Method addArgument

lib/command.js:376–394

* Define argument syntax for command, adding a prepared argument. * * @param {Argument} argument * @return {Command} `this` command for chaining

(argument)

   * @return {Command} `this` command for chaining
   */
  addArgument(argument) {
    const previousArgument = this.registeredArguments.slice(-1)[0];
    if (previousArgument?.variadic) {
      throw new Error(
        `only the last argument can be variadic '${previousArgument.name()}'`,
      );
    }
    if (
      argument.required &&
      argument.defaultValue !== undefined &&
      argument.parseArg === undefined
    ) {
      throw new Error(
        `a default value for a required argument is never used: '${argument.name()}'`,
      );
    }
    this.registeredArguments.push(argument);
    return this;
  }

  /**
   * Customise or override default help command. By default a help command is automatically added if your command has subcommands.