Index: node_modules/commander/index.js
===================================================================
--- node_modules/commander/index.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/commander/index.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,2217 @@
+/**
+ * Module dependencies.
+ */
+
+const EventEmitter = require('events').EventEmitter;
+const childProcess = require('child_process');
+const path = require('path');
+const fs = require('fs');
+
+// @ts-check
+
+// Although this is a class, methods are static in style to allow override using subclass or just functions.
+class Help {
+  constructor() {
+    this.helpWidth = undefined;
+    this.sortSubcommands = false;
+    this.sortOptions = false;
+  }
+
+  /**
+   * Get an array of the visible subcommands. Includes a placeholder for the implicit help command, if there is one.
+   *
+   * @param {Command} cmd
+   * @returns {Command[]}
+   */
+
+  visibleCommands(cmd) {
+    const visibleCommands = cmd.commands.filter(cmd => !cmd._hidden);
+    if (cmd._hasImplicitHelpCommand()) {
+      // Create a command matching the implicit help command.
+      const args = cmd._helpCommandnameAndArgs.split(/ +/);
+      const helpCommand = cmd.createCommand(args.shift())
+        .helpOption(false);
+      helpCommand.description(cmd._helpCommandDescription);
+      helpCommand._parseExpectedArgs(args);
+      visibleCommands.push(helpCommand);
+    }
+    if (this.sortSubcommands) {
+      visibleCommands.sort((a, b) => {
+        return a.name().localeCompare(b.name());
+      });
+    }
+    return visibleCommands;
+  }
+
+  /**
+   * Get an array of the visible options. Includes a placeholder for the implicit help option, if there is one.
+   *
+   * @param {Command} cmd
+   * @returns {Option[]}
+   */
+
+  visibleOptions(cmd) {
+    const visibleOptions = cmd.options.filter((option) => !option.hidden);
+    // Implicit help
+    const showShortHelpFlag = cmd._hasHelpOption && cmd._helpShortFlag && !cmd._findOption(cmd._helpShortFlag);
+    const showLongHelpFlag = cmd._hasHelpOption && !cmd._findOption(cmd._helpLongFlag);
+    if (showShortHelpFlag || showLongHelpFlag) {
+      let helpOption;
+      if (!showShortHelpFlag) {
+        helpOption = cmd.createOption(cmd._helpLongFlag, cmd._helpDescription);
+      } else if (!showLongHelpFlag) {
+        helpOption = cmd.createOption(cmd._helpShortFlag, cmd._helpDescription);
+      } else {
+        helpOption = cmd.createOption(cmd._helpFlags, cmd._helpDescription);
+      }
+      visibleOptions.push(helpOption);
+    }
+    if (this.sortOptions) {
+      const getSortKey = (option) => {
+        // WYSIWYG for order displayed in help with short before long, no special handling for negated.
+        return option.short ? option.short.replace(/^-/, '') : option.long.replace(/^--/, '');
+      };
+      visibleOptions.sort((a, b) => {
+        return getSortKey(a).localeCompare(getSortKey(b));
+      });
+    }
+    return visibleOptions;
+  }
+
+  /**
+   * Get an array of the arguments which have descriptions.
+   *
+   * @param {Command} cmd
+   * @returns {{ term: string, description:string }[]}
+   */
+
+  visibleArguments(cmd) {
+    if (cmd._argsDescription && cmd._args.length) {
+      return cmd._args.map((argument) => {
+        return { term: argument.name, description: cmd._argsDescription[argument.name] || '' };
+      }, 0);
+    }
+    return [];
+  }
+
+  /**
+   * Get the command term to show in the list of subcommands.
+   *
+   * @param {Command} cmd
+   * @returns {string}
+   */
+
+  subcommandTerm(cmd) {
+    // Legacy. Ignores custom usage string, and nested commands.
+    const args = cmd._args.map(arg => humanReadableArgName(arg)).join(' ');
+    return cmd._name +
+      (cmd._aliases[0] ? '|' + cmd._aliases[0] : '') +
+      (cmd.options.length ? ' [options]' : '') + // simplistic check for non-help option
+      (args ? ' ' + args : '');
+  }
+
+  /**
+   * Get the option term to show in the list of options.
+   *
+   * @param {Option} option
+   * @returns {string}
+   */
+
+  optionTerm(option) {
+    return option.flags;
+  }
+
+  /**
+   * Get the longest command term length.
+   *
+   * @param {Command} cmd
+   * @param {Help} helper
+   * @returns {number}
+   */
+
+  longestSubcommandTermLength(cmd, helper) {
+    return helper.visibleCommands(cmd).reduce((max, command) => {
+      return Math.max(max, helper.subcommandTerm(command).length);
+    }, 0);
+  };
+
+  /**
+   * Get the longest option term length.
+   *
+   * @param {Command} cmd
+   * @param {Help} helper
+   * @returns {number}
+   */
+
+  longestOptionTermLength(cmd, helper) {
+    return helper.visibleOptions(cmd).reduce((max, option) => {
+      return Math.max(max, helper.optionTerm(option).length);
+    }, 0);
+  };
+
+  /**
+   * Get the longest argument term length.
+   *
+   * @param {Command} cmd
+   * @param {Help} helper
+   * @returns {number}
+   */
+
+  longestArgumentTermLength(cmd, helper) {
+    return helper.visibleArguments(cmd).reduce((max, argument) => {
+      return Math.max(max, argument.term.length);
+    }, 0);
+  };
+
+  /**
+   * Get the command usage to be displayed at the top of the built-in help.
+   *
+   * @param {Command} cmd
+   * @returns {string}
+   */
+
+  commandUsage(cmd) {
+    // Usage
+    let cmdName = cmd._name;
+    if (cmd._aliases[0]) {
+      cmdName = cmdName + '|' + cmd._aliases[0];
+    }
+    let parentCmdNames = '';
+    for (let parentCmd = cmd.parent; parentCmd; parentCmd = parentCmd.parent) {
+      parentCmdNames = parentCmd.name() + ' ' + parentCmdNames;
+    }
+    return parentCmdNames + cmdName + ' ' + cmd.usage();
+  }
+
+  /**
+   * Get the description for the command.
+   *
+   * @param {Command} cmd
+   * @returns {string}
+   */
+
+  commandDescription(cmd) {
+    // @ts-ignore: overloaded return type
+    return cmd.description();
+  }
+
+  /**
+   * Get the command description to show in the list of subcommands.
+   *
+   * @param {Command} cmd
+   * @returns {string}
+   */
+
+  subcommandDescription(cmd) {
+    // @ts-ignore: overloaded return type
+    return cmd.description();
+  }
+
+  /**
+   * Get the option description to show in the list of options.
+   *
+   * @param {Option} option
+   * @return {string}
+   */
+
+  optionDescription(option) {
+    if (option.negate) {
+      return option.description;
+    }
+    const extraInfo = [];
+    if (option.argChoices) {
+      extraInfo.push(
+        // use stringify to match the display of the default value
+        `choices: ${option.argChoices.map((choice) => JSON.stringify(choice)).join(', ')}`);
+    }
+    if (option.defaultValue !== undefined) {
+      extraInfo.push(`default: ${option.defaultValueDescription || JSON.stringify(option.defaultValue)}`);
+    }
+    if (extraInfo.length > 0) {
+      return `${option.description} (${extraInfo.join(', ')})`;
+    }
+    return option.description;
+  };
+
+  /**
+   * Generate the built-in help text.
+   *
+   * @param {Command} cmd
+   * @param {Help} helper
+   * @returns {string}
+   */
+
+  formatHelp(cmd, helper) {
+    const termWidth = helper.padWidth(cmd, helper);
+    const helpWidth = helper.helpWidth || 80;
+    const itemIndentWidth = 2;
+    const itemSeparatorWidth = 2; // between term and description
+    function formatItem(term, description) {
+      if (description) {
+        const fullText = `${term.padEnd(termWidth + itemSeparatorWidth)}${description}`;
+        return helper.wrap(fullText, helpWidth - itemIndentWidth, termWidth + itemSeparatorWidth);
+      }
+      return term;
+    };
+    function formatList(textArray) {
+      return textArray.join('\n').replace(/^/gm, ' '.repeat(itemIndentWidth));
+    }
+
+    // Usage
+    let output = [`Usage: ${helper.commandUsage(cmd)}`, ''];
+
+    // Description
+    const commandDescription = helper.commandDescription(cmd);
+    if (commandDescription.length > 0) {
+      output = output.concat([commandDescription, '']);
+    }
+
+    // Arguments
+    const argumentList = helper.visibleArguments(cmd).map((argument) => {
+      return formatItem(argument.term, argument.description);
+    });
+    if (argumentList.length > 0) {
+      output = output.concat(['Arguments:', formatList(argumentList), '']);
+    }
+
+    // Options
+    const optionList = helper.visibleOptions(cmd).map((option) => {
+      return formatItem(helper.optionTerm(option), helper.optionDescription(option));
+    });
+    if (optionList.length > 0) {
+      output = output.concat(['Options:', formatList(optionList), '']);
+    }
+
+    // Commands
+    const commandList = helper.visibleCommands(cmd).map((cmd) => {
+      return formatItem(helper.subcommandTerm(cmd), helper.subcommandDescription(cmd));
+    });
+    if (commandList.length > 0) {
+      output = output.concat(['Commands:', formatList(commandList), '']);
+    }
+
+    return output.join('\n');
+  }
+
+  /**
+   * Calculate the pad width from the maximum term length.
