devsite/node_modules/promise/domains/node-extensions.js
2024-07-07 18:49:38 -07:00

131 lines
3.2 KiB
JavaScript

'use strict';
// This file contains then/promise specific extensions that are only useful
// for node.js interop
var Promise = require('./core.js');
var asap = require('asap');
module.exports = Promise;
/* Static Functions */
Promise.denodeify = function (fn, argumentCount) {
if (
typeof argumentCount === 'number' && argumentCount !== Infinity
) {
return denodeifyWithCount(fn, argumentCount);
} else {
return denodeifyWithoutCount(fn);
}
};
var callbackFn = (
'function (err, res) {' +
'if (err) { rj(err); } else { rs(res); }' +
'}'
);
function denodeifyWithCount(fn, argumentCount) {
var args = [];
for (var i = 0; i < argumentCount; i++) {
args.push('a' + i);
}
var body = [
'return function (' + args.join(',') + ') {',
'var self = this;',
'return new Promise(function (rs, rj) {',
'var res = fn.call(',
['self'].concat(args).concat([callbackFn]).join(','),
');',
'if (res &&',
'(typeof res === "object" || typeof res === "function") &&',
'typeof res.then === "function"',
') {rs(res);}',
'});',
'};'
].join('');
return Function(['Promise', 'fn'], body)(Promise, fn);
}
function denodeifyWithoutCount(fn) {
var fnLength = Math.max(fn.length - 1, 3);
var args = [];
for (var i = 0; i < fnLength; i++) {
args.push('a' + i);
}
var body = [
'return function (' + args.join(',') + ') {',
'var self = this;',
'var args;',
'var argLength = arguments.length;',
'if (arguments.length > ' + fnLength + ') {',
'args = new Array(arguments.length + 1);',
'for (var i = 0; i < arguments.length; i++) {',
'args[i] = arguments[i];',
'}',
'}',
'return new Promise(function (rs, rj) {',
'var cb = ' + callbackFn + ';',
'var res;',
'switch (argLength) {',
args.concat(['extra']).map(function (_, index) {
return (
'case ' + (index) + ':' +
'res = fn.call(' + ['self'].concat(args.slice(0, index)).concat('cb').join(',') + ');' +
'break;'
);
}).join(''),
'default:',
'args[argLength] = cb;',
'res = fn.apply(self, args);',
'}',
'if (res &&',
'(typeof res === "object" || typeof res === "function") &&',
'typeof res.then === "function"',
') {rs(res);}',
'});',
'};'
].join('');
return Function(
['Promise', 'fn'],
body
)(Promise, fn);
}
Promise.nodeify = function (fn) {
return function () {
var args = Array.prototype.slice.call(arguments);
var callback =
typeof args[args.length - 1] === 'function' ? args.pop() : null;
var ctx = this;
try {
return fn.apply(this, arguments).nodeify(callback, ctx);
} catch (ex) {
if (callback === null || typeof callback == 'undefined') {
return new Promise(function (resolve, reject) {
reject(ex);
});
} else {
asap(function () {
callback.call(ctx, ex);
})
}
}
}
};
Promise.prototype.nodeify = function (callback, ctx) {
if (typeof callback != 'function') return this;
this.then(function (value) {
asap(function () {
callback.call(ctx, null, value);
});
}, function (err) {
asap(function () {
callback.call(ctx, err);
});
});
};