nodeOptions.js

/**
  @example
    const { getNodeOptionValue } = require('nodeOptions');
    const maxOldSpaceSize = getNodeOptionValue('max_old_space_size');
 */
const parseNodeOptions = () => (!process.env.NODE_OPTIONS ? [] : process.env.NODE_OPTIONS.split(/[=:]/));

const _optionsArr = parseNodeOptions();
const _getOptionsCount = () => (_optionsArr.length ? _optionsArr.length / 2 : 0);
const _getOptionName = i => _optionsArr[i * 2];
const _getOptionValue = i => _optionsArr[(i * 2) + 1];

const nodeOptionsCount = _getOptionsCount();

const getOptionsObject = () => {
  const acc = {};
  for (let i = nodeOptionsCount - 1; i >= 0; i--) {
    acc[_getOptionName(i)] = _getOptionValue(i);
  }
  return acc;
};

const nodeOptions = getOptionsObject();

const getNodeOptionValue = id => nodeOptions[id] || nodeOptions[`--${id}`];

module.exports = {
  nodeOptions,
  nodeOptionsCount,
  getNodeOptionValue,
};