+   *
+   * @param {Command} cmd
+   * @param {Help} helper
+   * @returns {number}
+   */
+
+  padWidth(cmd, helper) {
+    return Math.max(
+      helper.longestOptionTermLength(cmd, helper),
+      helper.longestSubcommandTermLength(cmd, helper),
+      helper.longestArgumentTermLength(cmd, helper)
+    );
+  };
+
+  /**
+   * Wrap the given string to width characters per line, with lines after the first indented.
+   * Do not wrap if insufficient room for wrapping (minColumnWidth), or string is manually formatted.
+   *
+   * @param {string} str
+   * @param {number} width
+   * @param {number} indent
+   * @param {number} [minColumnWidth=40]
+   * @return {string}
+   *
+   */
+
+  wrap(str, width, indent, minColumnWidth = 40) {
+    // Detect manually wrapped and indented strings by searching for line breaks
+    // followed by multiple spaces/tabs.
+    if (str.match(/[\n]\s+/)) return str;
+    // Do not wrap if not enough room for a wrapped column of text (as could end up with a word per line).
+    const columnWidth = width - indent;
+    if (columnWidth < minColumnWidth) return str;
+
+    const leadingStr = str.substr(0, indent);
+    const columnText = str.substr(indent);
+
+    const indentString = ' '.repeat(indent);
+    const regex = new RegExp('.{1,' + (columnWidth - 1) + '}([\\s\u200B]|$)|[^\\s\u200B]+?([\\s\u200B]|$)', 'g');
+    const lines = columnText.match(regex) || [];
+    return leadingStr + lines.map((line, i) => {
+      if (line.slice(-1) === '\n') {
+        line = line.slice(0, line.length - 1);
+      }
+      return ((i > 0) ? indentString : '') + line.trimRight();
+    }).join('\n');
+  }
+}
+
+class Option {
+  /**
+   * Initialize a new `Option` with the given `flags` and `description`.
+   *
+   * @param {string} flags
+   * @param {string} [description]
+   */
+
+  constructor(flags, description) {
+    this.flags = flags;
+    this.description = description || '';
+
+    this.required = flags.includes('<'); // A value must be supplied when the option is specified.
+    this.optional = flags.includes('['); // A value is optional when the option is specified.
+    // variadic test ignores <value,...> et al which might be used to describe custom splitting of single argument
+    this.variadic = /\w\.\.\.[>\]]$/.test(flags); // The option can take multiple values.
+    this.mandatory = false; // The option must have a value after parsing, which usually means it must be specified on command line.
+    const optionFlags = _parseOptionFlags(flags);
+    this.short = optionFlags.shortFlag;
+    this.long = optionFlags.longFlag;
+    this.negate = false;
+    if (this.long) {
+      this.negate = this.long.startsWith('--no-');
+    }
+    this.defaultValue = undefined;
+    this.defaultValueDescription = undefined;
+    this.parseArg = undefined;
+    this.hidden = false;
+    this.argChoices = undefined;
+  }
+
+  /**
+   * Set the default value, and optionally supply the description to be displayed in the help.
+   *
+   * @param {any} value
+   * @param {string} [description]
+   * @return {Option}
+   */
+
+  default(value, description) {
+    this.defaultValue = value;
+    this.defaultValueDescription = description;
+    return this;
+  };
+
+  /**
+   * Set the custom handler for processing CLI option arguments into option values.
+   *
+   * @param {Function} [fn]
+   * @return {Option}
+   */
+
+  argParser(fn) {
+    this.parseArg = fn;
+    return this;
+  };
+
+  /**
+   * Whether the option is mandatory and must have a value after parsing.
+   *
+   * @param {boolean} [mandatory=true]
+   * @return {Option}
+   */
+
+  makeOptionMandatory(mandatory = true) {
+    this.mandatory = !!mandatory;
+    return this;
+  };
+
+  /**
+   * Hide option in help.
+   *
+   * @param {boolean} [hide=true]
+   * @return {Option}
+   */
+
+  hideHelp(hide = true) {
+    this.hidden = !!hide;
+    return this;
+  };
+
+  /**
+   * @api private
+   */
+
+  _concatValue(value, previous) {
+    if (previous === this.defaultValue || !Array.isArray(previous)) {
+      return [value];
+    }
+
+    return previous.concat(value);
+  }
+
+  /**
+   * Only allow option value to be one of choices.
+   *
+   * @param {string[]} values
+   * @return {Option}
+   */
+
+  choices(values) {
+    this.argChoices = values;
+    this.parseArg = (arg, previous) => {
+      if (!values.includes(arg)) {
+        throw new InvalidOptionArgumentError(`Allowed choices are ${values.join(', ')}.`);
+      }
+      if (this.variadic) {
+        return this._concatValue(arg, previous);
+      }
+      return arg;
+    };
+    return this;
+  };
+
+  /**
+   * Return option name.
+   *
+   * @return {string}
+   */
+
+  name() {
+    if (this.long) {
+      return this.long.replace(/^--/, '');
+    }
+    return this.short.replace(/^-/, '');
+  };
+
+  /**
+   * Return option name, in a camelcase format that can be used
+   * as a object attribute key.
+   *
+   * @return {string}
+   * @api private
+   */
+
+  attributeName() {
+    return camelcase(this.name().replace(/^no-/, ''));
+  };
+
+  /**
+   * Check if `arg` matches the short or long flag.
+   *
+   * @param {string} arg
+   * @return {boolean}
+   * @api private
+   */
+
+  is(arg) {
+    return this.short === arg || this.long === arg;
+  };
+}
+
+/**
+ * CommanderError class
+ * @class
+ */
+class CommanderError extends Error {
+  /**
+   * Constructs the CommanderError class
+   * @param {number} exitCode suggested exit code which could be used with process.exit
+   * @param {string} code an id string representing the error
+   * @param {string} message human-readable description of the error
+   * @constructor
+   */
+  constructor(exitCode, code, message) {
+    super(message);
+    // properly capture stack trace in Node.js
+    Error.captureStackTrace(this, this.constructor);
+    this.name = this.constructor.name;
+    this.code = code;
+    this.exitCode = exitCode;
+    this.nestedError = undefined;
+  }
+}
+
+/**
+ * InvalidOptionArgumentError class
+ * @class
+ */
+class InvalidOptionArgumentError extends CommanderError {
+  /**
+   * Constructs the InvalidOptionArgumentError class
+   * @param {string} [message] explanation of why argument is invalid
+   * @constructor
+   */
+  constructor(message) {
+    super(1, 'commander.invalidOptionArgument', message);
+    // properly capture stack trace in Node.js
+    Error.captureStackTrace(this, this.constructor);
+    this.name = this.constructor.name;
+  }
+}
+
+class Command extends EventEmitter {
+  /**
+   * Initialize a new `Command`.
+   *
+   * @param {string} [name]
+   */
+
+  constructor(name) {
+    super();
+    this.commands = [];
+    this.options = [];
+    this.parent = null;
+    this._allowUnknownOption = false;
+    this._allowExcessArguments = true;
+    this._args = [];
+    this.rawArgs = null;
+    this._scriptPath = null;
+    this._name = name || '';
+    this._optionValues = {};
+    this._storeOptionsAsProperties = false;
+    this._actionResults = [];
+    this._actionHandler = null;
+    this._executableHandler = false;
+    this._executableFile = null; // custom name for executable
+    this._defaultCommandName = null;
+    this._exitCallback = null;
+    this._aliases = [];
+    this._combineFlagAndOptionalValue = true;
+    this._description = '';
+    this._argsDescription = undefined;
+    this._enablePositionalOptions = false;
+    this._passThroughOptions = false;
+
+    // see .configureOutput() for docs
+    this._outputConfiguration = {
+      writeOut: (str) => process.stdout.write(str),
+      writeErr: (str) => process.stderr.write(str),
+      getOutHelpWidth: () => process.stdout.isTTY ? process.stdout.columns : undefined,
+      getErrHelpWidth: () => process.stderr.isTTY ? process.stderr.columns : undefined,
+      outputError: (str, write) => write(str)
+    };
+
+    this._hidden = false;
+    this._hasHelpOption = true;
+    this._helpFlags = '-h, --help';
+    this._helpDescription = 'display help for command';
+    this._helpShortFlag = '-h';
+    this._helpLongFlag = '--help';
+    this._addImplicitHelpCommand = undefined; // Deliberately undefined, not decided whether true or false
+    this._helpCommandName = 'help';
+    this._helpCommandnameAndArgs = 'help [command]';
+    this._helpCommandDescription = 'display help for command';
+    this._helpConfiguration = {};
+  }
+
+  /**
+   * Define a command.
