Add hasOwnProperty about espruino HOT 4 CLOSED

Added now. It does return false-positives for keys in prototypes though. We'll have to wait for #278 before we can get better.

from espruino.

It does return false-positives for keys in prototypes though.

Can you clarify?

This works correctly (except for the ones that cause errors):

var o = {
  key: 1
};

// Causes an error:
// console.log(
//   "should both be true: ",
//   o.hasOwnProperty("key"), Object.prototype.hasOwnProperty.call(o, "key")
// );

console.log("should be true: ", o.hasOwnProperty("key"));

function P() {
  this.own = 1;
}
P.prototype.key = 1;

// Causes an error:
// console.log("should be true: ", P.prototype.hasOwnProperty("key"));

var p = new P();

console.log("should be false: ", p.hasOwnProperty("key"));
console.log("should be true: ", p.hasOwnProperty("own"));

results in node/v8:

should be true:  true
should be false:  false
should be true:  true

results in espruino:

should be true:  true
should be false:  false
should be true:  true

from espruino.

>({}).hasOwnProperty("clone")
=true // should be false

So it's effectively function espruinoHasOwnProperty(s) { return o.hasOwnProperty(s) || o.prototype.hasOwnProperty(s); }

It's a pain, but IMO it's better than nothing (and is documented in the function's reference).

from espruino.

Fixed now

from espruino.