	{
+		http.StatusOK,
+		"OK",
+		6,
+		"200 OK",
+	},
+	{
+		http.StatusNotFound,
+		"Not Found",
+		13,
+		"404 Not Found",
+	},
+	{
+		http.StatusInternalServerError,
+		"Internal Server Error",
+		25,
+		"500 Internal Server Error",
+	},
+}
+
+func TestNewResponse(t *testing.T) {
+	for _, tc := range responseTests {
+		req := httptest.NewRequest(http.MethodGet, "https://manael.test/", nil)
+
+		resp := manael.NewResponse(req, tc.statusCode)
+		defer resp.Body.Close()
+
+		if got, want := resp.StatusCode, tc.statusCode; got != want {
+			t.Errorf("Status code is %d, want %d", got, want)
+		}
+
+		if got, want := resp.Status, tc.status; got != want {
+			t.Errorf("Status is %s, want %s", got, want)
+		}
+
+		if got, want := resp.ContentLength, tc.contentLength; got != want {
+			t.Errorf("Content length is %d, want %d", got, want)
+		}
+
+		body, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if got, want := string(body), tc.body; got != want {
+			t.Errorf("Response body is %s, want %s", got, want)
+		}
+	}
+}

transport.go

@@ -24,6 +24,7 @@ package manael // import "manael.org/x/manael"
 import (
 	"fmt"
 	"io/ioutil"
+	"log"
 	"net"
 	"net/http"
 	"net/url"
@@ -119,7 +120,10 @@ func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
 
 	buf, err := convert(resp.Body)
 	if err != nil {
-		return nil, err
+		resp = NewResponse(req2, http.StatusInternalServerError)
+		log.Printf("error: %v\n", err)
+
+		return resp, nil
 	}
 
 	resp.Body = ioutil.NopCloser(buf)

transport_test.go

@@ -91,6 +91,13 @@ var transportTests = []struct {
 		"text/plain; charset=utf-8",
 		"not image",
 	},
+	{
+		"image/webp,image/*,*/*",
+		"/invalid.png",
+		http.StatusInternalServerError,
+		"text/plain; charset=utf-8",
+		"not image",
+	},
 }
 
 func TestTransport_RoundTrip(t *testing.T) {
@@ -107,6 +114,9 @@ func TestTransport_RoundTrip(t *testing.T) {
 	mux.HandleFunc("/empty.txt", func(w http.ResponseWriter, r *http.Request) {
 		http.ServeFile(w, r, "testdata/empty.txt")
 	})
+	mux.HandleFunc("/invalid.png", func(w http.ResponseWriter, r *http.Request) {
+		http.ServeFile(w, r, "testdata/invalid.png")
+	})
 
 	ts := httptest.NewServer(mux)
 	defer ts.Close()
@@ -398,7 +408,7 @@ func TestTransport_RoundTrip_noTransform(t *testing.T) {
 
 var transportTests6 = []struct {
 	path string
-	xff string
+	xff  string
 }{
 	{
 		"/xff.txt",
@@ -441,4 +451,4 @@ func TestTransport_RoundTrip_xForwardedFor(t *testing.T) {
 			t.Errorf(`X-Forwarded-For is "%s", want "%s"`, got, want)
 		}
 	}
-}
+}