Command now uses the new usage mechanism

Author: FollowTheProcess

command.go

@@ -583,14 +583,12 @@ func writeArgumentsSection(cmd *Command, s *strings.Builder) error {
 	tw := style.Tabwriter(s)
 
 	for _, arg := range cmd.args {
-		switch arg.Default() {
-		case "":
-			// It's required
-			fmt.Fprintf(tw, "  %s\t%s\t%s\t[required]\n", style.Bold.Text(arg.Name()), arg.Type(), arg.Usage())
-		default:
-			// It has a default
-			fmt.Fprintf(tw, "  %s\t%s\t%s\t[default %s]\n", style.Bold.Text(arg.Name()), arg.Type(), arg.Usage(), arg.Default())
+		line := fmt.Sprintf("  %s\t%s\t%s\t[required]", style.Bold.Text(arg.Name()), arg.Type(), arg.Usage())
+		if arg.Default() != "" {
+			line = fmt.Sprintf("  %s\t%s\t%s\t[default %s]", style.Bold.Text(arg.Name()), arg.Type(), arg.Usage(), arg.Default())
 		}
+
+		fmt.Fprintln(tw, line)
 	}
 
 	if err := tw.Flush(); err != nil {
@@ -669,14 +667,25 @@ func writeFlags(cmd *Command, s *strings.Builder) error {
 			shorthand = "N/A"
 		}
 
-		fmt.Fprintf(
-			tw,
-			"  %s\t--%s\t%s\t%s\n",
-			style.Bold.Text(shorthand),
+		line := fmt.Sprintf(
+			"  %s\t--%s\t%s\t%s\t", style.Bold.Text(shorthand),
 			style.Bold.Text(name),
 			fl.Type(),
 			fl.Usage(),
 		)
+
+		if fl.Default() != "" {
+			line = fmt.Sprintf(
+				"  %s\t--%s\t%s\t%s\t[default: %s]",
+				style.Bold.Text(shorthand),
+				style.Bold.Text(name),
+				fl.Type(),
+				fl.Usage(),
+				fl.Default(),
+			)
+		}
+
+		fmt.Fprintln(tw, line)
 	}
 
 	if err := tw.Flush(); err != nil {

internal/flag/flag.go

@@ -55,19 +55,6 @@ func New[T flag.Flaggable](p *T, name string, short rune, usage string, config C
 		short: short,
 	}
 
-	// TODO(@FollowTheProcess): This needs to live in command.go and we should iterate over the flagset
-	// adding the values to the tabwriter as we go rather than relying on the flagset.Usage() method
-	// to provide *all* the usage
-
-	// If the default value is not the zero value for the type, it is treated as
-	// significant and shown to the user
-	flag.usage += "\t"
-	if !isZeroIsh(*p) {
-		// \t so that defaults get aligned by tabwriter when the command
-		// dumps the flags
-		flag.usage += fmt.Sprintf("[default: %s]", flag.String())
-	}
-
 	return flag, nil
 }
 
@@ -87,6 +74,21 @@ func (f Flag[T]) Usage() string {
 	return f.usage
 }
 
+// Default returns the default value for the flag, as a string.
+//
+// If the flag's default is unset (i.e. the zero value for its type),
+// an empty string is returned.
+func (f Flag[T]) Default() string {
+	// Special case a --help flag, because if we didn't, when you call --help
+	// it would show up with a default of true because you've passed it
+	// so it's value is true here
+	if isZeroIsh(*f.value) || f.name == "help" {
+		return ""
+	}
+
+	return f.String()
+}
+
 // NoArgValue returns a string representation of value the flag should hold
 // when it is given no arguments on the command line. For example a boolean flag
 // --delete, when passed without arguments implies --delete true.

internal/flag/value.go

@@ -14,6 +14,12 @@ type Value interface {
 	// String returns the stored value of a flag as a string.
 	String() string
 
+	// Default return the default value of a flag as a string.
+	//
+	// If the flag's default is the zero value for it's type,
+	// an empty string is returned.
+	Default() string
+
 	// NoArgValue returns astring representation of the value of the flag when no
 	// args are passed (e.g --bool implies --bool true).
 	NoArgValue() string