[bug] `new Function` string tag is "global" and prototype methods like `.bind()` are missing.

[trusktr]

I've got a weird issue. First, notice the weird output in the following screenshot, where temp1 is a function created with new Function(...):

The string tag appears to be "global" (hence [object global] output) and .bind() is missing!

To reproduce, check out the following repo on the following branch: https://github.com/trusktr/lowclass/tree/nodejs-issue-19651

After cloning and checking out the branch, just run node test.js (there's no dependencies to install) which will result in the output:

> node test.js
es5 mode
es5 mode
about to call super constructor in Dog
WTF? [object global] function false
/home/trusktr/Downloads/src/trusktr+lowclass/src/index.js:387
                descriptor.value = descriptor.value.bind( instance )
                                                    ^

TypeError: descriptor.value.bind is not a function
    at copyDescriptors (/home/trusktr/Downloads/src/trusktr+lowclass/src/index.js:387:53)
    at copyDescriptors (/home/trusktr/Downloads/src/trusktr+lowclass/src/index.js:352:18)
    at getSuperHelperObject (/home/trusktr/Downloads/src/trusktr+lowclass/src/index.js:383:9)
    at superHelper (/home/trusktr/Downloads/src/trusktr+lowclass/src/index.js:368:16)
    at Dog.constructor (/home/trusktr/Downloads/src/trusktr+lowclass/test.js:28:13)
    at new Dog (eval at Class (/home/trusktr/Downloads/src/trusktr+lowclass/src/index.js:135:20), <anonymous>:30:54)
    at Object.<anonymous> (/home/trusktr/Downloads/src/trusktr+lowclass/test.js:35:15)
    at Module._compile (module.js:649:30)
    at Object.Module._extensions..js (module.js:660:10)
    at Module.load (module.js:561:32)

If you look at line 10 of test.js, and make uncomment line 10 and comment the next lines so it look like the following then the error goes away:

    const Clazz = Class
    //const Clazz = Class.configure({
        //mode: 'es5',
        ////mode: 'Reflect.construct',
    //})

So the error is somehow related to the Class.configure call, but I haven't found why though.

As far as I know, I'm not messing with Function.prototype, so I don't see how .bind() could possibly be missing from the function that I am creating. Have I missed something obvious, or is this a bug?

[targos]

It's because of this line: https://github.com/trusktr/lowclass/blob/3854ad9d5f9178afa97c59de08d0909591fa1de0/src/index.js#L176

NewClass.__proto__ = ParentClass; // static inheritance

ParentClass is the global object, so the Animal constructor, while being a function, will lose Function.prototype methods there and inherit toString from Object.prototype

[TimothyGu]

Quick analysis:

_Class.configure returns a function defined by

    return function( ...args ) {
        return Class.call( this, options, ...args )
    }

This returned function is stored in Clazz. test.js then calls that function in the global scope (const Animal = Clazz(...)), so this is set to global when Clazz is called. This is then reflected in the Class function defined in index.js which has const ParentClass = this || Object, where this is global.

On the other hand, when const Clazz = Class, Class refers to the _Class function in index.js, and there isn't the Class.call(this) in that function. So the Class is undefined when it is called by _Class.

Next time, please make sure file this type of issues at nodejs/help when it's not clear that there is a bug in Node.js.

[trusktr]

file this type of issues at nodejs/help

Will do. Sorry about that. I see it now, I forgot a "use strict" in there. Many thanks!

[trusktr]

I forgot a "use strict" in there.