+   *
+   * There are two styles of command: pay attention to where to put the description.
+   *
+   * Examples:
+   *
+   *      // Command implemented using action handler (description is supplied separately to `.command`)
+   *      program
+   *        .command('clone <source> [destination]')
+   *        .description('clone a repository into a newly created directory')
+   *        .action((source, destination) => {
+   *          console.log('clone command called');
+   *        });
+   *
+   *      // Command implemented using separate executable file (description is second parameter to `.command`)
+   *      program
+   *        .command('start <service>', 'start named service')
+   *        .command('stop [service]', 'stop named service, or all if no name supplied');
+   *
+   * @param {string} nameAndArgs - command name and arguments, args are `<required>` or `[optional]` and last may also be `variadic...`
+   * @param {Object|string} [actionOptsOrExecDesc] - configuration options (for action), or description (for executable)
+   * @param {Object} [execOpts] - configuration options (for executable)
+   * @return {Command} returns new command for action handler, or `this` for executable command
+   */
+
+  command(nameAndArgs, actionOptsOrExecDesc, execOpts) {
+    let desc = actionOptsOrExecDesc;
+    let opts = execOpts;
+    if (typeof desc === 'object' && desc !== null) {
+      opts = desc;
+      desc = null;
+    }
+    opts = opts || {};
+    const args = nameAndArgs.split(/ +/);
+    const cmd = this.createCommand(args.shift());
+
+    if (desc) {
+      cmd.description(desc);
+      cmd._executableHandler = true;
+    }
+    if (opts.isDefault) this._defaultCommandName = cmd._name;
+
+    cmd._outputConfiguration = this._outputConfiguration;
+
+    cmd._hidden = !!(opts.noHelp || opts.hidden); // noHelp is deprecated old name for hidden
+    cmd._hasHelpOption = this._hasHelpOption;
+    cmd._helpFlags = this._helpFlags;
+    cmd._helpDescription = this._helpDescription;
+    cmd._helpShortFlag = this._helpShortFlag;
+    cmd._helpLongFlag = this._helpLongFlag;
+    cmd._helpCommandName = this._helpCommandName;
+    cmd._helpCommandnameAndArgs = this._helpCommandnameAndArgs;
+    cmd._helpCommandDescription = this._helpCommandDescription;
+    cmd._helpConfiguration = this._helpConfiguration;
+    cmd._exitCallback = this._exitCallback;
+    cmd._storeOptionsAsProperties = this._storeOptionsAsProperties;
+    cmd._combineFlagAndOptionalValue = this._combineFlagAndOptionalValue;
+    cmd._allowExcessArguments = this._allowExcessArguments;
+    cmd._enablePositionalOptions = this._enablePositionalOptions;
+
+    cmd._executableFile = opts.executableFile || null; // Custom name for executable file, set missing to null to match constructor
+    this.commands.push(cmd);
+    cmd._parseExpectedArgs(args);
+    cmd.parent = this;
+
+    if (desc) return this;
+    return cmd;
+  };
+
+  /**
+   * Factory routine to create a new unattached command.
+   *
+   * See .command() for creating an attached subcommand, which uses this routine to
+   * create the command. You can override createCommand to customise subcommands.
+   *
+   * @param {string} [name]
+   * @return {Command} new command
+   */
+
+  createCommand(name) {
+    return new Command(name);
+  };
+
+  /**
+   * You can customise the help with a subclass of Help by overriding createHelp,
+   * or by overriding Help properties using configureHelp().
+   *
+   * @return {Help}
+   */
+
+  createHelp() {
+    return Object.assign(new Help(), this.configureHelp());
+  };
+
+  /**
+   * You can customise the help by overriding Help properties using configureHelp(),
+   * or with a subclass of Help by overriding createHelp().
+   *
+   * @param {Object} [configuration] - configuration options
+   * @return {Command|Object} `this` command for chaining, or stored configuration
+   */
+
+  configureHelp(configuration) {
+    if (configuration === undefined) return this._helpConfiguration;
+
+    this._helpConfiguration = configuration;
+    return this;
+  }
+
+  /**
+   * The default output goes to stdout and stderr. You can customise this for special
+   * applications. You can also customise the display of errors by overriding outputError.
+   *
+   * The configuration properties are all functions:
+   *
+   *    // functions to change where being written, stdout and stderr
+   *    writeOut(str)
+   *    writeErr(str)
+   *    // matching functions to specify width for wrapping help
+   *    getOutHelpWidth()
+   *    getErrHelpWidth()
+   *    // functions based on what is being written out
+   *    outputError(str, write) // used for displaying errors, and not used for displaying help
+   *
+   * @param {Object} [configuration] - configuration options
+   * @return {Command|Object} `this` command for chaining, or stored configuration
+   */
+
+  configureOutput(configuration) {
+    if (configuration === undefined) return this._outputConfiguration;
+
+    Object.assign(this._outputConfiguration, configuration);
+    return this;
+  }
+
+  /**
+   * Add a prepared subcommand.
+   *
+   * See .command() for creating an attached subcommand which inherits settings from its parent.
+   *
+   * @param {Command} cmd - new subcommand
+   * @param {Object} [opts] - configuration options
+   * @return {Command} `this` command for chaining
+   */
+
+  addCommand(cmd, opts) {
+    if (!cmd._name) throw new Error('Command passed to .addCommand() must have a name');
+
+    // To keep things simple, block automatic name generation for deeply nested executables.
+    // Fail fast and detect when adding rather than later when parsing.
+    function checkExplicitNames(commandArray) {
+      commandArray.forEach((cmd) => {
+        if (cmd._executableHandler && !cmd._executableFile) {
+          throw new Error(`Must specify executableFile for deeply nested executable: ${cmd.name()}`);
+        }
+        checkExplicitNames(cmd.commands);
+      });
+    }
+    checkExplicitNames(cmd.commands);
+
+    opts = opts || {};
+    if (opts.isDefault) this._defaultCommandName = cmd._name;
+    if (opts.noHelp || opts.hidden) cmd._hidden = true; // modifying passed command due to existing implementation
+
+    this.commands.push(cmd);
+    cmd.parent = this;
+    return this;
+  };
+
+  /**
+   * Define argument syntax for the command.
+   */
+
+  arguments(desc) {
+    return this._parseExpectedArgs(desc.split(/ +/));
+  };
+
+  /**
+   * Override default decision whether to add implicit help command.
+   *
+   *    addHelpCommand() // force on
+   *    addHelpCommand(false); // force off
+   *    addHelpCommand('help [cmd]', 'display help for [cmd]'); // force on with custom details
+   *
+   * @return {Command} `this` command for chaining
+   */
+
+  addHelpCommand(enableOrNameAndArgs, description) {
+    if (enableOrNameAndArgs === false) {
+      this._addImplicitHelpCommand = false;
+    } else {
+      this._addImplicitHelpCommand = true;
+      if (typeof enableOrNameAndArgs === 'string') {
+        this._helpCommandName = enableOrNameAndArgs.split(' ')[0];
+        this._helpCommandnameAndArgs = enableOrNameAndArgs;
+      }
+      this._helpCommandDescription = description || this._helpCommandDescription;
+    }
+    return this;
+  };
+
+  /**
+   * @return {boolean}
+   * @api private
+   */
+
+  _hasImplicitHelpCommand() {
+    if (this._addImplicitHelpCommand === undefined) {
+      return this.commands.length && !this._actionHandler && !this._findCommand('help');
+    }
+    return this._addImplicitHelpCommand;
+  };
+
+  /**
+   * Parse expected `args`.
+   *
+   * For example `["[type]"]` becomes `[{ required: false, name: 'type' }]`.
