src/lib/cli/Command.js

/**
 * A command that can be run through the CLI.
 * @abstract
 */
export default class Command {
  /**
   * Creates a new Command with the given name and options.
   * @param {string} name The command's name.
   * @param {string} description The command's description.
   * @param {Object} options The options to apply.
   * @param {Map<string, Option>} options.options The options available for this command.
   * @param {string} [options.arguments] The command's argument string. See yargs' documentation
   * for details.
   * @param {number} [options.minArguments] The minimum number or (non-option) arguments the command
   * requires.
   * @param {number} [options.maxArguments] The maximum number or (non-option) arguments the command
   * requires.
   * @param {boolean} [options.strict=true] Throw error for unknown arguments.
   * @throws {Error} Throws an error if options.maxArguments is less than options.minArguments.
   * @see {@link yargs}
   */
  constructor(name, description, options = {}) {
    /**
     * The command's name.
     * @type {String}
     */
    this.name = name;

    /**
     * The command descriptions.
     * @type {String}
     */
    this.description = description;

    if (
      options.minArguments &&
      options.maxArguments !== undefined &&
      options.maxArguments < options.minArguments
    ) {
      throw new Error('options.maxArguments must not be less than options.minArguments');
    }

    /**
     * The command's raw options.
     * @type {Object}
     * @private
     */
    this._options = options;
  }

  /**
   * Runs the command with the current Cli instance. **Asynchronous commands should return a Promise
   * here.**.
   * @param {AtSCMCli} cli The current cli instance.
   */
  // eslint-disable-next-line no-unused-vars
  run(cli) {
    throw new Error('Must be implemented by all subclasses');
  }

  /**
   * Returns `true` if the command requires a {@link Liftoff.Environment} before it can be run.
   * @param {AtSCMCli} cli The current cli instance.
   * @return {boolean} `true` if the command requires a {@link Liftoff.Environment}.
   */
  // eslint-disable-next-line no-unused-vars
  requiresEnvironment(cli) {
    return true;
  }

  /**
   * Returns the usage string for the command. Something like "{name} {arguments}".
   * @type {string}
   */
  get usage() {
    if (this._options.arguments) {
      return `${this.name} ${this._options.arguments}`;
    }

    return this.name;
  }

  /**
   * The options available for the command.
   * @type {Map<string, Option>}
   */
  get options() {
    return this._options.options || {};
  }

  /**
   * The minimum and maximum number of (non-option) arguments the command handles.
   * @type {number[]}
   */
  get demandCommand() {
    const ret = [this._options.minArguments || 0];

    if (this._options.maxArguments !== undefined) {
      ret.push(this._options.maxArguments);
    }

    return ret;
  }

  /**
   * If an error should be thrown for unknown arguments.
   * @type {boolean}
   */
  get strict() {
    return this._options.strict !== undefined ? this._options.strict : true;
  }
}