Symbol JSON.stringify returns immediately without calling replacer fn when target is undefined

[christophercr]

Hi, first of all thanks for this nice library, it is really handy for those struggling with cross-browser compatible apps or better said IE-proof apps :p

I recently stumbled upon an issue though. It took me a bit of time to troubleshoot but here it is:

I have an app in angularjs and it uses the latest angular-ui-router. Then, in this router library there is this line of code that tries to get an stringified object passing a replacer function to ultimately log something to the console.

The problem pops up in IE11, when the core-js Symbol polyfill is used; which means that also the JSON.stringify() method is wrapped to work correctly with Symbols.

At some point, the routing library will call the JSON.stringify method passing undefined and a replacer function, and then, the wrapped JSON.stringify() function simply returns without doing anything nor even calling the replacer function.

This behaviour seems totally different in the native implementation of compliant browsers like Chrome and Firefox where the replacer function is called even if the target is undefined.

Do you think this could be refactored so that the replacer function is called?

[christophercr]

Hi @zloirock, do you think you can have a look on this issue? Is there any reason why the Symbol polyfill was implemented in that way so that the replacer function is not called?

[zloirock]

Thanks for the report, sorry for the delay.

[zloirock]

Fixed in core-js@2.5.2.

[romgar]

When I use core-js@2.5.2, I get a:

undefined is not a constructor (evaluating '$replacer.call(this, key, value)')
replacer@webpack:///~/babel-runtime/~/core-js/library/modules/es6.symbol.js:219:0 <- test_bundler.js:91356:45
replacer@webpack:///~/babel-polyfill/~/core-js/modules/es6.symbol.js:219:0 <- test_bundler.js:538:45
stringify@[native code]
stringify@webpack:///~/babel-polyfill/~/core-js/modules/es6.symbol.js:223:0 <- test_bundler.js:542:29
stringify@webpack:///~/babel-runtime/~/core-js/library/modules/es6.symbol.js:223:0 <- test_bundler.js:91360:29
stringify@webpack:///~/babel-runtime/~/core-js/library/fn/json/stringify.js:4:0 <- test_bundler.js:147023:32

triggered by a call to JSON.stringify in one of my tests.

The tests are passing properly with core-js@2.5.1.

[zloirock]

@romeovs could you provide your input data? Something like that is possible with incorrect replacer argument.

[romgar]

@zloirock Thanks for your responsiveness!
I definitely had a weird input for the replacer (JSON.stringify(data, 2, 2)), caught in some legacy code.
Do you have any idea why did it previously work? Giving a proper value for the replacer fixed the issue.

[zloirock]

@romgar fixed in core-js@2.5.3.

[romgar]

I confirm that it fixed it!
Thanks for the release and your work @zloirock !