Don't generate fish completion for hidden commands

Added the missing test case as well.

Signed-off-by: Sascha Grunert <sgrunert@suse.com>

docs_test.go

@@ -53,6 +53,9 @@ func testApp() *App {
 		Usage:   "retrieve generic information",
 	}, {
 		Name: "some-command",
+	}, {
+		Name:   "hidden-command",
+		Hidden: true,
 	}}
 	app.UsageText = "app [first_arg] [second_arg]"
 	app.Usage = "Some app"

fish.go

@@ -69,6 +69,10 @@ func (a *App) prepareFishCommands(commands []Command, allCommands *[]string, pre
 	for i := range commands {
 		command := &commands[i]
 
+		if command.Hidden {
+			continue
+		}
+
 		var completion strings.Builder
 		completion.WriteString(fmt.Sprintf(
 			"complete -r -c %s -n '%s' -a '%s'",