+   *
+   * @param {Array} args
+   * @return {Command} `this` command for chaining
+   * @api private
+   */
+
+  _parseExpectedArgs(args) {
+    if (!args.length) return;
+    args.forEach((arg) => {
+      const argDetails = {
+        required: false,
+        name: '',
+        variadic: false
+      };
+
+      switch (arg[0]) {
+        case '<':
+          argDetails.required = true;
+          argDetails.name = arg.slice(1, -1);
+          break;
+        case '[':
+          argDetails.name = arg.slice(1, -1);
+          break;
+      }
+
+      if (argDetails.name.length > 3 && argDetails.name.slice(-3) === '...') {
+        argDetails.variadic = true;
+        argDetails.name = argDetails.name.slice(0, -3);
+      }
+      if (argDetails.name) {
+        this._args.push(argDetails);
+      }
+    });
+    this._args.forEach((arg, i) => {
+      if (arg.variadic && i < this._args.length - 1) {
+        throw new Error(`only the last argument can be variadic '${arg.name}'`);
+      }
+    });
+    return this;
+  };
+
+  /**
+   * Register callback to use as replacement for calling process.exit.
+   *
+   * @param {Function} [fn] optional callback which will be passed a CommanderError, defaults to throwing
+   * @return {Command} `this` command for chaining
+   */
+
+  exitOverride(fn) {
+    if (fn) {
+      this._exitCallback = fn;
+    } else {
+      this._exitCallback = (err) => {
+        if (err.code !== 'commander.executeSubCommandAsync') {
+          throw err;
+        } else {
+          // Async callback from spawn events, not useful to throw.
+        }
+      };
+    }
+    return this;
+  };
+
+  /**
+   * Call process.exit, and _exitCallback if defined.
+   *
+   * @param {number} exitCode exit code for using with process.exit
+   * @param {string} code an id string representing the error
+   * @param {string} message human-readable description of the error
+   * @return never
+   * @api private
+   */
+
+  _exit(exitCode, code, message) {
+    if (this._exitCallback) {
+      this._exitCallback(new CommanderError(exitCode, code, message));
+      // Expecting this line is not reached.
+    }
+    process.exit(exitCode);
+  };
+
+  /**
+   * Register callback `fn` for the command.
+   *
+   * Examples:
+   *
+   *      program
+   *        .command('help')
+   *        .description('display verbose help')
+   *        .action(function() {
+   *           // output help here
+   *        });
+   *
+   * @param {Function} fn
+   * @return {Command} `this` command for chaining
+   */
+
+  action(fn) {
+    const listener = (args) => {
+      // The .action callback takes an extra parameter which is the command or options.
+      const expectedArgsCount = this._args.length;
+      const actionArgs = args.slice(0, expectedArgsCount);
+      if (this._storeOptionsAsProperties) {
+        actionArgs[expectedArgsCount] = this; // backwards compatible "options"
+      } else {
+        actionArgs[expectedArgsCount] = this.opts();
+      }
+      actionArgs.push(this);
+
+      const actionResult = fn.apply(this, actionArgs);
+      // Remember result in case it is async. Assume parseAsync getting called on root.
+      let rootCommand = this;
+      while (rootCommand.parent) {
+        rootCommand = rootCommand.parent;
+      }
+      rootCommand._actionResults.push(actionResult);
+    };
+    this._actionHandler = listener;
+    return this;
+  };
+
+  /**
+   * Factory routine to create a new unattached option.
+   *
+   * See .option() for creating an attached option, which uses this routine to
+   * create the option. You can override createOption to return a custom option.
+   *
+   * @param {string} flags
+   * @param {string} [description]
+   * @return {Option} new option
+   */
+
+  createOption(flags, description) {
+    return new Option(flags, description);
+  };
+
+  /**
+   * Add an option.
+   *
+   * @param {Option} option
+   * @return {Command} `this` command for chaining
+   */
+  addOption(option) {
+    const oname = option.name();
+    const name = option.attributeName();
+
+    let defaultValue = option.defaultValue;
+
+    // preassign default value for --no-*, [optional], <required>, or plain flag if boolean value
+    if (option.negate || option.optional || option.required || typeof defaultValue === 'boolean') {
+      // when --no-foo we make sure default is true, unless a --foo option is already defined
+      if (option.negate) {
+        const positiveLongFlag = option.long.replace(/^--no-/, '--');
+        defaultValue = this._findOption(positiveLongFlag) ? this._getOptionValue(name) : true;
+      }
+      // preassign only if we have a default
+      if (defaultValue !== undefined) {
+        this._setOptionValue(name, defaultValue);
+      }
+    }
+
+    // register the option
+    this.options.push(option);
+
+    // when it's passed assign the value
+    // and conditionally invoke the callback
+    this.on('option:' + oname, (val) => {
+      const oldValue = this._getOptionValue(name);
+
+      // custom processing
+      if (val !== null && option.parseArg) {
+        try {
+          val = option.parseArg(val, oldValue === undefined ? defaultValue : oldValue);
+        } catch (err) {
+          if (err.code === 'commander.invalidOptionArgument') {
+            const message = `error: option '${option.flags}' argument '${val}' is invalid. ${err.message}`;
+            this._displayError(err.exitCode, err.code, message);
+          }
+          throw err;
+        }
+      } else if (val !== null && option.variadic) {
+        val = option._concatValue(val, oldValue);
+      }
+
+      // unassigned or boolean value
+      if (typeof oldValue === 'boolean' || typeof oldValue === 'undefined') {
+        // if no value, negate false, and we have a default, then use it!
+        if (val == null) {
+          this._setOptionValue(name, option.negate
+            ? false
+            : defaultValue || true);
+        } else {
+          this._setOptionValue(name, val);
+        }
+      } else if (val !== null) {
+        // reassign
+        this._setOptionValue(name, option.negate ? false : val);
+      }
+    });
+
+    return this;
+  }
+
+  /**
+   * Internal implementation shared by .option() and .requiredOption()
+   *
+   * @api private
+   */
+  _optionEx(config, flags, description, fn, defaultValue) {
+    const option = this.createOption(flags, description);
+    option.makeOptionMandatory(!!config.mandatory);
+    if (typeof fn === 'function') {
+      option.default(defaultValue).argParser(fn);
+    } else if (fn instanceof RegExp) {
+      // deprecated
+      const regex = fn;
+      fn = (val, def) => {
+        const m = regex.exec(val);
+        return m ? m[0] : def;
+      };
+      option.default(defaultValue).argParser(fn);
+    } else {
+      option.default(fn);
+    }
+
+    return this.addOption(option);
+  }
+
+  /**
+   * Define option with `flags`, `description` and optional
+   * coercion `fn`.
+   *
+   * The `flags` string contains the short and/or long flags,
+   * separated by comma, a pipe or space. The following are all valid
+   * all will output this way when `--help` is used.
+   *
+   *    "-p, --pepper"
+   *    "-p|--pepper"
+   *    "-p --pepper"
+   *
+   * Examples:
+   *
+   *     // simple boolean defaulting to undefined
+   *     program.option('-p, --pepper', 'add pepper');
+   *
+   *     program.pepper
+   *     // => undefined
+   *
+   *     --pepper
+   *     program.pepper
+   *     // => true
+   *
+   *     // simple boolean defaulting to true (unless non-negated option is also defined)
+   *     program.option('-C, --no-cheese', 'remove cheese');
+   *
+   *     program.cheese
+   *     // => true
+   *
+   *     --no-cheese
+   *     program.cheese
+   *     // => false
+   *
+   *     // required argument
+   *     program.option('-C, --chdir <path>', 'change the working directory');
+   *
+   *     --chdir /tmp
+   *     program.chdir
+   *     // => "/tmp"
+   *
+   *     // optional argument
+   *     program.option('-c, --cheese [type]', 'add cheese [marble]');
+   *
+   * @param {string} flags
+   * @param {string} [description]
+   * @param {Function|*} [fn] - custom option processing function or default value
+   * @param {*} [defaultValue]
+   * @return {Command} `this` command for chaining
+   */
+
+  option(flags, description, fn, defaultValue) {
+    return this._optionEx({}, flags, description, fn, defaultValue);
+  };
+
+  /**
+  * Add a required option which must have a value after parsing. This usually means
+  * the option must be specified on the command line. (Otherwise the same as .option().)
+  *
+  * The `flags` string contains the short and/or long flags, separated by comma, a pipe or space.
+  *
+  * @param {string} flags
+  * @param {string} [description]
+  * @param {Function|*} [fn] - custom option processing function or default value
+  * @param {*} [defaultValue]
+  * @return {Command} `this` command for chaining
+  */
+
+  requiredOption(flags, description, fn, defaultValue) {
+    return this._optionEx({ mandatory: true }, flags, description, fn, defaultValue);
+  };
+
+  /**
+   * Alter parsing of short flags with optional values.
