Fix for taking screencast

Author: int128

.gitignore

@@ -1 +1,3 @@
 /.idea
+
+/example/example

example/main.go

@@ -6,6 +6,7 @@ import (
 	"os"
 
 	"github.com/int128/oauth2cli"
+	"github.com/pkg/browser"
 	"golang.org/x/oauth2"
 	"golang.org/x/oauth2/google"
 	"golang.org/x/sync/errgroup"
@@ -16,7 +17,11 @@ func main() {
 	ctx := context.Background()
 	clientID, clientSecret := os.Getenv("GOOGLE_CLIENT_ID"), os.Getenv("GOOGLE_CLIENT_SECRET")
 	if clientID == "" || clientSecret == "" {
-		log.Fatalf("You need to set GOOGLE_CLIENT_ID and GOOGLE_CLIENT_SECRET")
+		log.Fatalf(`You need to set oauth2 credentials.
+Open https://console.cloud.google.com/apis/credentials and create a client. And then,
+export GOOGLE_CLIENT_ID=xxx.apps.googleusercontent.com
+export GOOGLE_CLIENT_SECRET=xxx
+`)
 	}
 
 	ready := make(chan string, 1)
@@ -28,7 +33,9 @@ func main() {
 				return nil
 			}
 			log.Printf("Open %s", url)
-			// you can open the browser here
+			if err := browser.OpenURL(url); err != nil {
+				log.Printf("could not open the browser: %s", err)
+			}
 			return nil
 		case err := <-ctx.Done():
 			return xerrors.Errorf("context done while waiting for authorization: %w", err)
@@ -48,8 +55,7 @@ func main() {
 		if err != nil {
 			return xerrors.Errorf("could not get a token: %w", err)
 		}
-		log.Printf("Got a token: %+v", token)
-		log.Printf("Your token is valid until %s", token.Expiry)
+		log.Printf("You got a valid token until %s", token.Expiry)
 		return nil
 	})
 	if err := eg.Wait(); err != nil {

go.mod

@@ -1,6 +1,7 @@
 module github.com/int128/oauth2cli
 
 require (
+	github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4
 	golang.org/x/oauth2 v0.0.0-20190319182350-c85d3e98c914
 	golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4
 	golang.org/x/xerrors v0.0.0-20190513163551-3ee3066db522

go.sum

@@ -2,6 +2,8 @@ cloud.google.com/go v0.34.0 h1:eOI3/cP2VTU6uZLDYAoic+eyzzB9YyGmJ7eIjl8rOPg=
 cloud.google.com/go v0.34.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4 h1:49lOXmGaUpV9Fz3gd7TFZY106KVlPVa5jcYD1gaQf98=
+github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4/go.mod h1:4OwLy04Bl9Ef3GJJCoec+30X3LQs/0/m4HFRt/2LUSA=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190108225652-1e06a53dbb7e h1:bRhVy7zSSasaqNksaRZiA5EEI+Ei4I1nO5Jh72wfHlg=
 golang.org/x/net v0.0.0-20190108225652-1e06a53dbb7e/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=