QuickRef.txt

fncli Quick Reference

import fncli from "fncli" // or require
fncli(async function main(arg, optarg="default"){
  // This signature becomes usage: ...
}) 

It turns your `main()` into a CLI and `argv` into a function call.
Use destructuring for options:

async function main({v: verbose=false, port=8080}, ...rest){
  // This signature becomes usage: ... 
}

Multiple commands supported with an object:

fncli({
  async login({prod=true}) {},
  async logout() {}
})

POSITIONAL ARGUMENTS
  name                      required positional arg
  name = "x"                optional positional with default
  ...names                  rest positional (zero or more)

OPTIONS
  {flag = false}            --flag boolean flag
  {opt = "x"}               --opt=<value> with default
  {f: flag = false}         -f / --flag (short alias)

COMMANDS
  object of functions       sub-commands (function names)
  nested objects            nested sub-commands

COMMENTS & HELP
  // comment before params  command synopsis
  // comment after param    per-arg/option description

ERROR HANDLING
  return "error: ..."       prints usage + error, exit code 1
  throw "error: ..."        prints usage + error, exit code 1

SPECIAL
  async function            awaited before exit
  -- in argv                stops option parsing
  -h / --help               added by default (help: true)

EXIT CODES
  0                         success
  1                         handler validation/exception
  2                         usage error (missing args, invalid options)

EXAMPLE WITH USAGE DESCRIPTIONS

function clone(
  url,                      // Repository URL
  {depth = undefined}       // Shallow clone depth
) { /* ... */ }

fncli({ clone })

$ script clone https://github.com/user/repo --depth=1