Adding support for --help

README.md

@@ -298,11 +298,11 @@ embeds the usage as part of it's output.
       hugo [command]
 
     Available Commands:
-      server          :: Hugo runs it's own a webserver to render the files
-      version         :: Print the version number of Hugo
-      check           :: Check content in the source directory
-      benchmark       :: Benchmark hugo by building a site a number of times
-      help [command]  :: Help about any command
+      server          Hugo runs it's own a webserver to render the files
+      version         Print the version number of Hugo
+      check           Check content in the source directory
+      benchmark       Benchmark hugo by building a site a number of times
+      help [command]  Help about any command
 
      Available Flags:
       -b, --base-url="": hostname (and path) to the root eg. http://spf13.com/

cobra_test.go

@@ -114,11 +114,49 @@ func initializeWithRootCmd() *Command {
 	tt, tp, te, rootcalled = nil, nil, nil, false
 	flagInit()
 	cmdRootWithRun.Flags().BoolVarP(&flagbr, "boolroot", "b", false, "help message for flag boolroot")
-	cmdRootWithRun.Flags().IntVarP(&flagir, "introot", "i", 321, "help message for flag intthree")
+	cmdRootWithRun.Flags().IntVarP(&flagir, "introot", "i", 321, "help message for flag introot")
 	commandInit()
 	return cmdRootWithRun
 }
 
+type resulter struct {
+	Error   error
+	Output  string
+	Command *Command
+}
+
+func fullSetupTest(input string) resulter {
+	c := initializeWithRootCmd()
+
+	return fullTester(c, input)
+}
+
+func noRRSetupTest(input string) resulter {
+	c := initialize()
+
+	return fullTester(c, input)
+}
+
+func fullTester(c *Command, input string) resulter {
+	buf := new(bytes.Buffer)
+	// Testing flag with invalid input
+	c.SetOutput(buf)
+	cmdEcho.AddCommand(cmdTimes)
+	c.AddCommand(cmdPrint, cmdEcho)
+	c.SetArgs(strings.Split(input, " "))
+
+	err := c.Execute()
+	output := buf.String()
+
+	return resulter{err, output, c}
+}
+
+func checkResultContains(t *testing.T, x resulter, check string) {
+	if !strings.Contains(x.Output, check) {
+		t.Errorf("Unexpected response.\nExpecting to contain: \n %q\nGot:\n %q\n", check, x.Output)
+	}
+}
+
 func checkOutputContains(t *testing.T, c *Command, check string) {
 	buf := new(bytes.Buffer)
 	c.SetOutput(buf)
@@ -448,12 +486,23 @@ func TestRootFlags(t *testing.T) {
 }
 
 func TestRootHelp(t *testing.T) {
-	fmt.Println("testing root help")
-	c := initializeWithRootCmd()
-	c.AddCommand(cmdPrint, cmdEcho)
-	c.SetArgs(strings.Split("--help", " "))
-	e := c.Execute()
-	fmt.Println(e)
+	x := fullSetupTest("--help")
+
+	checkResultContains(t, x, "Available Commands:")
+
+	if strings.Contains(x.Output, "unknown flag: --help") {
+		t.Errorf("--help shouldn't trigger an error, Got: \n %s", x.Output)
+	}
+
+	x = fullSetupTest("echo --help")
+
+	checkResultContains(t, x, "Available Commands:")
+
+	if strings.Contains(x.Output, "unknown flag: --help") {
+		t.Errorf("--help shouldn't trigger an error, Got: \n %s", x.Output)
+	}
+
+}
 
 	checkOutputContains(t, c, "Available Commands:")
 }

command.go

@@ -63,6 +63,7 @@ type Command struct {
 	helpTemplate  string                   // Can be defined by Application
 	helpFunc      func(*Command, []string) // Help can be defined by application
 	helpCommand   *Command                 // The help command
+	helpFlagVal   bool
 }
 
 // os.Args[1:] by default, if desired, can be overridden
@@ -301,6 +302,12 @@ func (c *Command) execute(a []string) (err error) {
 	if err != nil {
 		return err
 	} else {
+		// If help is called, regardless of other flags, we print that
+		if c.helpFlagVal {
+			c.Help()
+			return nil
+		}
+
 		argWoFlags := c.Flags().Args()
 		c.Run(c, argWoFlags)
 		return nil
@@ -349,6 +356,13 @@ func (c *Command) Execute() (err error) {
 			c.Usage()
 			return e
 		} else {
+
+			// If help is called, regardless of other flags, we print that
+			if c.helpFlagVal {
+				c.Help()
+				return nil
+			}
+
 			argWoFlags := c.Flags().Args()
 			if len(argWoFlags) > 0 {
 				c.Usage()
@@ -555,6 +569,7 @@ func (c *Command) Flags() *flag.FlagSet {
 			c.flagErrorBuf = new(bytes.Buffer)
 		}
 		c.flags.SetOutput(c.flagErrorBuf)
+		c.flags.BoolVar(&c.helpFlagVal, "help", false, "help for "+c.Name())
 	}
 	return c.flags
 }
@@ -617,7 +632,6 @@ func (c *Command) persistentFlag(name string) (flag *flag.Flag) {
 // Parses persistent flag tree & local flags
 func (c *Command) ParseFlags(args []string) (err error) {
 	c.mergePersistentFlags()
-
 	err = c.Flags().Parse(args)
 
 	// The upstream library adds spaces to the error