makeAddListener breaks when the Event Name is a Symbol

[jreidgreer]

When Zone.js is running in Node, it appears to be wrapping Node's EventEmitter methods, causing issues when the eventName is a Symbol. Node's documentation states that eventName can be a string or a symbol.

However, Zone tries to coerce eventName into a string:

zone.js/lib/common/events.ts

Line 383 in e9536ec

const falseEventName = eventName + FALSE_STR;

This causes an error:

TypeError: Cannot convert a Symbol value to a string
    at Unpack.<anonymous> (zone.js/dist/zone-node.js:1688:52)
    at new Parser (/gulp-custom-plugin/node_modules/custom-module/node_modules/tar/lib/parse.js:70:12)
    at new <anonymous> (/gulp-custom-plugin/node_modules/custom-module/node_modules/tar/lib/warn-mixin.js:2:26)
    at new Unpack (/gulp-custom-plugin/node_modules/custom-module/node_modules/tar/lib/unpack.js:52:5)
    at extract (/gulp-custom-plugin/node_modules/custom-module/node_modules/tar/lib/extract.js:111:10)
    at Object.module.exports (/gulp-custom-plugin/node_modules/custom-module/node_modules/tar/lib/extract.js:38:7)
    at extractStream (/gulp-custom-plugin/node_modules/custom-module/node_modules/pacote/lib/extract-stream.js:39:1

This is causing an issue in the node-tar library, for instance.

[JiaLiPassion]

@jreidgreer , thank you for posting the issue, I will fix this one.

[Mathyn]

Is a fix already available? I am also running into issues using node-tar with zone.js. I use zone.js version 0.8.26.

[alamothe]

Running into this issue after upgrading puppeteer to 1.10, is there a fix?

EDIT: Downgrade to puppeteer 1.8 fixes it.

[JiaLiPassion]

@alamothe, it is fixed, but not merged yet, please wait for the next release(not sure when...)

[jreidgreer]

@Mathyn @alamothe you can prevent this issue if you place this before Zone bootstraps:

global.__Zone_disable_EventEmitter = true;

Obviously not idea, but it'll do the trick.

[alamothe]

Does it have any side-effect...?

[JiaLiPassion]

@alamothe, the side-effect will be the callback of addListener(eventName, callback) will not under the control of zone.js, so it will outside of zone. if you are working on something relying on it (such as Change detection in Electron), it will not work.

[alamothe]

No worries, in my case I'm fine with puppeteer 1.8 for now and will wait for the next release. Thanks!