From 3afa4db2c62a1ff4befba4660b6a3b057ebcdb8a Mon Sep 17 00:00:00 2001
From: Fabiano Franz <ffranz@redhat.com>
Date: Fri, 25 Sep 2015 11:41:47 -0300
Subject: [PATCH] Improve suggestions - prefix will match

---
 cobra_test.go | 36 +++++++++++++++++++++++-------------
 command.go    | 34 +++++++++++++++++++---------------
 2 files changed, 42 insertions(+), 28 deletions(-)

diff --git a/cobra_test.go b/cobra_test.go
index c9eef5d7..6e0e5e3b 100644
--- a/cobra_test.go
+++ b/cobra_test.go
@@ -816,22 +816,32 @@ func TestRootSuggestions(t *testing.T) {
 	cmd.AddCommand(cmdTimes)
 
 	tests := map[string]string{
-		"time":  "times",
-		"tiems": "times",
-		"timeS": "times",
-		"rimes": "times",
+		"time":     "times",
+		"tiems":    "times",
+		"tims":     "times",
+		"timeS":    "times",
+		"rimes":    "times",
+		"ti":       "times",
+		"t":        "times",
+		"timely":   "times",
+		"ri":       "",
+		"timezone": "",
+		"foo":      "",
 	}
 
 	for typo, suggestion := range tests {
-		cmd.DisableSuggestions = false
-		result := simpleTester(cmd, typo)
-		if expected := fmt.Sprintf(outputWithSuggestions, typo, suggestion); result.Output != expected {
-			t.Errorf("Unexpected response.\nExpecting to be:\n %q\nGot:\n %q\n", expected, result.Output)
-		}
-		cmd.DisableSuggestions = true
-		result = simpleTester(cmd, typo)
-		if expected := fmt.Sprintf(outputWithoutSuggestions, typo); result.Output != expected {
-			t.Errorf("Unexpected response.\nExpecting to be:\n %q\nGot:\n %q\n", expected, result.Output)
+		for _, suggestionsDisabled := range []bool{false, true} {
+			cmd.DisableSuggestions = suggestionsDisabled
+			result := simpleTester(cmd, typo)
+			expected := ""
+			if len(suggestion) == 0 || suggestionsDisabled {
+				expected = fmt.Sprintf(outputWithoutSuggestions, typo)
+			} else {
+				expected = fmt.Sprintf(outputWithSuggestions, typo, suggestion)
+			}
+			if result.Output != expected {
+				t.Errorf("Unexpected response.\nExpecting to be:\n %q\nGot:\n %q\n", expected, result.Output)
+			}
 		}
 	}
 }
diff --git a/command.go b/command.go
index 0cc0b72a..44e962ed 100644
--- a/command.go
+++ b/command.go
@@ -429,33 +429,37 @@ func (c *Command) Find(args []string) (*Command, []string, error) {
 
 	// root command with subcommands, do subcommand checking
 	if commandFound == c && len(argsWOflags) > 0 {
-		suggestions := ""
+		suggestionsString := ""
 		if !c.DisableSuggestions {
 			if c.SuggestionsMinimumDistance <= 0 {
 				c.SuggestionsMinimumDistance = 2
 			}
-			similar := []string{}
-			for _, cmd := range c.commands {
-				if cmd.IsAvailableCommand() {
-					levenshtein := ld(argsWOflags[0], cmd.Name(), true)
-					if levenshtein <= c.SuggestionsMinimumDistance {
-						similar = append(similar, cmd.Name())
-					}
-				}
-			}
-			if len(similar) > 0 {
-				suggestions += "\n\nDid you mean this?\n"
-				for _, s := range similar {
-					suggestions += fmt.Sprintf("\t%v\n", s)
+			if suggestions := c.SuggestionsFor(argsWOflags[0]); len(suggestions) > 0 {
+				suggestionsString += "\n\nDid you mean this?\n"
+				for _, s := range suggestions {
+					suggestionsString += fmt.Sprintf("\t%v\n", s)
 				}
 			}
 		}
-		return commandFound, a, fmt.Errorf("unknown command %q for %q%s", argsWOflags[0], commandFound.CommandPath(), suggestions)
+		return commandFound, a, fmt.Errorf("unknown command %q for %q%s", argsWOflags[0], commandFound.CommandPath(), suggestionsString)
 	}
 
 	return commandFound, a, nil
 }
 
+func (c *Command) SuggestionsFor(cmdName string) []string {
+	suggestions := []string{}
+	for _, cmd := range c.commands {
+		if cmd.IsAvailableCommand() {
+			levenshtein := ld(cmdName, cmd.Name(), true)
+			if levenshtein <= c.SuggestionsMinimumDistance || strings.HasPrefix(strings.ToLower(cmd.Name()), strings.ToLower(cmdName)) {
+				suggestions = append(suggestions, cmd.Name())
+			}
+		}
+	}
+	return suggestions
+}
+
 func (c *Command) Root() *Command {
 	var findRoot func(*Command) *Command