Improve "command not found" error message

Author: parttimenerd

cf_cli_java_plugin.go

@@ -22,8 +22,10 @@ import (
 
 	"utils"
 
+	"github.com/lithammer/fuzzysearch/fuzzy"
 	guuid "github.com/satori/go.uuid"
 	"github.com/simonleung8/flags"
+	"sort"
 )
 
 // The JavaPlugin is a cf cli plugin that supports taking heap and thread dumps on demand
@@ -412,7 +414,18 @@ func (c *JavaPlugin) execute(commandExecutor cmd.CommandExecutor, uuidGenerator
 		for _, command := range commands {
 			avCommands = append(avCommands, command.Name)
 		}
-		return "", &InvalidUsageError{message: fmt.Sprintf("Unrecognized command %q: supported commands are %s' (see cf help)", commandName, strings.Join(avCommands, ", "))}
+		matches := fuzzy.RankFind(commandName, avCommands)
+		sort.Sort(matches)
+		matchedCommands := make([]string, 0, 3)
+		// first three matches
+		for i := 0; i < 3 && i < len(matches); i++ {
+			matchedCommands = append(matchedCommands, matches[i].Target)
+		}
+		// concat with or at the end
+		if len(matchedCommands) > 1 {
+			matchedCommands[len(matchedCommands)-1] = "or " + matchedCommands[len(matchedCommands)-1]
+		}
+		return "", &InvalidUsageError{message: fmt.Sprintf("Unrecognized command %q, did you mean: %s?", commandName, strings.Join(matchedCommands, ", "))}
 	}
 
 	command := commands[index]