setup-python/node_modules/domexception/lib/utils.js
Danny McCormick 39c08a0eaa Initial pass
2019-06-26 21:12:00 -04:00

87 lines
2.2 KiB
JavaScript

"use strict";
// Returns "Type(value) is Object" in ES terminology.
function isObject(value) {
return typeof value === "object" && value !== null || typeof value === "function";
}
function getReferenceToBytes(bufferSource) {
// Node.js' Buffer does not allow subclassing for now, so we can get away with a prototype object check for perf.
if (Object.getPrototypeOf(bufferSource) === Buffer.prototype) {
return bufferSource;
}
if (bufferSource instanceof ArrayBuffer) {
return Buffer.from(bufferSource);
}
return Buffer.from(bufferSource.buffer, bufferSource.byteOffset, bufferSource.byteLength);
}
function getCopyToBytes(bufferSource) {
return Buffer.from(getReferenceToBytes(bufferSource));
}
function mixin(target, source) {
const keys = Object.getOwnPropertyNames(source);
for (let i = 0; i < keys.length; ++i) {
if (keys[i] in target) {
continue;
}
Object.defineProperty(target, keys[i], Object.getOwnPropertyDescriptor(source, keys[i]));
}
}
const wrapperSymbol = Symbol("wrapper");
const implSymbol = Symbol("impl");
const sameObjectCaches = Symbol("SameObject caches");
function getSameObject(wrapper, prop, creator) {
if (!wrapper[sameObjectCaches]) {
wrapper[sameObjectCaches] = Object.create(null);
}
if (prop in wrapper[sameObjectCaches]) {
return wrapper[sameObjectCaches][prop];
}
wrapper[sameObjectCaches][prop] = creator();
return wrapper[sameObjectCaches][prop];
}
function wrapperForImpl(impl) {
return impl ? impl[wrapperSymbol] : null;
}
function implForWrapper(wrapper) {
return wrapper ? wrapper[implSymbol] : null;
}
function tryWrapperForImpl(impl) {
const wrapper = wrapperForImpl(impl);
return wrapper ? wrapper : impl;
}
function tryImplForWrapper(wrapper) {
const impl = implForWrapper(wrapper);
return impl ? impl : wrapper;
}
const iterInternalSymbol = Symbol("internal");
const IteratorPrototype = Object.getPrototypeOf(Object.getPrototypeOf([][Symbol.iterator]()));
module.exports = exports = {
isObject,
getReferenceToBytes,
getCopyToBytes,
mixin,
wrapperSymbol,
implSymbol,
getSameObject,
wrapperForImpl,
implForWrapper,
tryWrapperForImpl,
tryImplForWrapper,
iterInternalSymbol,
IteratorPrototype
};