+   *
+   * Examples:
+   *
+   *    // for `.option('-f,--flag [value]'):
+   *    .combineFlagAndOptionalValue(true)  // `-f80` is treated like `--flag=80`, this is the default behaviour
+   *    .combineFlagAndOptionalValue(false) // `-fb` is treated like `-f -b`
+   *
+   * @param {Boolean} [combine=true] - if `true` or omitted, an optional value can be specified directly after the flag.
+   */
+  combineFlagAndOptionalValue(combine = true) {
+    this._combineFlagAndOptionalValue = !!combine;
+    return this;
+  };
+
+  /**
+   * Allow unknown options on the command line.
+   *
+   * @param {Boolean} [allowUnknown=true] - if `true` or omitted, no error will be thrown
+   * for unknown options.
+   */
+  allowUnknownOption(allowUnknown = true) {
+    this._allowUnknownOption = !!allowUnknown;
+    return this;
+  };
+
+  /**
+   * Allow excess command-arguments on the command line. Pass false to make excess arguments an error.
+   *
+   * @param {Boolean} [allowExcess=true] - if `true` or omitted, no error will be thrown
+   * for excess arguments.
+   */
+  allowExcessArguments(allowExcess = true) {
+    this._allowExcessArguments = !!allowExcess;
+    return this;
+  };
+
+  /**
+   * Enable positional options. Positional means global options are specified before subcommands which lets
+   * subcommands reuse the same option names, and also enables subcommands to turn on passThroughOptions.
+   * The default behaviour is non-positional and global options may appear anywhere on the command line.
+   *
+   * @param {Boolean} [positional=true]
+   */
+  enablePositionalOptions(positional = true) {
+    this._enablePositionalOptions = !!positional;
+    return this;
+  };
+
+  /**
+   * Pass through options that come after command-arguments rather than treat them as command-options,
+   * so actual command-options come before command-arguments. Turning this on for a subcommand requires
+   * positional options to have been enabled on the program (parent commands).
+   * The default behaviour is non-positional and options may appear before or after command-arguments.
+   *
+   * @param {Boolean} [passThrough=true]
+   * for unknown options.
+   */
+  passThroughOptions(passThrough = true) {
+    this._passThroughOptions = !!passThrough;
+    if (!!this.parent && passThrough && !this.parent._enablePositionalOptions) {
+      throw new Error('passThroughOptions can not be used without turning on enablePositionalOptions for parent command(s)');
+    }
+    return this;
+  };
+
+  /**
+    * Whether to store option values as properties on command object,
+    * or store separately (specify false). In both cases the option values can be accessed using .opts().
+    *
+    * @param {boolean} [storeAsProperties=true]
+    * @return {Command} `this` command for chaining
+    */
+
+  storeOptionsAsProperties(storeAsProperties = true) {
+    this._storeOptionsAsProperties = !!storeAsProperties;
+    if (this.options.length) {
+      throw new Error('call .storeOptionsAsProperties() before adding options');
+    }
+    return this;
+  };
+
+  /**
+   * Store option value
+   *
+   * @param {string} key
+   * @param {Object} value
+   * @api private
+   */
+
+  _setOptionValue(key, value) {
+    if (this._storeOptionsAsProperties) {
+      this[key] = value;
+    } else {
+      this._optionValues[key] = value;
+    }
+  };
+
+  /**
+   * Retrieve option value
+   *
+   * @param {string} key
+   * @return {Object} value
+   * @api private
+   */
+
+  _getOptionValue(key) {
+    if (this._storeOptionsAsProperties) {
+      return this[key];
+    }
+    return this._optionValues[key];
+  };
+
+  /**
+   * Parse `argv`, setting options and invoking commands when defined.
+   *
+   * The default expectation is that the arguments are from node and have the application as argv[0]
+   * and the script being run in argv[1], with user parameters after that.
+   *
+   * Examples:
+   *
+   *      program.parse(process.argv);
+   *      program.parse(); // implicitly use process.argv and auto-detect node vs electron conventions
+   *      program.parse(my-args, { from: 'user' }); // just user supplied arguments, nothing special about argv[0]
+   *
+   * @param {string[]} [argv] - optional, defaults to process.argv
+   * @param {Object} [parseOptions] - optionally specify style of options with from: node/user/electron
+   * @param {string} [parseOptions.from] - where the args are from: 'node', 'user', 'electron'
+   * @return {Command} `this` command for chaining
+   */
+
+  parse(argv, parseOptions) {
+    if (argv !== undefined && !Array.isArray(argv)) {
+      throw new Error('first parameter to parse must be array or undefined');
+    }
+    parseOptions = parseOptions || {};
+
+    // Default to using process.argv
+    if (argv === undefined) {
+      argv = process.argv;
+      // @ts-ignore: unknown property
+      if (process.versions && process.versions.electron) {
+        parseOptions.from = 'electron';
+      }
+    }
+    this.rawArgs = argv.slice();
+
+    // make it a little easier for callers by supporting various argv conventions
+    let userArgs;
+    switch (parseOptions.from) {
+      case undefined:
+      case 'node':
+        this._scriptPath = argv[1];
+        userArgs = argv.slice(2);
+        break;
+      case 'electron':
+        // @ts-ignore: unknown property
+        if (process.defaultApp) {
+          this._scriptPath = argv[1];
+          userArgs = argv.slice(2);
+        } else {
+          userArgs = argv.slice(1);
+        }
+        break;
+      case 'user':
+        userArgs = argv.slice(0);
+        break;
+      default:
+        throw new Error(`unexpected parse option { from: '${parseOptions.from}' }`);
+    }
+    if (!this._scriptPath && require.main) {
+      this._scriptPath = require.main.filename;
+    }
+
+    // Guess name, used in usage in help.
+    this._name = this._name || (this._scriptPath && path.basename(this._scriptPath, path.extname(this._scriptPath)));
+
+    // Let's go!
+    this._parseCommand([], userArgs);
+
+    return this;
+  };
+
+  /**
+   * Parse `argv`, setting options and invoking commands when defined.
+   *
+   * Use parseAsync instead of parse if any of your action handlers are async. Returns a Promise.
+   *
+   * The default expectation is that the arguments are from node and have the application as argv[0]
+   * and the script being run in argv[1], with user parameters after that.
+   *
+   * Examples:
+   *
+   *      program.parseAsync(process.argv);
+   *      program.parseAsync(); // implicitly use process.argv and auto-detect node vs electron conventions
+   *      program.parseAsync(my-args, { from: 'user' }); // just user supplied arguments, nothing special about argv[0]
+   *
+   * @param {string[]} [argv]
+   * @param {Object} [parseOptions]
+   * @param {string} parseOptions.from - where the args are from: 'node', 'user', 'electron'
+   * @return {Promise}
+   */
+
+  parseAsync(argv, parseOptions) {
+    this.parse(argv, parseOptions);
+    return Promise.all(this._actionResults).then(() => this);
+  };
+
+  /**
+   * Execute a sub-command executable.
+   *
+   * @api private
+   */
+
+  _executeSubCommand(subcommand, args) {
+    args = args.slice();
+    let launchWithNode = false; // Use node for source targets so do not need to get permissions correct, and on Windows.
+    const sourceExt = ['.js', '.ts', '.tsx', '.mjs', '.cjs'];
+
+    // Not checking for help first. Unlikely to have mandatory and executable, and can't robustly test for help flags in external command.
+    this._checkForMissingMandatoryOptions();
+
+    // Want the entry script as the reference for command name and directory for searching for other files.
+    let scriptPath = this._scriptPath;
+    // Fallback in case not set, due to how Command created or called.
+    if (!scriptPath && require.main) {
+      scriptPath = require.main.filename;
+    }
+
+    let baseDir;
+    try {
+      const resolvedLink = fs.realpathSync(scriptPath);
+      baseDir = path.dirname(resolvedLink);
+    } catch (e) {
+      baseDir = '.'; // dummy, probably not going to find executable!
+    }
+
+    // name of the subcommand, like `pm-install`
+    let bin = path.basename(scriptPath, path.extname(scriptPath)) + '-' + subcommand._name;
+    if (subcommand._executableFile) {
+      bin = subcommand._executableFile;
+    }
+
+    const localBin = path.join(baseDir, bin);
+    if (fs.existsSync(localBin)) {
+      // prefer local `./<bin>` to bin in the $PATH
+      bin = localBin;
+    } else {
+      // Look for source files.
