Merge pull request #41 from github/silence-usage

Silence Cobra usage on errors

command/root.go

@@ -16,6 +16,15 @@ 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 {
+		return FlagError{err}
+	})
+}
+
+// FlagError is the kind of error raised in flag processing
+type FlagError struct {
+	error
 }
 
 // RootCmd is the entry point of command-line execution
@@ -23,10 +32,9 @@ 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

main.go

@@ -3,13 +3,18 @@ package main
 import (
 	"fmt"
 	"os"
+	"strings"
 
 	"github.com/github/gh-cli/command"
 )
 
 func main() {
-	if err := command.RootCmd.Execute(); err != nil {
-		fmt.Println(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)
 	}
 }