81 lines
2.2 KiB
JavaScript
81 lines
2.2 KiB
JavaScript
|
|
||
|
|
var Promise = require('any-promise')
|
||
|
|
var assert = require('assert')
|
||
|
|
|
||
|
|
module.exports = thenify
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Turn async functions into promises
|
||
|
|
*
|
||
|
|
* @param {Function} $$__fn__$$
|
||
|
|
* @return {Function}
|
||
|
|
* @api public
|
||
|
|
*/
|
||
|
|
|
||
|
|
function thenify($$__fn__$$, options) {
|
||
|
|
assert(typeof $$__fn__$$ === 'function')
|
||
|
|
return eval(createWrapper($$__fn__$$.name, options))
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Turn async functions into promises and backward compatible with callback
|
||
|
|
*
|
||
|
|
* @param {Function} $$__fn__$$
|
||
|
|
* @return {Function}
|
||
|
|
* @api public
|
||
|
|
*/
|
||
|
|
|
||
|
|
thenify.withCallback = function ($$__fn__$$, options) {
|
||
|
|
assert(typeof $$__fn__$$ === 'function')
|
||
|
|
options = options || {}
|
||
|
|
options.withCallback = true
|
||
|
|
if (options.multiArgs === undefined) options.multiArgs = true
|
||
|
|
return eval(createWrapper($$__fn__$$.name, options))
|
||
|
|
}
|
||
|
|
|
||
|
|
function createCallback(resolve, reject, multiArgs) {
|
||
|
|
return function(err, value) {
|
||
|
|
if (err) return reject(err)
|
||
|
|
var length = arguments.length
|
||
|
|
|
||
|
|
if (length <= 2 || !multiArgs) return resolve(value)
|
||
|
|
|
||
|
|
if (Array.isArray(multiArgs)) {
|
||
|
|
var values = {}
|
||
|
|
for (var i = 1; i < length; i++) values[multiArgs[i - 1]] = arguments[i]
|
||
|
|
return resolve(values)
|
||
|
|
}
|
||
|
|
|
||
|
|
var values = new Array(length - 1)
|
||
|
|
for (var i = 1; i < length; ++i) values[i - 1] = arguments[i]
|
||
|
|
resolve(values)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
function createWrapper(name, options) {
|
||
|
|
name = (name || '').replace(/\s|bound(?!$)/g, '')
|
||
|
|
options = options || {}
|
||
|
|
// default to true
|
||
|
|
var multiArgs = options.multiArgs !== undefined ? options.multiArgs : true
|
||
|
|
multiArgs = 'var multiArgs = ' + JSON.stringify(multiArgs) + '\n'
|
||
|
|
|
||
|
|
var withCallback = options.withCallback ?
|
||
|
|
'var lastType = typeof arguments[len - 1]\n'
|
||
|
|
+ 'if (lastType === "function") return $$__fn__$$.apply(self, arguments)\n'
|
||
|
|
: ''
|
||
|
|
|
||
|
|
return '(function ' + name + '() {\n'
|
||
|
|
+ 'var self = this\n'
|
||
|
|
+ 'var len = arguments.length\n'
|
||
|
|
+ multiArgs
|
||
|
|
+ withCallback
|
||
|
|
+ 'var args = new Array(len + 1)\n'
|
||
|
|
+ 'for (var i = 0; i < len; ++i) args[i] = arguments[i]\n'
|
||
|
|
+ 'var lastIndex = i\n'
|
||
|
|
+ 'return new Promise(function (resolve, reject) {\n'
|
||
|
|
+ 'args[lastIndex] = createCallback(resolve, reject, multiArgs)\n'
|
||
|
|
+ '$$__fn__$$.apply(self, args)\n'
|
||
|
|
+ '})\n'
|
||
|
|
+ '})'
|
||
|
|
}
|