Trying to call toString method on null in _tryDefineProperty method

[DenisKozko]

In _tryDefineProperty if JSON.stringify(desc) fails, null.toString is calling. I got this problem in IE11, when I commented this descJson = descJson.toString(); my app worked

                var descJson = null;
                try {
                    descJson = JSON.stringify(desc);
                }
                catch (error) {
                    descJson = descJson.toString();
                }
                console.log("Attempting to configure '" + prop + "' with descriptor '" + descJson + "' on object '" + obj + "' and got error, giving up: " + error);
            }```

[JiaLiPassion]

@DenisKozko , thank you for reporting the issue, could you tell me the case when desc can't be JSON.stringify.

[DenisKozko]

I think it's just a logic error here, but if you really need an example I can give you screen from my IE console. I log first 3 params of this method.

Hope it will help you. If you need more info you can ask me
Please note that log in the bottom is the result when I commented descJson = descJson.toString();

[JiaLiPassion]

@DenisKozko , ok, thank you, I will add check to avoid this error.

[DenisKozko]

@JiaLiPassion
Can you please tell me when this fix will be in angular master?

[JiaLiPassion]

@DenisKozko , I am not sure, you can used the attached zone.zip to replace node_modules\zone.js\dist for now.
zone.zip

[mhadaily]

@JiaLiPassion I am getting this error Function.prototype.toString: 'this' is not a Function object, I tried to update with your the zip files that you had sent. but it's still getting this error.

I used this flag #933 which you have mentioned __Zone_enable_cross_context_check = true;, that makes the app to work again, however, dom will not get updated correctly, unfortunately. means change detection in Angular will not continue working properly.

@JiaLiPassion FYI, this issue is happening only when the CLI flag is --pord, There is no issue in the development environment which I guess uglifying or minifying is making this problem.

1- Angular 5
2- CLI 1.5
3- zone 0.8.18

The issue is on IE11.

[JiaLiPassion]

@mhadaily , could you provide a reproduce repo?

[mhadaily]

@JiaLiPassion Sorry, ignore, the issue actually was at Swiper.js library and their new esm module.