yeow is a CLI helper with attitude — part meow, part yargs, and built to spite the both of them.

things yeow does:

• parse arguments
• assert types
• fail if given incorrect arguments

things yeow doesn't do:

• negate arguments with --no-
• interpret arguments as an array
• restrict valid values to a predetermined list

$ npm i --save yeow

#!/usr/bin/env node
const args = require("yeow")({
  "exclamation": {
    type: "string",
    required: true
  },
  "int": {
    type: "number",
    aliases: "--integer",
    default: 16
  }
});

console.log(args);

$ ./logger.js "yeow!"
{ exclamation: 'yeow!', int: 16 }

$ ./logger.js "cool!" --integer 100
{ exclamation: 'cool!', int: 100 }

returns an object of parsed arguments from the passed obj.

type: object

each key is a human-readable argument name. the value is an object with any of:

type: string

type of the argument.

possible values:

• string
• number
• file

if this is omitted, the argument will become a simple true/false flag.

type: boolean
default: false

whether the argument is required. required arguments ignore aliases and default.

the n-th argument for which required is set to true must be passed as the n-th argument to the program.

type: string

error message to output if the argument is omitted.

if the argument is not required, this will be ignored.

type: string

valid aliases for the argument, space-slash-space separated.

example values:

• -a
• -a / --argument

if the argument is required, this will be ignored.

type: string

valid file extensions for the argument, space-slash-space separated.

example values:

• .txt
• .js / .jsx

if the argument's type is not file, this will be ignored.
if this is omitted, the argument will accept files of any extension.

type: string | number

a default value the argument will have if it is omitted. the value's type should match the argument's type.

if the argument is required, this will be ignored.

type: string

error message to output if the argument is passed with an invalid type.

const args = require("yeow")({
  "script": {
    type: "file",
    extensions: ".js",
    required: true,
    missing: "a file must be passed",
    invalid: "not a .js file"
  },
  "delay": {
    type: "number",
    aliases: "-d / --delay",
    default: 1
  },
  "input": {
    type: "string",
    aliases: "--input",
  },
  "verbose": {
    aliases: "-v / --verbose"
  }
});

you can support the development of this project and others via Patreon: