Function.prototype.bind is undefined

[kpozin]

kpozin@gmail.com commented:

Which version of PhantomJS are you using? Tip: run 'phantomjs --version'.
1.5.1 (development)

What steps will reproduce the problem?

1. Run phantomjs in REPL mode.
2. Type "Function.prototype.bind" and hit Return

What is the expected output? What do you see instead?
Expected: "[Function]"
Actual: undefined

Which operating system are you using?
Win 7 x64

Did you use binary PhantomJS or did you compile it from source?
Binary

Please provide any additional information below.
Function.prototype.bind is also undefined when running scripts (non in REPL mode).

Disclaimer:
This issue was migrated on 2013-03-15 from the project's former issue tracker on Google Code, Issue #522.
🌟   24 people had starred this issue at the time of migration.

[kpozin]

kpozin@gmail.com commented:

Looks like this is failing because PhantomJS is built with an old version of JavaScriptCore that is missing the "bind" implementation.

[ariya]

j...@thereitis.com commented:

Reproduced issue with version 1.6.0, Mac OS X 10.7.4, compiled from source.

[creationix]

t...@creationix.com commented:

I was just bit by this bug too. We have crazy new stuff like DataView and binary websockets, but we don't have basic ES5 functions!?

phantomjs 1.6.1 on Ubuntu 12.04 x64

[creationix]

t...@creationix.com commented:

I take back what I said about binary websockets. That doesn't appear to work. Sorry for the confusion.

[yanfalies]

yanf...@edgespring.com commented:

Worked around it with a polyfill https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/Function/bind

[ariya]

ariya.hi...@gmail.com commented:

This is likely solved once we fix issue #10031 (update WebKit).

[ariya]

bradwill...@gmail.com commented:

I hit this issue too, still in 1.8

[tupton]

Is there a current workaround for this while we wait for #10031? Simply creating a shim in my phantom runner script using this code from MDN doesn't seem to apply to the Function object that phantomjs uses. Is there somewhere else I should be trying to insert this shim?

[creationix]

@tupton When I created a Function.prototype.bind polyfill, it worked fine for me. https://github.com/c9/smith/blob/master/tests/public/test.js#L2-L7

[tupton]

@creationix Thanks for that pointer. I'm extremely new to phantomjs and still trying to figure out everything in context. I was trying to define Function.prototype.bind in my actual phantom script, not in my tests or test page. Moving it to my test runner page worked.

[molily]

“Why PhantomJS doesn't have Function.prototype.bind” by @ariya: https://groups.google.com/forum/#!msg/phantomjs/r0hPOmnCUpc/uxusqsl2LNoJ

[ariya]

My long explanation is posted in https://groups.google.com/forum/#!msg/phantomjs/r0hPOmnCUpc/uxusqsl2LNoJ.

The summary:

We never intended this to happen. PhantomJS relies on QtWebKit in Qt and the last stable version of Qt (which has updated QtWebKit) was slow to emerge (for a lot of technical and non-technical reasons).

We already tried some attempts to rectify the situation. Unfortunately it's a lot of work and all the combined spare-time of our contributors is not enough to bring the solution to the table.

[jfirebaugh]

@ariya, thank you for your hard work, and thanks to the other volunteers. Your efforts are much appreciated. The long explanation helps.

With respect to the port to Qt 5, where does that get us exactly? How fresh is its fresher QtWebKit?

[ariya]

For Qt 5 stuff, please track issue #10448. It's too early to say but what I can confirm is that bind is there.

[matenadasdi]

Hi,

Are there any news on this?

This polyfill can handle the issue, but it would be great if we could get a newer JS Core in PHJS:)

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/bind?redirectlocale=en-US&redirectslug=JavaScript%2FReference%2FGlobal_Objects%2FFunction%2Fbind

[mitar]

For me polyfill didn't work. But underscore's bind did.

[KKrisu]

I have added mentioned shim, but
console.log.bind(console);
still didn't work, so I've also added this reference:
if(!console.log.bind) { console.log.bind = Function.prototype.bind; }
And now it works! :)

[frankcortes]

In my case I can replace native bind() for Underscore's bind and works properly.

[andreaugusto]

Extracted from @creationix post. The full solution is here:

// PhantomJS doesn't support bind yet
Function.prototype.bind = Function.prototype.bind || function (thisp) {
    var fn = this;
    return function () {
        return fn.apply(thisp, arguments);
    };
}; 

Append this on top of your tests and it will fix the issue.

Worked like a charm for me. Thank you!

[JamesMGreene]

@andreaugusto / @creationix:
That polyfill will support the most common usage of bind (binding the context argument) in whatever single scope it is executed, which may be all that some users need.

However, there are also a number of shortcomings with this workaround that will prevent from working for everyone's needs:

• It is an incomplete implementation of bind (missing argument currying/binding, for example)
• It adds a new enumerable property to Function.prototype
• It must exist in every context and every page load/navigation prior to JS execution: PhantomJS outer context, WebPage instances' client context, child windows, child frames, child iframes, etc.

The first two can be addressed with a better polyfill implementation (Mozilla's MDN one is pretty good). However, the third seems to be elusive despite our having creates various hooks into the page lifecycle(s).

[benlesh]

@andreaugusto, you might wish to use the polyfill from MDN which is more complete, but lists its caveats.

[mitar]

For me polyfill from MDN didn't work well in all cases, but underscore _.bind did.

[amercier]

Any chances to see this fixed? PhantomJS seems to be the last browser not to support Function.prototype.bind.

By the way, if you are using Bower, bind-polyfill by @kdimatteo provides Mozilla's MDN polyfill:

bower install bind-polyfill

[vitallium]

@amercier, This issue is fixed in PhantomJS 2 :)