Fix Google App Engine support and provide working example

example/appengine/app.go

@@ -0,0 +1,48 @@
+// Copyright 2017 The go-github AUTHORS. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The demo app shows how to use the github package on Google App Engine.
+package demo
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+
+	"github.com/google/go-github/github"
+	"golang.org/x/oauth2"
+	"google.golang.org/appengine"
+	"google.golang.org/appengine/log"
+)
+
+func init() {
+	http.HandleFunc("/", handler)
+}
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path != "/" {
+		http.NotFound(w, r)
+		return
+	}
+
+	ctx := appengine.NewContext(r)
+	ts := oauth2.StaticTokenSource(
+		&oauth2.Token{AccessToken: os.Getenv("GITHUB_AUTH_TOKEN")},
+	)
+	tc := oauth2.NewClient(ctx, ts)
+	client := github.NewClient(tc)
+
+	commits, _, err := client.Repositories.ListCommits(ctx, "google", "go-github", nil)
+	if err != nil {
+		log.Errorf(ctx, "ListCommits: %v", err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	for _, commit := range commits {
+		fmt.Fprintln(w, commit.GetHTMLURL())
+	}
+}

example/appengine/app.yaml

@@ -0,0 +1,14 @@
+# Copyright 2017 The go-github AUTHORS. All rights reserved.
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+runtime: go
+api_version: go1
+
+handlers:
+- url: /.*
+  script: _go_app
+
+env_variables:
+  GITHUB_AUTH_TOKEN: "-your-auth-token-here-"

github/github.go

@@ -399,7 +399,7 @@ func parseRate(r *http.Response) Rate {
 // The provided ctx must be non-nil. If it is canceled or times out,
 // ctx.Err() will be returned.
 func (c *Client) Do(ctx context.Context, req *http.Request, v interface{}) (*Response, error) {
-	ctx, req = withContext(ctx, req)
+	req = withContext(ctx, req)
 
 	rateLimitCategory := category(req.URL.Path)
 

github/repos_contents.go

@@ -248,7 +248,7 @@ func (s *RepositoriesService) GetArchiveLink(ctx context.Context, owner, repo st
 	}
 	var resp *http.Response
 	// Use http.DefaultTransport if no custom Transport is configured
-	ctx, req = withContext(ctx, req)
+	req = withContext(ctx, req)
 	if s.client.client.Transport == nil {
 		resp, err = http.DefaultTransport.RoundTrip(req)
 	} else {

github/repos_releases.go

@@ -244,7 +244,7 @@ func (s *RepositoriesService) DownloadReleaseAsset(ctx context.Context, owner, r
 	}
 	defer func() { s.client.client.CheckRedirect = saveRedirect }()
 
-	ctx, req = withContext(ctx, req)
+	req = withContext(ctx, req)
 	resp, err := s.client.client.Do(req)
 	if err != nil {
 		if !strings.Contains(err.Error(), "disable redirect") {

github/with_appengine.go

@@ -17,10 +17,9 @@ package github
 import (
 	"context"
 	"net/http"
-
-	"google.golang.org/appengine"
 )
 
-func withContext(ctx context.Context, req *http.Request) (context.Context, *http.Request) {
-	return appengine.WithContext(ctx, req), req
+func withContext(ctx context.Context, req *http.Request) *http.Request {
+	// No-op because App Engine adds context to a request differently.
+	return req
 }

github/without_appengine.go

@@ -14,6 +14,6 @@ import (
 	"net/http"
 )
 
-func withContext(ctx context.Context, req *http.Request) (context.Context, *http.Request) {
-	return ctx, req.WithContext(ctx)
+func withContext(ctx context.Context, req *http.Request) *http.Request {
+	return req.WithContext(ctx)
 }