mroderick/README.md

## README.md

      
    Raw
  

              README.md
            
          
    Firefox debugger bug

When using the debugger and re-using an argument name in a chain of promises, the debugger displays the second argument as undefined().
Try running the examples in Firefox and compare what the debugger displays about the argument to the second callback.

  
## index-broken.html
<!doctype html>
<html>
    <head>
        <script>
            var promises = [
                Promise.resolve('hello'),
                Promise.resolve('world')
            ];

            Promise.all(promises)
            .then(function(values){
                var morePromises = [
                    Promise.resolve('apple'),
                    Promise.resolve('pie')
                ];

                return Promise.all(morePromises);
            })
            // this `values` is displayed as `undefined()`
            .then(function(values){
                debugger;
            });
        </script>
    </head>
    <body></body>
</html>

## index-works.html
<!doctype html>
<html>
    <head>
        <script>
            var promises = [
                Promise.resolve('hello'),
                Promise.resolve('world')
            ];

            Promise.all(promises)
            .then(function(values){
                var morePromises = [
                    Promise.resolve('apple'),
                    Promise.resolve('pie')
                ];

                return Promise.all(morePromises);
            })
            // this `otherValues` displays as expected
            .then(function(otherValues){
                debugger;
            });
        </script>
    </head>
    <body></body>
</html>
	<!doctype html>
	<html>
	<head>
	<script>
	var promises = [
	Promise.resolve('hello'),
	Promise.resolve('world')
	];

	Promise.all(promises)
	.then(function(values){
	var morePromises = [
	Promise.resolve('apple'),
	Promise.resolve('pie')
	];

	return Promise.all(morePromises);
	})
	// this `values` is displayed as `undefined()`
	.then(function(values){
	debugger;
	});
	</script>
	</head>
	<body></body>
	</html>