jacomyal/README.md

## README.md

      
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              README.md
            
          
    I met an issue with the common polyfill for Function.prototype.bind, found on the MDN, and I do not know where to fix it.
Here is the polyfill:
if (!Function.prototype.bind) {
  Function.prototype.bind = function(oThis) {
    if (typeof this !== 'function') {
      // closest thing possible to the ECMAScript 5
      // internal IsCallable function
      throw new TypeError('Function.prototype.bind - what is trying to be bound is not callable');
    }

    var aArgs   = Array.prototype.slice.call(arguments, 1),
        fToBind = this,
        fNOP    = function() {},
        fBound  = function() {
          return fToBind.apply(this instanceof fNOP && oThis
                 ? this
                 : oThis,
                 aArgs.concat(Array.prototype.slice.call(arguments)));
        };

    fNOP.prototype = this.prototype;
    fBound.prototype = new fNOP();

    return fBound;
  };
}
Context

I was trying to unit test some React components usign a Mocha / PhantomJS wrapper for Gulp. This gulp task uses PhantomJS v1.9, that does not have Function.prototype.bind support (source). And Function.prototype.bind is used some times in React source code, so I used the polyfill.
The issue

When I ran my script, I received the following error:
TypeError: instanceof called on an object with an invalid prototype property.

After some investigations, I found that there is a specific call of bind from React that made the polyfill crash (link):
var HTMLDOMPropertyConfig = {
  isCustomAttribute: RegExp.prototype.test.bind(
    /^(data|aria)-[a-z_][a-z\d_.\-]*$/
  )
  // [...]
};
RegExp.prototype.test is a native function and has no prototype, so the line fNOP.prototype = this.prototype; was setting fNOP's prototype to undefined, which made the test this instanceof fNOP throw the error: the right operand of instanceof must have an object prototype.
After having discussed with @rauschma on Twitter, he told me that this while fNOP's related code is certainly here to deal with using a bound function as a constructor, which makes sense.
The solution

I think that just testing that the function to bind has actually a prototype before setting it as fNOP.prototype would solve the issue. So the fixed version would be:
if (!Function.prototype.bind) {
  Function.prototype.bind = function(oThis) {
    if (typeof this !== 'function') {
      // closest thing possible to the ECMAScript 5
      // internal IsCallable function
      throw new TypeError('Function.prototype.bind - what is trying to be bound is not callable');
    }

    var aArgs   = Array.prototype.slice.call(arguments, 1),
        fToBind = this,
        fNOP    = function() {},
        fBound  = function() {
          return fToBind.apply(this instanceof fNOP && oThis
                 ? this
                 : oThis,
                 aArgs.concat(Array.prototype.slice.call(arguments)));
        };

    // test this.prototype in case of native functions binding:
    if (this.prototype)
      fNOP.prototype = this.prototype;
    fBound.prototype = new fNOP();

    return fBound;
  };
}
My problem is that:

I do not know who is the original author
I do not know if there is an existing tests suit for polyfills
I do not know where to submit that fix if is the good way to solve my problem

A quick Github search shows that this polyfill is used in many places, and if it fails with binding native functions, it looks a bit dangerous to let that out.