From f6e1a2df92640371f70d01ef6a1e80a15d8358c8 Mon Sep 17 00:00:00 2001
From: Austin Riendeau <austin@apriendeau.com>
Date: Sun, 25 Oct 2015 19:58:53 -0600
Subject: [PATCH] [silence-errors]: -m adds a way for errors to silenced down
 the stack

---
 cobra_test.go | 46 ++++++++++++++++++++++++++++++++--------------
 command.go    | 22 ++++++++++++++--------
 2 files changed, 46 insertions(+), 22 deletions(-)

diff --git a/cobra_test.go b/cobra_test.go
index f4814ea..66e44e4 100644
--- a/cobra_test.go
+++ b/cobra_test.go
@@ -217,6 +217,12 @@ func fullSetupTest(input string) resulter {
 	return fullTester(c, input)
 }
 
+func noRRSetupTestSilenced(input string) resulter {
+	c := initialize()
+	c.SilenceErrors = true
+	return fullTester(c, input)
+}
+
 func noRRSetupTest(input string) resulter {
 	c := initialize()
 
@@ -488,8 +494,8 @@ func TestChildCommandFlags(t *testing.T) {
 		t.Errorf("invalid flag should generate error")
 	}
 
-	if !strings.Contains(r.Output, "unknown shorthand") {
-		t.Errorf("Wrong error message displayed, \n %s", r.Output)
+	if !strings.Contains(r.Error.Error(), "unknown shorthand") {
+		t.Errorf("Wrong error message displayed, \n %s", r.Error)
 	}
 
 	if flagi2 != 99 {
@@ -506,9 +512,8 @@ func TestChildCommandFlags(t *testing.T) {
 	if r.Error == nil {
 		t.Errorf("invalid flag should generate error")
 	}
-
-	if !strings.Contains(r.Output, "unknown shorthand flag") {
-		t.Errorf("Wrong error message displayed, \n %s", r.Output)
+	if !strings.Contains(r.Error.Error(), "unknown shorthand flag") {
+		t.Errorf("Wrong error message displayed, \n %s", r.Error)
 	}
 
 	// Testing with persistent flag overwritten by child
@@ -528,9 +533,8 @@ func TestChildCommandFlags(t *testing.T) {
 	if r.Error == nil {
 		t.Errorf("invalid input should generate error")
 	}
-
-	if !strings.Contains(r.Output, "invalid argument \"10E\" for i10E") {
-		t.Errorf("Wrong error message displayed, \n %s", r.Output)
+	if !strings.Contains(r.Error.Error(), "invalid argument \"10E\" for i10E") {
+		t.Errorf("Wrong error message displayed, \n %s", r.Error)
 	}
 }
 
@@ -547,10 +551,10 @@ func TestInvalidSubcommandFlags(t *testing.T) {
 	cmd.AddCommand(cmdTimes)
 
 	result := simpleTester(cmd, "times --inttwo=2 --badflag=bar")
-
-	checkResultContains(t, result, "unknown flag: --badflag")
-
-	if strings.Contains(result.Output, "unknown flag: --inttwo") {
+	// given that we are not checking here result.Error we check for
+	// stock usage message
+	checkResultContains(t, result, "cobra-test times [# times]")
+	if strings.Contains(result.Error.Error(), "unknown flag: --inttwo") {
 		t.Errorf("invalid --badflag flag shouldn't fail on 'unknown' --inttwo flag")
 	}
 
@@ -809,6 +813,20 @@ func TestRootUnknownCommand(t *testing.T) {
 	}
 }
 
+func TestRootUnknownCommandSilenced(t *testing.T) {
+	r := noRRSetupTestSilenced("bogus")
+	s := "Run 'cobra-test --help' for usage.\n"
+
+	if r.Output != "" {
+		t.Errorf("Unexpected response.\nExpecting to be: \n\"\"\n Got:\n %q\n", s, r.Output)
+	}
+
+	r = noRRSetupTestSilenced("--strtwo=a bogus")
+	if r.Output != "" {
+		t.Errorf("Unexpected response.\nExpecting to be:\n\"\"\nGot:\n %q\n", s, r.Output)
+	}
+}
+
 func TestRootSuggestions(t *testing.T) {
 	outputWithSuggestions := "Error: unknown command \"%s\" for \"cobra-test\"\n\nDid you mean this?\n\t%s\n\nRun 'cobra-test --help' for usage.\n"
 	outputWithoutSuggestions := "Error: unknown command \"%s\" for \"cobra-test\"\nRun 'cobra-test --help' for usage.\n"
@@ -872,8 +890,8 @@ func TestFlagsBeforeCommand(t *testing.T) {
 
 	// With parsing error properly reported
 	x = fullSetupTest("-i10E echo")
-	if !strings.Contains(x.Output, "invalid argument \"10E\" for i10E") {
-		t.Errorf("Wrong error message displayed, \n %s", x.Output)
+	if !strings.Contains(x.Error.Error(), "invalid argument \"10E\" for i10E") {
+		t.Errorf("Wrong error message displayed, \n %s", x.Error)
 	}
 
 	//With quotes
diff --git a/command.go b/command.go
index 2041243..89854cb 100644
--- a/command.go
+++ b/command.go
@@ -61,6 +61,8 @@ type Command struct {
 	pflags *flag.FlagSet
 	// Flags that are declared specifically by this command (not inherited).
 	lflags *flag.FlagSet
+	// SilenceErrors is an option to quiet errors down stream
+	SilenceErrors bool
 	// The *Run functions are executed in the following order:
 	//   * PersistentPreRun()
 	//   * PreRun()
@@ -626,21 +628,25 @@ func (c *Command) Execute() (err error) {
 		if cmd != nil {
 			c = cmd
 		}
-		c.Println("Error:", err.Error())
-		c.Printf("Run '%v --help' for usage.\n", c.CommandPath())
+		if !c.SilenceErrors {
+			c.Println("Error:", err.Error())
+			c.Printf("Run '%v --help' for usage.\n", c.CommandPath())
+		}
 		return err
 	}
 
 	err = cmd.execute(flags)
 	if err != nil {
-		if err == flag.ErrHelp {
-			cmd.HelpFunc()(cmd, args)
-			return nil
+		if !cmd.SilenceErrors {
+			if err == flag.ErrHelp {
+				cmd.HelpFunc()(cmd, args)
+				return nil
+			}
+			c.Println(cmd.UsageString())
+			c.Println("Error:", err.Error())
 		}
-		c.Println(cmd.UsageString())
-		c.Println("Error:", err.Error())
+		return err
 	}
-
 	return
 }