+      sourceExt.forEach((ext) => {
+        if (fs.existsSync(`${localBin}${ext}`)) {
+          bin = `${localBin}${ext}`;
+        }
+      });
+    }
+    launchWithNode = sourceExt.includes(path.extname(bin));
+
+    let proc;
+    if (process.platform !== 'win32') {
+      if (launchWithNode) {
+        args.unshift(bin);
+        // add executable arguments to spawn
+        args = incrementNodeInspectorPort(process.execArgv).concat(args);
+
+        proc = childProcess.spawn(process.argv[0], args, { stdio: 'inherit' });
+      } else {
+        proc = childProcess.spawn(bin, args, { stdio: 'inherit' });
+      }
+    } else {
+      args.unshift(bin);
+      // add executable arguments to spawn
+      args = incrementNodeInspectorPort(process.execArgv).concat(args);
+      proc = childProcess.spawn(process.execPath, args, { stdio: 'inherit' });
+    }
+
+    const signals = ['SIGUSR1', 'SIGUSR2', 'SIGTERM', 'SIGINT', 'SIGHUP'];
+    signals.forEach((signal) => {
+      // @ts-ignore
+      process.on(signal, () => {
+        if (proc.killed === false && proc.exitCode === null) {
+          proc.kill(signal);
+        }
+      });
+    });
+
+    // By default terminate process when spawned process terminates.
+    // Suppressing the exit if exitCallback defined is a bit messy and of limited use, but does allow process to stay running!
+    const exitCallback = this._exitCallback;
+    if (!exitCallback) {
+      proc.on('close', process.exit.bind(process));
+    } else {
+      proc.on('close', () => {
+        exitCallback(new CommanderError(process.exitCode || 0, 'commander.executeSubCommandAsync', '(close)'));
+      });
+    }
+    proc.on('error', (err) => {
+      // @ts-ignore
+      if (err.code === 'ENOENT') {
+        const executableMissing = `'${bin}' does not exist
+ - if '${subcommand._name}' is not meant to be an executable command, remove description parameter from '.command()' and use '.description()' instead
+ - if the default executable name is not suitable, use the executableFile option to supply a custom name`;
+        throw new Error(executableMissing);
+      // @ts-ignore
+      } else if (err.code === 'EACCES') {
+        throw new Error(`'${bin}' not executable`);
+      }
+      if (!exitCallback) {
+        process.exit(1);
+      } else {
+        const wrappedError = new CommanderError(1, 'commander.executeSubCommandAsync', '(error)');
+        wrappedError.nestedError = err;
+        exitCallback(wrappedError);
+      }
+    });
+
+    // Store the reference to the child process
+    this.runningCommand = proc;
+  };
+
+  /**
+   * @api private
+   */
+  _dispatchSubcommand(commandName, operands, unknown) {
+    const subCommand = this._findCommand(commandName);
+    if (!subCommand) this.help({ error: true });
+
+    if (subCommand._executableHandler) {
+      this._executeSubCommand(subCommand, operands.concat(unknown));
+    } else {
+      subCommand._parseCommand(operands, unknown);
+    }
+  };
+
+  /**
+   * Process arguments in context of this command.
+   *
+   * @api private
+   */
+
+  _parseCommand(operands, unknown) {
+    const parsed = this.parseOptions(unknown);
+    operands = operands.concat(parsed.operands);
+    unknown = parsed.unknown;
+    this.args = operands.concat(unknown);
+
+    if (operands && this._findCommand(operands[0])) {
+      this._dispatchSubcommand(operands[0], operands.slice(1), unknown);
+    } else if (this._hasImplicitHelpCommand() && operands[0] === this._helpCommandName) {
+      if (operands.length === 1) {
+        this.help();
+      } else {
+        this._dispatchSubcommand(operands[1], [], [this._helpLongFlag]);
+      }
+    } else if (this._defaultCommandName) {
+      outputHelpIfRequested(this, unknown); // Run the help for default command from parent rather than passing to default command
+      this._dispatchSubcommand(this._defaultCommandName, operands, unknown);
+    } else {
+      if (this.commands.length && this.args.length === 0 && !this._actionHandler && !this._defaultCommandName) {
+        // probably missing subcommand and no handler, user needs help
+        this.help({ error: true });
+      }
+
+      outputHelpIfRequested(this, parsed.unknown);
+      this._checkForMissingMandatoryOptions();
+
+      // We do not always call this check to avoid masking a "better" error, like unknown command.
+      const checkForUnknownOptions = () => {
+        if (parsed.unknown.length > 0) {
+          this.unknownOption(parsed.unknown[0]);
+        }
+      };
+
+      const commandEvent = `command:${this.name()}`;
+      if (this._actionHandler) {
+        checkForUnknownOptions();
+        // Check expected arguments and collect variadic together.
+        const args = this.args.slice();
+        this._args.forEach((arg, i) => {
+          if (arg.required && args[i] == null) {
+            this.missingArgument(arg.name);
+          } else if (arg.variadic) {
+            args[i] = args.splice(i);
+            args.length = Math.min(i + 1, args.length);
+          }
+        });
+        if (args.length > this._args.length) {
+          this._excessArguments(args);
+        }
+
+        this._actionHandler(args);
+        if (this.parent) this.parent.emit(commandEvent, operands, unknown); // legacy
+      } else if (this.parent && this.parent.listenerCount(commandEvent)) {
+        checkForUnknownOptions();
+        this.parent.emit(commandEvent, operands, unknown); // legacy
+      } else if (operands.length) {
+        if (this._findCommand('*')) { // legacy default command
+          this._dispatchSubcommand('*', operands, unknown);
+        } else if (this.listenerCount('command:*')) {
+          // skip option check, emit event for possible misspelling suggestion
+          this.emit('command:*', operands, unknown);
+        } else if (this.commands.length) {
+          this.unknownCommand();
+        } else {
+          checkForUnknownOptions();
+        }
+      } else if (this.commands.length) {
+        // This command has subcommands and nothing hooked up at this level, so display help.
+        this.help({ error: true });
+      } else {
+        checkForUnknownOptions();
+        // fall through for caller to handle after calling .parse()
+      }
+    }
+  };
+
+  /**
+   * Find matching command.
+   *
+   * @api private
+   */
+  _findCommand(name) {
+    if (!name) return undefined;
+    return this.commands.find(cmd => cmd._name === name || cmd._aliases.includes(name));
+  };
+
+  /**
+   * Return an option matching `arg` if any.
+   *
+   * @param {string} arg
+   * @return {Option}
+   * @api private
+   */
+
+  _findOption(arg) {
+    return this.options.find(option => option.is(arg));
+  };
+
+  /**
+   * Display an error message if a mandatory option does not have a value.
+   * Lazy calling after checking for help flags from leaf subcommand.
+   *
+   * @api private
+   */
+
+  _checkForMissingMandatoryOptions() {
+    // Walk up hierarchy so can call in subcommand after checking for displaying help.
+    for (let cmd = this; cmd; cmd = cmd.parent) {
+      cmd.options.forEach((anOption) => {
+        if (anOption.mandatory && (cmd._getOptionValue(anOption.attributeName()) === undefined)) {
+          cmd.missingMandatoryOptionValue(anOption);
+        }
+      });
+    }
+  };
+
+  /**
+   * Parse options from `argv` removing known options,
+   * and return argv split into operands and unknown arguments.
+   *
+   * Examples:
+   *
+   *    argv => operands, unknown
+   *    --known kkk op => [op], []
+   *    op --known kkk => [op], []
+   *    sub --unknown uuu op => [sub], [--unknown uuu op]
+   *    sub -- --unknown uuu op => [sub --unknown uuu op], []
+   *
+   * @param {String[]} argv
+   * @return {{operands: String[], unknown: String[]}}
+   */
+
+  parseOptions(argv) {
+    const operands = []; // operands, not options or values
+    const unknown = []; // first unknown option and remaining unknown args
+    let dest = operands;
+    const args = argv.slice();
+
+    function maybeOption(arg) {
+      return arg.length > 1 && arg[0] === '-';
+    }
+
+    // parse options
+    let activeVariadicOption = null;
+    while (args.length) {
+      const arg = args.shift();
+
+      // literal
+      if (arg === '--') {
+        if (dest === unknown) dest.push(arg);
+        dest.push(...args);
+        break;
+      }
+
+      if (activeVariadicOption && !maybeOption(arg)) {
+        this.emit(`option:${activeVariadicOption.name()}`, arg);
+        continue;
+      }
+      activeVariadicOption = null;
+
+      if (maybeOption(arg)) {
+        const option = this._findOption(arg);
+        // recognised option, call listener to assign value with possible custom processing
+        if (option) {
+          if (option.required) {
+            const value = args.shift();
+            if (value === undefined) this.optionMissingArgument(option);
+            this.emit(`option:${option.name()}`, value);
+          } else if (option.optional) {
+            let value = null;
+            // historical behaviour is optional value is following arg unless an option
+            if (args.length > 0 && !maybeOption(args[0])) {
+              value = args.shift();
+            }
+            this.emit(`option:${option.name()}`, value);
+          } else { // boolean flag
+            this.emit(`option:${option.name()}`);
+          }
+          activeVariadicOption = option.variadic ? option : null;
+          continue;
+        }
+      }
+
+      // Look for combo options following single dash, eat first one if known.
