'use strict';

/**

* Some settings and code related to Mocha's handling of Node.js/V8 flags.
* @private
* @module
*/

const nodeFlags = require('node-environment-flags'); const unparse = require('yargs-unparser');

/**

* These flags are considered "debug" flags.
* @see {@link impliesNoTimeouts}
* @private
*/

const debugFlags = new Set(['debug', 'debug-brk', 'inspect', 'inspect-brk']);

/**

* Mocha has historical support for various `node` and V8 flags which might not
* appear in `process.allowedNodeEnvironmentFlags`.
* These include:
*   - `--preserve-symlinks`
*   - `--harmony-*`
*   - `--gc-global`
*   - `--trace-*`
*   - `--es-staging`
*   - `--use-strict`
*   - `--v8-*` (but *not* `--v8-options`)
* @summary Whether or not to pass a flag along to the `node` executable.
* @param {string} flag - Flag to test
* @param {boolean} [bareword=true] - If `false`, we expect `flag` to have one or two leading dashes.
* @returns {boolean} If the flag is considered a "Node" flag.
* @private
*/

exports.isNodeFlag = (flag, bareword = true) => {

if (!bareword) {
  // check if the flag begins with dashes; if not, not a node flag.
  if (!/^--?/.test(flag)) {
    return false;
  }
  // strip the leading dashes to match against subsequent checks
  flag = flag.replace(/^--?/, '');
}
return (
  // treat --require/-r as Mocha flag even though it's also a node flag
  !(flag === 'require' || flag === 'r') &&
  // check actual node flags from `process.allowedNodeEnvironmentFlags`,
  // then historical support for various V8 and non-`NODE_OPTIONS` flags
  // and also any V8 flags with `--v8-` prefix
  (nodeFlags.has(flag) ||
    debugFlags.has(flag) ||
    /(?:preserve-symlinks(?:-main)?|harmony(?:[_-]|$)|(?:trace[_-].+$)|gc(?:[_-]global)?$|es[_-]staging$|use[_-]strict$|v8[_-](?!options).+?$)/.test(
      flag
    ))
);

};

/**

* Returns `true` if the flag is a "debug-like" flag.  These require timeouts
* to be suppressed, or pausing the debugger on breakpoints will cause test failures.
* @param {string} flag - Flag to test
* @returns {boolean}
* @private
*/

exports.impliesNoTimeouts = flag => debugFlags.has(flag);

/**

* All non-strictly-boolean arguments to node--those with values--must specify those values using `=`, e.g., `--inspect=0.0.0.0`.
* Unparse these arguments using `yargs-unparser` (which would result in `--inspect 0.0.0.0`), then supply `=` where we have values.
* There's probably an easier or more robust way to do this; fixes welcome
* @param {Object} opts - Arguments object
* @returns {string[]} Unparsed arguments using `=` to specify values
* @private
*/

exports.unparseNodeFlags = opts => {

var args = unparse(opts);
return args.length
  ? args
      .join(' ')
      .split(/\b/)
      .map(arg => (arg === ' ' ? '=' : arg))
      .join('')
      .split(' ')
  : [];

};