Help

--help pages are generated from your definitions:

$ app sync --help
Sync files

Usage:
  app sync [flags] <files>
  app sync <command>

Commands:
  repeat  Sync files repeatedly

Arguments:
  <files>  Path to the files (required)

Flags:
  -h, --help       Show help
  --mode <string>  Sync mode (choices: fast, safe; default: safe)
  -r, --repeat     Repeat the operation
  -v, --verbose    Increase verbosity (env: VERBOSE)
  --version        Show version

Pages are rendered by a HelpTemplate. To customise them, pass an instance as help to jinju(), either with options or by extending the class.

Options

jinju({ commands, help: new HelpTemplate({ sortFlags: false, showHidden: true }) });

Option	Default	Description
sortFlags	true	Sort flags by long name. With false, they keep definition order.
showHidden	false	Include hidden commands and flags.

Extending the template

Override any method to change part of the page, and call super to build on the default:

class MyHelp extends HelpTemplate {
	override formatFlag(flag: HelpFlag) {
		const [label, description] = super.formatFlag(flag);
		return [label, flag.source === 'builtin' ? `${description} (built-in)` : description] as const;
	}

	override sections(data: HelpData) {
		return [`${data.program.name} v${data.program.version}`, ...super.sections(data)];
	}
}

jinju({ version: '1.0.0', help: new MyHelp({ sortFlags: false }), commands });

Method	Default
render(data)	Joins sections(data) with blank lines and adds a trailing newline. Override it to replace the layout entirely
sections(data)	[description, usage, commands, args, flags], with empty sections left out
formatUsage, formatCommands, formatArgs, formatFlags	Each renders one section from data
commands(data), flags(data)	Choose what to list: hidden entries are left out unless showHidden, and flags are sorted unless sortFlags: false
formatCommand, formatArg, formatFlag	One [left, right] table row each
formatTags, formatValue, formatPath	(required; default: 3), default values, <project> deploy
formatTable(rows), formatSection(title, lines)	Layout primitives

The text render returns is printed as-is, so it should end with a newline.

Help data

HelpData holds the building blocks of a page, and the template decides what to use and how. It makes no layout decisions: nothing is filtered or sorted.

Field	Contents
program	name, version, description
path	The command path as { name, dynamic } parts. formatPath(path) gives <project> deploy
description, aliases, runnable	This level's description, its command's aliases, and whether it has a command to run
usage	Usage lines, e.g. app <project> deploy [flags] [<env>]
commands	Each subcommand: name, label, description, aliases, hidden, dynamic, full path, runnable, group (has subcommands)
args	Each arg in order: name, label (<env>), usage ([<env>]), source (command or scope), segment
flags	Each flag in definition order, hidden ones included: key, name, alias, kind (flag or switch), env, source (command, scope or builtin), hidden, label (-n, --dry-run <string>)

Args and flags also carry description, type, required, multiple, hasDefault, the raw default, choices, and options. options is everything passed to the creator, including min, max, integer, exists and the options of custom parsers.

See the Help API for every type.