+      if (arg.length > 2 && arg[0] === '-' && arg[1] !== '-') {
+        const option = this._findOption(`-${arg[1]}`);
+        if (option) {
+          if (option.required || (option.optional && this._combineFlagAndOptionalValue)) {
+            // option with value following in same argument
+            this.emit(`option:${option.name()}`, arg.slice(2));
+          } else {
+            // boolean option, emit and put back remainder of arg for further processing
+            this.emit(`option:${option.name()}`);
+            args.unshift(`-${arg.slice(2)}`);
+          }
+          continue;
+        }
+      }
+
+      // Look for known long flag with value, like --foo=bar
+      if (/^--[^=]+=/.test(arg)) {
+        const index = arg.indexOf('=');
+        const option = this._findOption(arg.slice(0, index));
+        if (option && (option.required || option.optional)) {
+          this.emit(`option:${option.name()}`, arg.slice(index + 1));
+          continue;
+        }
+      }
+
+      // Not a recognised option by this command.
+      // Might be a command-argument, or subcommand option, or unknown option, or help command or option.
+
+      // An unknown option means further arguments also classified as unknown so can be reprocessed by subcommands.
+      if (maybeOption(arg)) {
+        dest = unknown;
+      }
+
+      // If using positionalOptions, stop processing our options at subcommand.
+      if ((this._enablePositionalOptions || this._passThroughOptions) && operands.length === 0 && unknown.length === 0) {
+        if (this._findCommand(arg)) {
+          operands.push(arg);
+          if (args.length > 0) unknown.push(...args);
+          break;
+        } else if (arg === this._helpCommandName && this._hasImplicitHelpCommand()) {
+          operands.push(arg);
+          if (args.length > 0) operands.push(...args);
+          break;
+        } else if (this._defaultCommandName) {
+          unknown.push(arg);
+          if (args.length > 0) unknown.push(...args);
+          break;
+        }
+      }
+
+      // If using passThroughOptions, stop processing options at first command-argument.
+      if (this._passThroughOptions) {
+        dest.push(arg);
+        if (args.length > 0) dest.push(...args);
+        break;
+      }
+
+      // add arg
+      dest.push(arg);
+    }
+
+    return { operands, unknown };
+  };
+
+  /**
+   * Return an object containing options as key-value pairs
+   *
+   * @return {Object}
+   */
+  opts() {
+    if (this._storeOptionsAsProperties) {
+      // Preserve original behaviour so backwards compatible when still using properties
+      const result = {};
+      const len = this.options.length;
+
+      for (let i = 0; i < len; i++) {
+        const key = this.options[i].attributeName();
+        result[key] = key === this._versionOptionName ? this._version : this[key];
+      }
+      return result;
+    }
+
+    return this._optionValues;
+  };
+
+  /**
+   * Internal bottleneck for handling of parsing errors.
+   *
+   * @api private
+   */
+  _displayError(exitCode, code, message) {
+    this._outputConfiguration.outputError(`${message}\n`, this._outputConfiguration.writeErr);
+    this._exit(exitCode, code, message);
+  }
+
+  /**
+   * Argument `name` is missing.
+   *
+   * @param {string} name
+   * @api private
+   */
+
+  missingArgument(name) {
+    const message = `error: missing required argument '${name}'`;
+    this._displayError(1, 'commander.missingArgument', message);
+  };
+
+  /**
+   * `Option` is missing an argument.
+   *
+   * @param {Option} option
+   * @api private
+   */
+
+  optionMissingArgument(option) {
+    const message = `error: option '${option.flags}' argument missing`;
+    this._displayError(1, 'commander.optionMissingArgument', message);
+  };
+
+  /**
+   * `Option` does not have a value, and is a mandatory option.
+   *
+   * @param {Option} option
+   * @api private
+   */
+
+  missingMandatoryOptionValue(option) {
+    const message = `error: required option '${option.flags}' not specified`;
+    this._displayError(1, 'commander.missingMandatoryOptionValue', message);
+  };
+
+  /**
+   * Unknown option `flag`.
+   *
+   * @param {string} flag
+   * @api private
+   */
+
+  unknownOption(flag) {
+    if (this._allowUnknownOption) return;
+    const message = `error: unknown option '${flag}'`;
+    this._displayError(1, 'commander.unknownOption', message);
+  };
+
+  /**
+   * Excess arguments, more than expected.
+   *
+   * @param {string[]} receivedArgs
+   * @api private
+   */
+
+  _excessArguments(receivedArgs) {
+    if (this._allowExcessArguments) return;
+
+    const expected = this._args.length;
+    const s = (expected === 1) ? '' : 's';
+    const forSubcommand = this.parent ? ` for '${this.name()}'` : '';
+    const message = `error: too many arguments${forSubcommand}. Expected ${expected} argument${s} but got ${receivedArgs.length}.`;
+    this._displayError(1, 'commander.excessArguments', message);
+  };
+
+  /**
+   * Unknown command.
+   *
+   * @api private
+   */
+
+  unknownCommand() {
+    const partCommands = [this.name()];
+    for (let parentCmd = this.parent; parentCmd; parentCmd = parentCmd.parent) {
+      partCommands.unshift(parentCmd.name());
+    }
+    const fullCommand = partCommands.join(' ');
+    const message = `error: unknown command '${this.args[0]}'.` +
+      (this._hasHelpOption ? ` See '${fullCommand} ${this._helpLongFlag}'.` : '');
+    this._displayError(1, 'commander.unknownCommand', message);
+  };
+
+  /**
+   * Set the program version to `str`.
+   *
+   * This method auto-registers the "-V, --version" flag
+   * which will print the version number when passed.
+   *
+   * You can optionally supply the  flags and description to override the defaults.
+   *
+   * @param {string} str
+   * @param {string} [flags]
+   * @param {string} [description]
+   * @return {this | string} `this` command for chaining, or version string if no arguments
+   */
+
+  version(str, flags, description) {
+    if (str === undefined) return this._version;
+    this._version = str;
+    flags = flags || '-V, --version';
+    description = description || 'output the version number';
+    const versionOption = this.createOption(flags, description);
+    this._versionOptionName = versionOption.attributeName();
+    this.options.push(versionOption);
+    this.on('option:' + versionOption.name(), () => {
+      this._outputConfiguration.writeOut(`${str}\n`);
+      this._exit(0, 'commander.version', str);
+    });
+    return this;
+  };
+
+  /**
+   * Set the description to `str`.
+   *
+   * @param {string} [str]
+   * @param {Object} [argsDescription]
+   * @return {string|Command}
+   */
+  description(str, argsDescription) {
+    if (str === undefined && argsDescription === undefined) return this._description;
+    this._description = str;
+    this._argsDescription = argsDescription;
+    return this;
+  };
+
+  /**
+   * Set an alias for the command.
+   *
+   * You may call more than once to add multiple aliases. Only the first alias is shown in the auto-generated help.
+   *
+   * @param {string} [alias]
+   * @return {string|Command}
+   */
+
+  alias(alias) {
+    if (alias === undefined) return this._aliases[0]; // just return first, for backwards compatibility
+
+    let command = this;
+    if (this.commands.length !== 0 && this.commands[this.commands.length - 1]._executableHandler) {
+      // assume adding alias for last added executable subcommand, rather than this
+      command = this.commands[this.commands.length - 1];
+    }
+
+    if (alias === command._name) throw new Error('Command alias can\'t be the same as its name');
+
+    command._aliases.push(alias);
+    return this;
+  };
+
+  /**
+   * Set aliases for the command.
+   *
+   * Only the first alias is shown in the auto-generated help.
+   *
+   * @param {string[]} [aliases]
+   * @return {string[]|Command}
+   */
+
+  aliases(aliases) {
+    // Getter for the array of aliases is the main reason for having aliases() in addition to alias().
+    if (aliases === undefined) return this._aliases;
+
+    aliases.forEach((alias) => this.alias(alias));
+    return this;
+  };
+
+  /**
+   * Set / get the command usage `str`.
