mirror of
https://github.com/nodejs/node.git
synced 2026-11-09 15:11:11 -05:00
Rich Trott
d7aa8fa088
Update ESLint to 2.1.0. ESLint has a number of potentially-useful new features but this change attempts to be minimal in its changes. However, some things could not be avoided reasonably. ESLint 2.1.0 found a few lint issues that ESLing 1.x missed with template strings that did not take advantage of any features of template strings, and `let` declarations where `const` sufficed. Additionally, ESLint 2.1.0 removes some granularity around enabling ES6 features. Some features (e.g., spread operator) that had been turned off in our configuration for ESLint 1.x are now permitted. PR-URL: https://github.com/nodejs/node/pull/5214 Reviewed-By: Michaël Zasso <mic.besace@gmail.com> Reviewed-By: jbergstroem - Johan Bergström <bugs@bergstroem.nu> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Roman Reiss <me@silverwind.io> Reviewed-By: Myles Borins <myles.borins@gmail.com>
once
Only call a function once.
usage
var once = require('once')
function load (file, cb) {
cb = once(cb)
loader.load('file')
loader.once('load', cb)
loader.once('error', cb)
}
Or add to the Function.prototype in a responsible way:
// only has to be done once
require('once').proto()
function load (file, cb) {
cb = cb.once()
loader.load('file')
loader.once('load', cb)
loader.once('error', cb)
}
Ironically, the prototype feature makes this module twice as complicated as necessary.
To check whether you function has been called, use fn.called. Once the
function is called for the first time the return value of the original
function is saved in fn.value and subsequent calls will continue to
return this value.
var once = require('once')
function load (cb) {
cb = once(cb)
var stream = createStream()
stream.once('data', cb)
stream.once('end', function () {
if (!cb.called) cb(new Error('not found'))
})
}