Zone.js hangs on Meteor env

[ardatan]

Due to Meteor's restriction of 'patchThen' issue, it was fixed to force patching by change property of writable to true.
#851
In Meteor 1.6, 'then' should not patch in case of writable : false, because it causes hanging.
I think fix should be like

var prop = Object.getOwnPropertyDescriptor(Ctor.prototype, 'then');
if (prop && prop.writable !== false) {
 Ctor.prototype.then = function (onResolve, onReject) {
 var _this = this;
 var wrapped = new ZoneAwarePromise(function (resolve, reject) {
 originalThen.call(_this, resolve, reject);
 });
 return wrapped.then(onResolve, onReject);
 };
}

This fix is important for new version of Angular Meteor. I hope you will be interested in. Thanks.

[JiaLiPassion]

@ardatan , could you describe a little more about hanging, you mean with #851, if the writable is changed to true, it will hang because of zone patched then?

[ardatan]

Meteor uses Fibers by patching Promise.then as well, then change 'writable' false. After that, zone.js patches Promise( by forcing to make it writable ).
Application freezes in case of use of Promise.
However, if zone.js doesn't patch Promise.then, it works well.

[JiaLiPassion]

@ardatan , I am not familiar with Meteor, if zone.js doesn't patch Promise.then, Promise will not trigger any ZoneSpec callback, so angular will not work as expected (such as change detection).

[ardatan]

Angular already calls ZoneAwarePromise in application. Btw, this is only for server-side rendering, and it works correctly if we do not overwrite 'prototype.then'.
So it will be safe to change code like I mentioned before in my opinion.

[apatryda-instapage]

I can confirm that the patch sugested by @ardatan fixes meteor backend issues with zone.js