From 853fda13e987f7eb3f1239cf7f78f8fa30daa66b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mislav=20Marohni=C4=87?= <mislav@github.com>
Date: Mon, 13 Jan 2020 20:31:31 +0100
Subject: [PATCH] Add more OAuth flow debugging to stderr with `DEBUG=oauth`

---
 auth/oauth.go           | 15 ++++++++++++++-
 context/config_setup.go |  7 +++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/auth/oauth.go b/auth/oauth.go
index 5a09b9c1c..b2b199b48 100644
--- a/auth/oauth.go
+++ b/auth/oauth.go
@@ -30,6 +30,7 @@ type OAuthFlow struct {
 	ClientID         string
 	ClientSecret     string
 	WriteSuccessHTML func(io.Writer)
+	VerboseStream    io.Writer
 }
 
 // ObtainAccessToken guides the user through the browser OAuth flow on GitHub
@@ -52,12 +53,14 @@ func (oa *OAuthFlow) ObtainAccessToken() (accessToken string, err error) {
 	q.Set("state", state)
 
 	startURL := fmt.Sprintf("https://%s/login/oauth/authorize?%s", oa.Hostname, q.Encode())
+	oa.logf("open %s\n", startURL)
 	if err := openInBrowser(startURL); err != nil {
 		fmt.Fprintf(os.Stderr, "error opening web browser: %s\n", err)
 		fmt.Fprintf(os.Stderr, "Please open the following URL manually:\n%s\n", startURL)
 	}
 
 	http.Serve(listener, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		oa.logf("server handler: %s\n", r.URL.Path)
 		if r.URL.Path != "/callback" {
 			w.WriteHeader(404)
 			return
@@ -69,6 +72,7 @@ func (oa *OAuthFlow) ObtainAccessToken() (accessToken string, err error) {
 			return
 		}
 		code = rq.Get("code")
+		oa.logf("server received code %q\n", code)
 		w.Header().Add("content-type", "text/html")
 		if oa.WriteSuccessHTML != nil {
 			oa.WriteSuccessHTML(w)
@@ -77,7 +81,9 @@ func (oa *OAuthFlow) ObtainAccessToken() (accessToken string, err error) {
 		}
 	}))
 
-	resp, err := http.PostForm(fmt.Sprintf("https://%s/login/oauth/access_token", oa.Hostname),
+	tokenURL := fmt.Sprintf("https://%s/login/oauth/access_token", oa.Hostname)
+	oa.logf("POST %s\n", tokenURL)
+	resp, err := http.PostForm(tokenURL,
 		url.Values{
 			"client_id":     {oa.ClientID},
 			"client_secret": {oa.ClientSecret},
@@ -109,6 +115,13 @@ func (oa *OAuthFlow) ObtainAccessToken() (accessToken string, err error) {
 	return
 }
 
+func (oa *OAuthFlow) logf(format string, args ...interface{}) {
+	if oa.VerboseStream == nil {
+		return
+	}
+	fmt.Fprintf(oa.VerboseStream, format, args...)
+}
+
 func openInBrowser(url string) error {
 	var args []string
 	switch runtime.GOOS {
diff --git a/context/config_setup.go b/context/config_setup.go
index 48a037a24..d65ffb888 100644
--- a/context/config_setup.go
+++ b/context/config_setup.go
@@ -6,6 +6,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/github/gh-cli/api"
 	"github.com/github/gh-cli/auth"
@@ -26,6 +27,11 @@ var (
 // TODO: have a conversation about whether this belongs in the "context" package
 // FIXME: make testable
 func setupConfigFile(filename string) (*configEntry, error) {
+	var verboseStream io.Writer
+	if strings.Contains(os.Getenv("DEBUG"), "oauth") {
+		verboseStream = os.Stderr
+	}
+
 	flow := &auth.OAuthFlow{
 		Hostname:     oauthHost,
 		ClientID:     oauthClientID,
@@ -33,6 +39,7 @@ func setupConfigFile(filename string) (*configEntry, error) {
 		WriteSuccessHTML: func(w io.Writer) {
 			fmt.Fprintln(w, oauthSuccessPage)
 		},
+		VerboseStream: verboseStream,
 	}
 
 	fmt.Fprintln(os.Stderr, "Notice: authentication required")