| var global = require('./_global'); |
| var macrotask = require('./_task').set; |
| var Observer = global.MutationObserver || global.WebKitMutationObserver; |
| var process = global.process; |
| var Promise = global.Promise; |
| var isNode = require('./_cof')(process) == 'process'; |
| |
| module.exports = function () { |
| var head, last, notify; |
| |
| var flush = function () { |
| var parent, fn; |
| if (isNode && (parent = process.domain)) parent.exit(); |
| while (head) { |
| fn = head.fn; |
| head = head.next; |
| try { |
| fn(); |
| } catch (e) { |
| if (head) notify(); |
| else last = undefined; |
| throw e; |
| } |
| } last = undefined; |
| if (parent) parent.enter(); |
| }; |
| |
| // Node.js |
| if (isNode) { |
| notify = function () { |
| process.nextTick(flush); |
| }; |
| // browsers with MutationObserver, except iOS Safari - https://github.com/zloirock/core-js/issues/339 |
| } else if (Observer && !(global.navigator && global.navigator.standalone)) { |
| var toggle = true; |
| var node = document.createTextNode(''); |
| new Observer(flush).observe(node, { characterData: true }); // eslint-disable-line no-new |
| notify = function () { |
| node.data = toggle = !toggle; |
| }; |
| // environments with maybe non-completely correct, but existent Promise |
| } else if (Promise && Promise.resolve) { |
| var promise = Promise.resolve(); |
| notify = function () { |
| promise.then(flush); |
| }; |
| // for other environments - macrotask based on: |
| // - setImmediate |
| // - MessageChannel |
| // - window.postMessag |
| // - onreadystatechange |
| // - setTimeout |
| } else { |
| notify = function () { |
| // strange IE + webpack dev server bug - use .call(global) |
| macrotask.call(global, flush); |
| }; |
| } |
| |
| return function (fn) { |
| var task = { fn: fn, next: undefined }; |
| if (last) last.next = task; |
| if (!head) { |
| head = task; |
| notify(); |
| } last = task; |
| }; |
| }; |