clap
v3.1.1
Published
Command line argument parser
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Clap.js
A library for node.js to build command-line interfaces (CLI). With its help, making a simple CLI application is a trivial task. It equally excels in complex tools with a lot of subcommands and specific features. This library supports argument coercion and completion suggestion — typing the commands is much easier.
Inspired by commander.js
Features:
- TBD
Usage
npm install clap
const cli = require('clap');
const myCommand = cli.command('my-command [optional-arg]')
.description('Optional description')
.version('1.2.3')
.option('-b, --bool', 'Bollean option')
.option('--foo <foo>', 'Option with required argument')
.option('--bar [bar]', 'Option with optional argument')
.option('--baz [value]', 'Option with optional argument and normalize function',
value => Number(value),
123 // 123 is default
)
.action(function({ options, args, literalArgs }) {
// options is an object with collected values
// args goes before options
// literal args goes after "--"
});
myCommand.run(); // the same as "myCommnad.run(process.argv.slice(2))"
myCommand.run(['--foo', '123', '-b'])
// sub-commands
myCommand
.command('nested')
.option('-q, --quz', 'Some parameter', 'Default value')
// ...
.end()
.command('another-command [arg1] [arg2]')
// ...
.command('level3-command')
//...
API
Command
.command()
// definition
.description(value)
.version(value, usage, description, action)
.help(usage, description, action)
.option(usage, description, ...options)
.command(usageOrCommand)
.extend(fn, ...options)
.end()
// argv processing pipeline handler setters
.init(command, context)
.applyConfig(context)
.prerareContenxt(context)
.action(context)
// main methods
.parse(argv, suggest)
.run(argv)
// misc
.clone(deep)
.createOptionValues()
.getCommand(name)
.getCommands()
.getOption(name)
.getOptions()
.outputHelp()
.option(usage, description, ...options)
There are two usage:
.option(usage, description, normalize, value)
.option(usage, description, options)
Where options
:
{
default: any, // default value
normalize: (value, oldValue) => { ... }, // any value for option is passing through this function and its result stores as option value
shortcut: (value, oldValue) => { ... }, // for shortcut options, the handler is executed after the value is set, and its result (an object) is used as a source of values for other options
action: () => { ... }, // for an action option, which breaks regular args processing and preform and action (e.g. show help or version)
config: boolean // mark option is about config and should be applied before `applyConfig()`
}
Argv processing
init(command, context)
// before arguments parsing- invoke action option and exit if any
- apply config options
applyConfig(context)
- apply all the rest options
prepareContext(context)
// after arguments parsing- switch to next command -> command is prescending
init(command, context)
- invoke action option and exit if any
- apply config options
applyConfig(context)
- apply all the rest options
prepareContext(context)
// after arguments parsing- switch to next command
- ...
action(context)
-> command is target
- switch to next command
action(context)
-> command is target
- switch to next command -> command is prescending
License
MIT