forked from nodejs/node-core-test
-
-
Notifications
You must be signed in to change notification settings - Fork 0
/
util.js
47 lines (40 loc) · 1.04 KB
/
util.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
// https://github.com/nodejs/node/blob/3759935ee29d8042d917d3ceaa768521c14413ff/lib/internal/util.js
'use strict'
const {
ObjectCreate,
ObjectFreeze,
ReflectApply
} = require('#internal/per_context/primordials')
const {
types: { isNativeError }
} = require('util')
function createDeferredPromise () {
let _resolve
let _reject
const promise = new Promise((resolve, reject) => {
_resolve = resolve
_reject = reject
})
return { promise, resolve: _resolve, reject: _reject }
}
function isError (e) {
// An error could be an instance of Error while not being a native error
// or could be from a different realm and not be instance of Error but still
// be a native error.
return isNativeError(e) || e instanceof Error
}
function once (callback) {
let called = false
return function (...args) {
if (called) return
called = true
return ReflectApply(callback, this, args)
}
}
const kEmptyObject = ObjectFreeze(ObjectCreate(null))
module.exports = {
createDeferredPromise,
isError,
kEmptyObject,
once
}