wishthis/node_modules/d/lazy.js
2022-01-21 09:28:41 +01:00

115 lines
3.8 KiB
JavaScript

"use strict";
var isPlainFunction = require("type/plain-function/is")
, ensureValue = require("type/value/ensure")
, isValue = require("type/value/is")
, map = require("es5-ext/object/map")
, contains = require("es5-ext/string/#/contains");
var call = Function.prototype.call
, defineProperty = Object.defineProperty
, getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor
, getPrototypeOf = Object.getPrototypeOf
, hasOwnProperty = Object.prototype.hasOwnProperty
, cacheDesc = { configurable: false, enumerable: false, writable: false, value: null }
, define;
define = function (name, options) {
var value, dgs, cacheName, desc, writable = false, resolvable, flat;
options = Object(ensureValue(options));
cacheName = options.cacheName;
flat = options.flat;
if (!isValue(cacheName)) cacheName = name;
delete options.cacheName;
value = options.value;
resolvable = isPlainFunction(value);
delete options.value;
dgs = { configurable: Boolean(options.configurable), enumerable: Boolean(options.enumerable) };
if (name !== cacheName) {
dgs.get = function () {
if (hasOwnProperty.call(this, cacheName)) return this[cacheName];
cacheDesc.value = resolvable ? call.call(value, this, options) : value;
cacheDesc.writable = writable;
defineProperty(this, cacheName, cacheDesc);
cacheDesc.value = null;
if (desc) defineProperty(this, name, desc);
return this[cacheName];
};
} else if (!flat) {
dgs.get = function self() {
var ownDesc;
if (hasOwnProperty.call(this, name)) {
ownDesc = getOwnPropertyDescriptor(this, name);
// It happens in Safari, that getter is still called after property
// was defined with a value, following workarounds that
// While in IE11 it may happen that here ownDesc is undefined (go figure)
if (ownDesc) {
if (ownDesc.hasOwnProperty("value")) return ownDesc.value;
if (typeof ownDesc.get === "function" && ownDesc.get !== self) {
return ownDesc.get.call(this);
}
return value;
}
}
desc.value = resolvable ? call.call(value, this, options) : value;
defineProperty(this, name, desc);
desc.value = null;
return this[name];
};
} else {
dgs.get = function self() {
var base = this, ownDesc;
if (hasOwnProperty.call(this, name)) {
// It happens in Safari, that getter is still called after property
// was defined with a value, following workarounds that
ownDesc = getOwnPropertyDescriptor(this, name);
if (ownDesc.hasOwnProperty("value")) return ownDesc.value;
if (typeof ownDesc.get === "function" && ownDesc.get !== self) {
return ownDesc.get.call(this);
}
}
while (!hasOwnProperty.call(base, name)) base = getPrototypeOf(base);
desc.value = resolvable ? call.call(value, base, options) : value;
defineProperty(base, name, desc);
desc.value = null;
return base[name];
};
}
dgs.set = function (value) {
if (hasOwnProperty.call(this, name)) {
throw new TypeError("Cannot assign to lazy defined '" + name + "' property of " + this);
}
dgs.get.call(this);
this[cacheName] = value;
};
if (options.desc) {
desc = {
configurable: contains.call(options.desc, "c"),
enumerable: contains.call(options.desc, "e")
};
if (cacheName === name) {
desc.writable = contains.call(options.desc, "w");
desc.value = null;
} else {
writable = contains.call(options.desc, "w");
desc.get = dgs.get;
desc.set = dgs.set;
}
delete options.desc;
} else if (cacheName === name) {
desc = {
configurable: Boolean(options.configurable),
enumerable: Boolean(options.enumerable),
writable: Boolean(options.writable),
value: null
};
}
delete options.configurable;
delete options.enumerable;
delete options.writable;
return dgs;
};
module.exports = function (props) {
return map(props, function (desc, name) { return define(name, desc); });
};