From 881657297e605dc96dc0369758a843f043d12d17 Mon Sep 17 00:00:00 2001
From: Sam Ghods <sam@box.com>
Date: Thu, 25 Sep 2014 16:03:34 -0700
Subject: [PATCH] Replace prefix matching with aliases

---
 cobra_test.go | 36 +++++++++---------------------------
 command.go    | 38 +++++++++++++++++++++++++-------------
 2 files changed, 34 insertions(+), 40 deletions(-)

diff --git a/cobra_test.go b/cobra_test.go
index 5f4af277..7b5ed623 100644
--- a/cobra_test.go
+++ b/cobra_test.go
@@ -26,9 +26,10 @@ var cmdPrint = &Command{
 }
 
 var cmdEcho = &Command{
-	Use:   "echo [string to echo]",
-	Short: "Echo anything to the screen",
-	Long:  `an utterly useless command for testing.`,
+	Use:     "echo [string to echo]",
+	Aliases: []string{"say"},
+	Short:   "Echo anything to the screen",
+	Long:    `an utterly useless command for testing.`,
 	Run: func(cmd *Command, args []string) {
 		te = args
 	},
@@ -38,7 +39,9 @@ var cmdTimes = &Command{
 	Use:   "times [# times] [string to echo]",
 	Short: "Echo anything to the screen more times",
 	Long:  `an slightly useless command for testing.`,
-	Run:   timesRunner,
+	Run: func(cmd *Command, args []string) {
+		tt = args
+	},
 }
 
 var cmdRootNoRun = &Command{
@@ -62,10 +65,6 @@ var cmdRootWithRun = &Command{
 	},
 }
 
-func timesRunner(cmd *Command, args []string) {
-	tt = args
-}
-
 func flagInit() {
 	cmdEcho.ResetFlags()
 	cmdPrint.ResetFlags()
@@ -195,8 +194,8 @@ func TestChildCommand(t *testing.T) {
 	}
 }
 
-func TestChildCommandPrefix(t *testing.T) {
-	noRRSetupTest("ech tim one two")
+func TestCommandAlias(t *testing.T) {
+	noRRSetupTest("say times one two")
 
 	if te != nil || tp != nil {
 		t.Error("Wrong command called")
@@ -226,23 +225,6 @@ func TestChildSameName(t *testing.T) {
 	}
 }
 
-func TestChildSameNamePrefix(t *testing.T) {
-	c := initializeWithSameName()
-	c.AddCommand(cmdPrint, cmdEcho)
-	c.SetArgs(strings.Split("pr one two", " "))
-	c.Execute()
-
-	if te != nil || tt != nil {
-		t.Error("Wrong command called")
-	}
-	if tp == nil {
-		t.Error("Wrong command called")
-	}
-	if strings.Join(tp, " ") != "one two" {
-		t.Error("Command didn't parse correctly")
-	}
-}
-
 func TestFlagLong(t *testing.T) {
 	noRRSetupTest("echo --intone=13 something here")
 
diff --git a/command.go b/command.go
index 17a5eacb..d2914378 100644
--- a/command.go
+++ b/command.go
@@ -35,6 +35,8 @@ type Command struct {
 	name string
 	// The one-line usage message.
 	Use string
+	// An array of aliases that can be used instead of the first word in Use.
+	Aliases []string
 	// The short description shown in the 'help' output.
 	Short string
 	// The long message shown in the 'help <this-command>' output.
@@ -189,7 +191,10 @@ func (c *Command) UsageTemplate() string {
 		return `{{ $cmd := . }}
 Usage: {{if .Runnable}}
   {{.UseLine}}{{if .HasFlags}} [flags]{{end}}{{end}}{{if .HasSubCommands}}
-  {{ .CommandPath}} [command]{{end}}
+  {{ .CommandPath}} [command]{{end}}{{if gt .Aliases 0}}
+
+Aliases:
+  {{.NameAndAliases}}{{end}}
 {{ if .HasSubCommands}}
 Available Commands: {{range .Commands}}{{if .Runnable}}
   {{rpad .Use .UsagePadding }} {{.Short}}{{end}}{{end}}
@@ -281,19 +286,11 @@ func (c *Command) Find(arrs []string) (*Command, []string, error) {
 		if len(args) > 0 && c.HasSubCommands() {
 			argsWOflags := stripFlags(args)
 			if len(argsWOflags) > 0 {
-				matches := make([]*Command, 0)
 				for _, cmd := range c.commands {
-					if cmd.Name() == argsWOflags[0] { // exact name match
-						return innerfind(cmd, argsMinusX(args, cmd.Name()))
-					} else if strings.HasPrefix(cmd.Name(), argsWOflags[0]) { // prefix match
-						matches = append(matches, cmd)
+					if cmd.Name() == argsWOflags[0] || cmd.HasAlias(argsWOflags[0]) { // exact name or alias match
+						return innerfind(cmd, argsMinusX(args, argsWOflags[0]))
 					}
 				}
-
-				// only accept a single prefix match - multiple matches would be ambiguous
-				if len(matches) == 1 {
-					return innerfind(matches[0], argsMinusX(args, argsWOflags[0]))
-				}
 			}
 		}
 
@@ -302,8 +299,9 @@ func (c *Command) Find(arrs []string) (*Command, []string, error) {
 
 	commandFound, a := innerfind(c, arrs)
 
-	// if commander returned and not appropriately matched return nil & error
-	if commandFound.Name() == c.Name() && !strings.HasPrefix(commandFound.Name(), arrs[0]) {
+	// if commander returned and the first argument (if it exists) doesn't
+	// match the command name, return nil & error
+	if commandFound.Name() == c.Name() && len(arrs[0]) > 0 && commandFound.Name() != arrs[0] {
 		return nil, a, fmt.Errorf("unknown command %q\nRun 'help' for usage.\n", a[0])
 	}
 
@@ -614,6 +612,20 @@ func (c *Command) Name() string {
 	return name
 }
 
+// Determine if a given string is an alias of the command.
+func (c *Command) HasAlias(s string) bool {
+	for _, a := range c.Aliases {
+		if a == s {
+			return true
+		}
+	}
+	return false
+}
+
+func (c *Command) NameAndAliases() string {
+	return strings.Join(append([]string{c.Name()}, c.Aliases...), ", ")
+}
+
 // Determine if the command is itself runnable
 func (c *Command) Runnable() bool {
 	return c.Run != nil