ember-cli/ember-cli

'use strict';

const chalk = require('chalk');
const EOL = require('os').EOL;

module.exports = function (initialMargin, shouldDescriptionBeGrey) {
  initialMargin = initialMargin || '';

  let output = '';

  let options = this.anonymousOptions;

  // <anonymous-option-1> ...
  if (options.length) {
    output += ` ${chalk.yellow(
      options
        .map((option) => {
          // blueprints we insert brackets, commands already have them
          if (option.indexOf('<') === 0) {
            return option;
          } else {
            return `<${option}>`;
          }
        })
        .join(' ')
    )}`;
  }

  options = this.availableOptions;

  // <options...>
  if (options.length) {
    output += ` ${chalk.cyan('<options...>')}`;
  }

  // Description
  let description = this.description;
  if (description) {
    if (shouldDescriptionBeGrey) {
      description = chalk.grey(description);
    }
    output += `${EOL + initialMargin}  ${description}`;
  }

  // aliases: a b c
  if (this.aliases && this.aliases.length) {
    output += `${EOL + initialMargin}  ${chalk.grey(`aliases: ${this.aliases.filter((a) => a).join(', ')}`)}`;
  }

  // --available-option (Required) (Default: value)
  // ...
  options.forEach((option) => {
    output += `${EOL + initialMargin}  ${chalk.cyan(`--${option.name}`)}`;

    if (option.values) {
      output += chalk.cyan(`=${option.values.join('|')}`);
    }

    if (option.type) {
      let types = Array.isArray(option.type) ? option.type.map(formatType).join(', ') : formatType(option.type);

      output += ` ${chalk.cyan(`(${types})`)}`;
    }

    if (option.required) {
      output += ` ${chalk.cyan('(Required)')}`;
    }

    if (option.default !== undefined) {
      output += ` ${chalk.cyan(`(Default: ${formatValue(option.default)})`)}`;
    }

    if (option.description) {
      output += ` ${option.description}`;
    }

    if (option.aliases && option.aliases.length) {
      output += `${EOL + initialMargin}    ${chalk.grey(
        `aliases: ${option.aliases
          .map((a) => {
            if (typeof a === 'string') {
              return (a.length > 4 ? '--' : '-') + a + (option.type === Boolean ? '' : ' <value>');
            } else {
              let key = Object.keys(a)[0];
              return `${(key.length > 4 ? '--' : '-') + key} (--${option.name}=${formatValue(a[key])})`;
            }
          })
          .join(', ')}`
      )}`;
    }
  });

  return output;
};

function formatType(type) {
  return typeof type === 'string' ? formatValue(type) : type.name;
}

function formatValue(val) {
  return val === '' ? '""' : val;
}