node/lib/internal/console/global.js
Joyee Cheung cfc2559ee0
console: split console into global.js and constructor.js
Since we do not actually use the Console constructor to
instantiate the global console, move the two piece of
code into two different JS files for clarity, and make
console.js a mere re-export of the global console.
The hope is to make the global console, a namespace, more
web-compatible while keeping the Console constructor
available for backwards compatibility.

PR-URL: https://github.com/nodejs/node/pull/24709
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
2018-12-02 04:51:18 +08:00

45 lines
1.6 KiB
JavaScript

'use strict';
// See https://console.spec.whatwg.org/#console-namespace
// > For historical web-compatibility reasons, the namespace object
// > for console must have as its [[Prototype]] an empty object,
// > created as if by ObjectCreate(%ObjectPrototype%),
// > instead of %ObjectPrototype%.
// Since in Node.js, the Console constructor has been exposed through
// require('console'), we need to keep the Console constructor but
// we cannot actually use `new Console` to construct the global console.
// Therefore, the console.Console.prototype is not
// in the global console prototype chain anymore.
const {
Console,
kBindStreamsLazy,
kBindProperties
} = require('internal/console/constructor');
const globalConsole = Object.create({});
// Since Console is not on the prototype chain of the global console,
// the symbol properties on Console.prototype have to be looked up from
// the global console itself. In addition, we need to make the global
// console a namespace by binding the console methods directly onto
// the global console with the receiver fixed.
for (const prop of Reflect.ownKeys(Console.prototype)) {
if (prop === 'constructor') { continue; }
const desc = Reflect.getOwnPropertyDescriptor(Console.prototype, prop);
if (typeof desc.value === 'function') { // fix the receiver
desc.value = desc.value.bind(globalConsole);
}
Reflect.defineProperty(globalConsole, prop, desc);
}
globalConsole[kBindStreamsLazy](process);
globalConsole[kBindProperties](true, 'auto');
// This is a legacy feature - the Console constructor is exposed on
// the global console instance.
globalConsole.Console = Console;
module.exports = globalConsole;