+   *
+   * @param {string} [str]
+   * @return {String|Command}
+   */
+
+  usage(str) {
+    if (str === undefined) {
+      if (this._usage) return this._usage;
+
+      const args = this._args.map((arg) => {
+        return humanReadableArgName(arg);
+      });
+      return [].concat(
+        (this.options.length || this._hasHelpOption ? '[options]' : []),
+        (this.commands.length ? '[command]' : []),
+        (this._args.length ? args : [])
+      ).join(' ');
+    }
+
+    this._usage = str;
+    return this;
+  };
+
+  /**
+   * Get or set the name of the command
+   *
+   * @param {string} [str]
+   * @return {string|Command}
+   */
+
+  name(str) {
+    if (str === undefined) return this._name;
+    this._name = str;
+    return this;
+  };
+
+  /**
+   * Return program help documentation.
+   *
+   * @param {{ error: boolean }} [contextOptions] - pass {error:true} to wrap for stderr instead of stdout
+   * @return {string}
+   */
+
+  helpInformation(contextOptions) {
+    const helper = this.createHelp();
+    if (helper.helpWidth === undefined) {
+      helper.helpWidth = (contextOptions && contextOptions.error) ? this._outputConfiguration.getErrHelpWidth() : this._outputConfiguration.getOutHelpWidth();
+    }
+    return helper.formatHelp(this, helper);
+  };
+
+  /**
+   * @api private
+   */
+
+  _getHelpContext(contextOptions) {
+    contextOptions = contextOptions || {};
+    const context = { error: !!contextOptions.error };
+    let write;
+    if (context.error) {
+      write = (arg) => this._outputConfiguration.writeErr(arg);
+    } else {
+      write = (arg) => this._outputConfiguration.writeOut(arg);
+    }
+    context.write = contextOptions.write || write;
+    context.command = this;
+    return context;
+  }
+
+  /**
+   * Output help information for this command.
+   *
+   * Outputs built-in help, and custom text added using `.addHelpText()`.
+   *
+   * @param {{ error: boolean } | Function} [contextOptions] - pass {error:true} to write to stderr instead of stdout
+   */
+
+  outputHelp(contextOptions) {
+    let deprecatedCallback;
+    if (typeof contextOptions === 'function') {
+      deprecatedCallback = contextOptions;
+      contextOptions = undefined;
+    }
+    const context = this._getHelpContext(contextOptions);
+
+    const groupListeners = [];
+    let command = this;
+    while (command) {
+      groupListeners.push(command); // ordered from current command to root
+      command = command.parent;
+    }
+
+    groupListeners.slice().reverse().forEach(command => command.emit('beforeAllHelp', context));
+    this.emit('beforeHelp', context);
+
+    let helpInformation = this.helpInformation(context);
+    if (deprecatedCallback) {
+      helpInformation = deprecatedCallback(helpInformation);
+      if (typeof helpInformation !== 'string' && !Buffer.isBuffer(helpInformation)) {
+        throw new Error('outputHelp callback must return a string or a Buffer');
+      }
+    }
+    context.write(helpInformation);
+
+    this.emit(this._helpLongFlag); // deprecated
+    this.emit('afterHelp', context);
+    groupListeners.forEach(command => command.emit('afterAllHelp', context));
+  };
+
+  /**
+   * You can pass in flags and a description to override the help
+   * flags and help description for your command. Pass in false to
+   * disable the built-in help option.
+   *
+   * @param {string | boolean} [flags]
+   * @param {string} [description]
+   * @return {Command} `this` command for chaining
+   */
+
+  helpOption(flags, description) {
+    if (typeof flags === 'boolean') {
+      this._hasHelpOption = flags;
+      return this;
+    }
+    this._helpFlags = flags || this._helpFlags;
+    this._helpDescription = description || this._helpDescription;
+
+    const helpFlags = _parseOptionFlags(this._helpFlags);
+    this._helpShortFlag = helpFlags.shortFlag;
+    this._helpLongFlag = helpFlags.longFlag;
+
+    return this;
+  };
+
+  /**
+   * Output help information and exit.
+   *
+   * Outputs built-in help, and custom text added using `.addHelpText()`.
+   *
+   * @param {{ error: boolean }} [contextOptions] - pass {error:true} to write to stderr instead of stdout
+   */
+
+  help(contextOptions) {
+    this.outputHelp(contextOptions);
+    let exitCode = process.exitCode || 0;
+    if (exitCode === 0 && contextOptions && typeof contextOptions !== 'function' && contextOptions.error) {
+      exitCode = 1;
+    }
+    // message: do not have all displayed text available so only passing placeholder.
+    this._exit(exitCode, 'commander.help', '(outputHelp)');
+  };
+
+  /**
+   * 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 {string | Function} text - string to add, or a function returning a string
+   * @return {Command} `this` command for chaining
+   */
+  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, (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;
+  }
+};
+
+/**
+ * Expose the root command.
+ */
+
+exports = module.exports = new Command();
+exports.program = exports; // More explicit access to global command.
+
+/**
+ * Expose classes
+ */
+
+exports.Command = Command;
+exports.Option = Option;
+exports.CommanderError = CommanderError;
+exports.InvalidOptionArgumentError = InvalidOptionArgumentError;
+exports.Help = Help;
+
+/**
+ * Camel-case the given `flag`
+ *
+ * @param {string} flag
+ * @return {string}
+ * @api private
+ */
+
+function camelcase(flag) {
+  return flag.split('-').reduce((str, word) => {
+    return str + word[0].toUpperCase() + word.slice(1);
+  });
+}
+
+/**
+ * Output help information if help flags specified
+ *
+ * @param {Command} cmd - command to output help for
+ * @param {Array} args - array of options to search for help flags
+ * @api private
+ */
+
+function outputHelpIfRequested(cmd, args) {
+  const helpOption = cmd._hasHelpOption && args.find(arg => arg === cmd._helpLongFlag || arg === cmd._helpShortFlag);
+  if (helpOption) {
+    cmd.outputHelp();
+    // (Do not have all displayed text available so only passing placeholder.)
+    cmd._exit(0, 'commander.helpDisplayed', '(outputHelp)');
+  }
+}
+
+/**
+ * Takes an argument and returns its human readable equivalent for help usage.
+ *
+ * @param {Object} arg
+ * @return {string}
+ * @api private
+ */
+
+function humanReadableArgName(arg) {
+  const nameOutput = arg.name + (arg.variadic === true ? '...' : '');
+
+  return arg.required
+    ? '<' + nameOutput + '>'
+    : '[' + nameOutput + ']';
+}
+
+/**
+ * Parse the short and long flag out of something like '-m,--mixed <value>'
+ *
+ * @api private
+ */
+
+function _parseOptionFlags(flags) {
+  let shortFlag;
+  let longFlag;
+  // Use original very loose parsing to maintain backwards compatibility for now,
+  // which allowed for example unintended `-sw, --short-word` [sic].
+  const flagParts = flags.split(/[ |,]+/);
+  if (flagParts.length > 1 && !/^[[<]/.test(flagParts[1])) shortFlag = flagParts.shift();
+  longFlag = flagParts.shift();
+  // Add support for lone short flag without significantly changing parsing!
+  if (!shortFlag && /^-[^-]$/.test(longFlag)) {
+    shortFlag = longFlag;
+    longFlag = undefined;
+  }
+  return { shortFlag, longFlag };
+}
+
+/**
+ * Scan arguments and increment port number for inspect calls (to avoid conflicts when spawning new command).
+ *
+ * @param {string[]} args - array of arguments from node.execArgv
+ * @returns {string[]}
+ * @api private
+ */
+
+function incrementNodeInspectorPort(args) {
+  // Testing for these options:
+  //  --inspect[=[host:]port]
+  //  --inspect-brk[=[host:]port]
+  //  --inspect-port=[host:]port
+  return args.map((arg) => {
+    if (!arg.startsWith('--inspect')) {
+      return arg;
+    }
+    let debugOption;
+    let debugHost = '127.0.0.1';
+    let debugPort = '9229';
+    let match;
+    if ((match = arg.match(/^(--inspect(-brk)?)$/)) !== null) {
+      // e.g. --inspect
+      debugOption = match[1];
+    } else if ((match = arg.match(/^(--inspect(-brk|-port)?)=([^:]+)$/)) !== null) {
+      debugOption = match[1];
+      if (/^\d+$/.test(match[3])) {
+        // e.g. --inspect=1234
+        debugPort = match[3];
+      } else {
+        // e.g. --inspect=localhost
+        debugHost = match[3];
+      }
+    } else if ((match = arg.match(/^(--inspect(-brk|-port)?)=([^:]+):(\d+)$/)) !== null) {
+      // e.g. --inspect=localhost:1234
+      debugOption = match[1];
+      debugHost = match[3];
+      debugPort = match[4];
+    }
+
+    if (debugOption && debugPort !== '0') {
+      return `${debugOption}=${debugHost}:${parseInt(debugPort) + 1}`;
+    }
+    return arg;
+  });
+}