@jil/args/src/format.ts

A convention based argument parsing and formatting library, with strict validation checks

import {ArgList, Arguments, Argv, OptionMap, ValueType} from './types';

function mapToStringList(value: ValueType): ArgList {
  if (!Array.isArray(value)) {
    return [String(value)];
  }

  return (value as string[]).map(String);
}

/**
 * Format a parsed arguments object back into a command line list of arguments.
 */
export function format(argument: Partial<Arguments<OptionMap, ArgList>>): Argv {
  const {command = [], options = {}, params = [], rest = []} = argument;
  const args: Argv = [];

  // Commands
  if (command.length > 0) {
    args.push(command.join(':'));
  }

  // Options
  Object.entries(options).forEach(([name, value]) => {
    if (typeof value === 'boolean') {
      args.push(`--${!value ? 'no-' : ''}${name}`);
    } else {
      args.push(`--${name}`, ...mapToStringList(value));
    }
  });

  // Params
  if (params.length > 0) {
    args.push(...mapToStringList(params));
  }

  // Rest
  if (rest.length > 0) {
    args.push('--', ...mapToStringList(rest));
  }

  return args;
}