handle invalid commands (kubeshop#1053)

(cherry picked from commit 760e70d)

pkg/execute/executor.go

@@ -28,6 +28,8 @@ const (
 	anonymizedInvalidVerb = "{invalid verb}"
 
 	lineLimitToShowFilter = 16
+
+	invalidCmdWithUsage = "error: unknown option `%s`\nusage: %s"
 )
 
 var newLinePattern = regexp.MustCompile(`\r?\n`)
@@ -168,8 +170,9 @@ func (e *DefaultExecutor) Execute(ctx context.Context) interactive.CoreMessage {
 			reportedCmd = fmt.Sprintf("%s {invalid feature}", reportedCmd)
 		}
 		e.reportCommand(ctx, "", reportedCmd, false, cmdCtx)
-		msg := e.cmdsMapping.HelpMessageForVerb(cmdVerb)
-		return respond(msg, cmdCtx)
+		helpMsg := e.cmdsMapping.HelpMessageForVerb(cmdVerb)
+		responseMsg := fmt.Sprintf(invalidCmdWithUsage, cmdRes, helpMsg)
+		return respond(responseMsg, cmdCtx)
 	} else {
 		cmdToReport := string(cmdVerb)
 		if cmdRes != "" {

pkg/execute/mapping.go

@@ -14,7 +14,8 @@ import (
 )
 
 const (
-	helpMsgHeader = "%s %s [feature]\n\nAvailable features:\n"
+	helpMsgHeaderWithFeatures = "%s %s [feature]\n\nAvailable features:\n"
+	helpMsgHeader             = "%s %s"
 	// noFeature is used for commands that have no features defined
 	noFeature = ""
 	// incompleteCmdMsg incomplete command response message
@@ -127,8 +128,12 @@ func (m *CommandMapping) HelpMessageForVerb(verb command.Verb) string {
 	}
 	buf := new(bytes.Buffer)
 	w := tabwriter.NewWriter(buf, 3, 0, 1, ' ', 0)
+	if len(cmd) > 0 && cmd[0].Name != "" {
+		fmt.Fprintf(w, helpMsgHeaderWithFeatures, api.MessageBotNamePlaceholder, verb)
+	} else {
+		fmt.Fprintf(w, helpMsgHeader, api.MessageBotNamePlaceholder, verb)
+	}
 
-	fmt.Fprintf(w, helpMsgHeader, api.MessageBotNamePlaceholder, verb)
 	for _, feature := range cmd {
 		aliases := removeEmptyFeatures(feature.Aliases)
 		fmtStr := fmt.Sprintf("%s\t", feature.Name)