From a6e61a3a8d49eaa720906f7023fef7d11e56af6e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mislav=20Marohni=C4=87?= <mislav@github.com>
Date: Thu, 31 Oct 2019 13:21:22 +0100
Subject: [PATCH 1/3] Silence Cobra usage on errors

When an error occurs anywhere in a command, Cobra used to print the
error itself and command usage help.

We already print error in `main()`, and we don't want to use command
usage string on anything other than flag-parsing errors.

This also fixes the double output of each error.
---
 command/root.go | 16 ++++++++++++----
 main.go         |  4 +++-
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/command/root.go b/command/root.go
index c0b676c86..51c602511 100644
--- a/command/root.go
+++ b/command/root.go
@@ -1,6 +1,7 @@
 package command
 
 import (
+	"errors"
 	"fmt"
 	"os"
 
@@ -16,17 +17,24 @@ func init() {
 	RootCmd.PersistentFlags().StringP("current-branch", "B", "", "current git branch")
 	// TODO:
 	// RootCmd.PersistentFlags().BoolP("verbose", "V", false, "enable verbose output")
+
+	RootCmd.SetFlagErrorFunc(func(cmd *cobra.Command, err error) error {
+		cmd.Println(err)
+		cmd.Println(cmd.UsageString())
+		return SilentErr
+	})
 }
 
+var SilentErr = errors.New("SilentErr")
+
 // RootCmd is the entry point of command-line execution
 var RootCmd = &cobra.Command{
 	Use:   "gh",
 	Short: "GitHub CLI",
 	Long:  `Do things with GitHub from your terminal`,
-	Args:  cobra.MinimumNArgs(1),
-	Run: func(cmd *cobra.Command, args []string) {
-		fmt.Println("root")
-	},
+
+	SilenceErrors: true,
+	SilenceUsage:  true,
 }
 
 // overriden in tests
diff --git a/main.go b/main.go
index f954ae933..2ef3e1e2c 100644
--- a/main.go
+++ b/main.go
@@ -9,7 +9,9 @@ import (
 
 func main() {
 	if err := command.RootCmd.Execute(); err != nil {
-		fmt.Println(err)
+		if err != command.SilentErr {
+			fmt.Println(err)
+		}
 		os.Exit(1)
 	}
 }

From faa96be9eadd3fe5d9f4b23637322946ddbb2fea Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mislav=20Marohni=C4=87?= <mislav@github.com>
Date: Thu, 31 Oct 2019 15:46:38 +0100
Subject: [PATCH 2/3] Ensure that errors are printed to stderr

---
 main.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/main.go b/main.go
index 2ef3e1e2c..ae20c309d 100644
--- a/main.go
+++ b/main.go
@@ -10,7 +10,7 @@ import (
 func main() {
 	if err := command.RootCmd.Execute(); err != nil {
 		if err != command.SilentErr {
-			fmt.Println(err)
+			fmt.Fprintln(os.Stderr, err)
 		}
 		os.Exit(1)
 	}

From e87775845d3e19548448acc6f26692ffce11998c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mislav=20Marohni=C4=87?= <mislav@github.com>
Date: Thu, 31 Oct 2019 22:44:43 +0100
Subject: [PATCH 3/3] Also print cmd usage string on "unknown command"

---
 command/root.go | 10 +++++-----
 main.go         |  9 ++++++---
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/command/root.go b/command/root.go
index 51c602511..a309960e3 100644
--- a/command/root.go
+++ b/command/root.go
@@ -1,7 +1,6 @@
 package command
 
 import (
-	"errors"
 	"fmt"
 	"os"
 
@@ -19,13 +18,14 @@ func init() {
 	// RootCmd.PersistentFlags().BoolP("verbose", "V", false, "enable verbose output")
 
 	RootCmd.SetFlagErrorFunc(func(cmd *cobra.Command, err error) error {
-		cmd.Println(err)
-		cmd.Println(cmd.UsageString())
-		return SilentErr
+		return FlagError{err}
 	})
 }
 
-var SilentErr = errors.New("SilentErr")
+// FlagError is the kind of error raised in flag processing
+type FlagError struct {
+	error
+}
 
 // RootCmd is the entry point of command-line execution
 var RootCmd = &cobra.Command{
diff --git a/main.go b/main.go
index ae20c309d..e7f94a5d0 100644
--- a/main.go
+++ b/main.go
@@ -3,14 +3,17 @@ package main
 import (
 	"fmt"
 	"os"
+	"strings"
 
 	"github.com/github/gh-cli/command"
 )
 
 func main() {
-	if err := command.RootCmd.Execute(); err != nil {
-		if err != command.SilentErr {
-			fmt.Fprintln(os.Stderr, err)
+	if cmd, err := command.RootCmd.ExecuteC(); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		_, isFlagError := err.(command.FlagError)
+		if isFlagError || strings.HasPrefix(err.Error(), "unknown command ") {
+			fmt.Fprintln(os.Stderr, cmd.UsageString())
 		}
 		os.Exit(1)
 	}