Variable named 'yield' causes problems in shrinksafe

[Bryan Forbes]

Running this code through shrinksafe:

{
	compute: function(yield, other){
		return yield + other;
	}
}

changes it to this:

compute:
function(_1,_2){
return _2+_2;
};

Changing "yield" to something like "yield2" or removing the second argument fixes the problem.

[dante]

I made a quick test to see myself:

var result = 0;
(function(){

	var fn = function(yield, foo){
		return yield + foo;
	}
	
	result = fn(1, 2);

})();

outputs

var result=0;
(function(){
var fn=function(fn,_1){
return _1+_1;
};
result=fn(1,2);
})();

notice the 'fn' being "yielded" to the previous var? weeeird.

should I check in a failing unit test? (or just return; from the test, but have it in place?)

[Adam Peller]

Yield is a language feature of JavaScript? 1.7, which Rhino implements

​https://developer.mozilla.org/en/New_in_JavaScript_1.7

but is not a reserved word, even in ECMAScript 5

​http://bugs.ecmascript.org/ticket/413

It sounds like Rhino ought to behave if the version is set properly to something less than 1.7, but I'd suggest we avoid using terms like 'let' or 'yield' in our code.

I'm not certain this is worth addressing in 1.3.3.

[dante]

@peller - suggestions here? Could be invalid/cantfix, and document the shortcoming in Shrinksafe ... Is there a way to force rhino to use a lower version of JS at runtime/calltime? The behavior now currently is not 'safe', just need to decide if there is something we can do about it or if people should be pointed to the updated documentation. This would be a "fun" bug to track down if you were using the variable 'yield' in your code anywhere.

[Richard Backhouse]

This appears to be a bug in Rhino. When I run the test case using Rhino 1.7R2 the result is

compute: function(_1,_2){ return _1+_2; };

So it would seem that it war a parser bug that has been fixed between R1 and R2

[Adam Peller]

We never upgraded Rhino in util to 1.7R2. Should we do so and close this bug? We should add a test case while we're at it.

[bill]

(sadly) punting seemingly abandoned ticket and meta tickets to future

[Colin Snover]

Bulk update of open ticket priorities.

[bill]

I think closure will be the compressor of choice going forwards, and we don't have anyone working on shrinksafe, so closing this ticket.