From 647c6ea21baa28192e5c4339ed4cdf83e994036e Mon Sep 17 00:00:00 2001
From: Ophestra <cat@gensokyo.uk>
Date: Sun, 23 Feb 2025 01:36:48 +0900
Subject: [PATCH] command: hide internal commands

This marks commands as internal via a magic usage string.

Signed-off-by: Ophestra <cat@gensokyo.uk>
---
 command/command.go    | 3 +++
 command/help.go       | 6 ++++--
 command/parse_test.go | 1 +
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/command/command.go b/command/command.go
index 525dde3..eeec135 100644
--- a/command/command.go
+++ b/command/command.go
@@ -6,6 +6,9 @@ import (
 	"strings"
 )
 
+// UsageInternal causes the command to be hidden from help text when set as the usage string.
+const UsageInternal = "internal"
+
 type (
 	// HandlerFunc is called when matching a directly handled subcommand tree.
 	HandlerFunc = func(args []string) error
diff --git a/command/help.go b/command/help.go
index a373540..cb22ce5 100644
--- a/command/help.go
+++ b/command/help.go
@@ -44,8 +44,10 @@ func (n *node) writeCommands(w io.Writer) error {
 	if n == nil {
 		return nil
 	}
-	if _, err := fmt.Fprintf(w, "\t%s\t%s\n", n.name, n.usage); err != nil {
-		return err
+	if n.usage != UsageInternal {
+		if _, err := fmt.Fprintf(w, "\t%s\t%s\n", n.name, n.usage); err != nil {
+			return err
+		}
 	}
 	return n.next.writeCommands(w)
 }
diff --git a/command/parse_test.go b/command/parse_test.go
index 3174dcc..4bb924f 100644
--- a/command/parse_test.go
+++ b/command/parse_test.go
@@ -289,6 +289,7 @@ func buildTestCommand(wout, wlog io.Writer) (c command.Command) {
 		})
 
 	c.New("empty", "empty subcommand")
+	c.New("hidden", command.UsageInternal)
 
 	c.New("join", "wraps strings.Join").
 		Command("out", "write result to wout", func(args []string) error {