structopt

Decorator-based CLI option parser

Features

• Strongly-Typed: Use class to declare arguments.
• Declarative: Instead of chaining methods, use class to declare what arguments are needed.
• Impressive: Automatically infers argument names from a property name.
• Friendly: Automatically generates help.

Install

npm install --save structopt

Or if you use Yarn:

yarn add structopt

Example

import { StructOpt, Option, fromArgs } from 'structopt'

@StructOpt({
  name: 'example',
  about: 'An example of StructOpt usage.',
})
class Opt {
  // short and long flags (-d, --debug) will be deduced from the field's name
  @Option({ short: true, long: true, description: 'Activate debug mode' })
  debug!: boolean

  // we don't want to name it "speed", need to look smart
  @Option({ short: '-v', long: '--velocity', defaultValue: '42', description: 'Set speed' })
  speed!: number

  @Option({ required: true, description: 'Input file' })
  input!: string

  @Option({ description: 'Output file, stdout if not present' })
  output?: string
}

const opt = fromArgs(Opt)
console.log(opt)

And run

$ ts-node examples/basic.ts --debug -v 80 /tmp/input_file

# Result:
# {
#   debug: true,
#   speed: 80,
#   input: '/tmp/input_file'
# }

It also auto generates help text:

$ ts-node -T examples/basic.ts -h

example 0.1.5
An example of StructOpt usage.

USAGE:
  basic.ts [FLAGS] [OPTIONS] <input> [ARGS]

FLAGS:
    -d, --debug    Activate debug mode

OPTIONS:
    -v, --velocity <speed>    Set speed [default: 42]
    -f,  <format>

ARGS:
    <input>     search pattern
    <output>    Output file, stdout if not present

Roadmap

• Class-validator integration
• Show other meta info
  • Author
  • Contact
  • Bug reports
• Sub-command style
• Multiple parameters
  • For named options (allow multiple times if an option is specified)
  • For arguments (like tar command)
• Environment variable fallback
• Custom parser, e.g. ) String to Date conversion