index.js

'use strict';

var GetIntrinsic = require('es-abstract/GetIntrinsic');
var callBound = require('es-abstract/helpers/callBound');
var inspect = require('object-inspect');

var $TypeError = GetIntrinsic('%TypeError%');
var $WeakMap = GetIntrinsic('%WeakMap%', true);
var $Map = GetIntrinsic('%Map%', true);
var $push = callBound('Array.prototype.push');

var $weakMapGet = callBound('WeakMap.prototype.get', true);
var $weakMapSet = callBound('WeakMap.prototype.set', true);
var $weakMapHas = callBound('WeakMap.prototype.has', true);
var $mapGet = callBound('Map.prototype.get', true);
var $mapSet = callBound('Map.prototype.set', true);
var $mapHas = callBound('Map.prototype.has', true);
var objectGet = function (objects, key) { // eslint-disable-line consistent-return
	for (var i = 0; i < objects.length; i += 1) {
		if (objects[i].key === key) {
			return objects[i].value;
		}
	}
};
var objectSet = function (objects, key, value) {
	for (var i = 0; i < objects.length; i += 1) {
		if (objects[i].key === key) {
			objects[i].value = value; // eslint-disable-line no-param-reassign
			return;
		}
	}
	$push(objects, {
		key: key,
		value: value
	});
};
var objectHas = function (objects, key) {
	for (var i = 0; i < objects.length; i += 1) {
		if (objects[i].key === key) {
			return true;
		}
	}
	return false;
};

module.exports = function getSideChannel() {
	var $wm;
	var $m;
	var $o;
	var channel = {
		assert: function (key) {
			if (!channel.has(key)) {
				throw new $TypeError('Side channel does not contain ' + inspect(key));
			}
		},
		get: function (key) { // eslint-disable-line consistent-return
			if ($WeakMap && key && (typeof key === 'object' || typeof key === 'function')) {
				if ($wm) {
					return $weakMapGet($wm, key);
				}
			} else if ($Map) {
				if ($m) {
					return $mapGet($m, key);
				}
			} else {
				if ($o) { // eslint-disable-line no-lonely-if
					return objectGet($o, key);
				}
			}
		},
		has: function (key) {
			if ($WeakMap && key && (typeof key === 'object' || typeof key === 'function')) {
				if ($wm) {
					return $weakMapHas($wm, key);
				}
			} else if ($Map) {
				if ($m) {
					return $mapHas($m, key);
				}
			} else {
				if ($o) { // eslint-disable-line no-lonely-if
					return objectHas($o, key);
				}
			}
			return false;
		},
		set: function (key, value) {
			if ($WeakMap && key && (typeof key === 'object' || typeof key === 'function')) {
				if (!$wm) {
					$wm = new $WeakMap();
				}
				$weakMapSet($wm, key, value);
			} else if ($Map) {
				if (!$m) {
					$m = new $Map();
				}
				$mapSet($m, key, value);
			} else {
				if (!$o) {
					$o = [];
				}
				objectSet($o, key, value);
			}
		}
	};
	return channel;
};