Method addHelpText

lib/command.js:2670–2691

* Add additional text to be displayed with the built-in help. * * Position is 'before' or 'after' to affect just this command, * and 'beforeAll' or 'afterAll' to affect this command and all its subcommands. * * @param {string} position - before or after built-in help * @param {(str

(position, text)

   */

  addHelpText(position, text) {
    const allowedValues = ['beforeAll', 'before', 'after', 'afterAll'];
    if (!allowedValues.includes(position)) {
      throw new Error(`Unexpected value for position to addHelpText.
Expecting one of '${allowedValues.join("', '")}'`);
    }

    const helpEvent = `${position}Help`;
    this.on(helpEvent, (/** @type {HelpTextEventContext} */ context) => {
      let helpStr;
      if (typeof text === 'function') {
        helpStr = text({ error: context.error, command: context.command });
      } else {
        helpStr = text;
      }
      // Ignore falsy value when nothing to output.
      if (helpStr) {
        context.write(`${helpStr}\n`);
      }
    });
    return this;
  }

  /**
   * Output help information if help flags specified