Question

I’m testing one of my functions, and I want to test whether a specific function is called with the right argument from that code.

For that reason, I overwrite the original function like this:

var oldSort = sort;
sort = function(array) {
    this.arrayToSort = array;
}

Then I execute it and check that the property sort.arrayToSort is set to the value I passed in and reassign the original function:

sort(myArray);
deepEqual(myArray, sort.arrayToSort); 
sort = oldSort;

However, I can’t access sort.arrayToSort like that. How can I set a property of the function to make that possible? Right now, I’m declaring a variable above the sort function and have it set that, but I’d rather have it as a property of the function to keep its scope small. Is that possible?

Answer 1

Sounds like you want arguments.callee, which refers to the function itself, rather than the object it was bound to.

var oldSort = sort;
sort = function(array) {
    arguments.callee.arrayToSort = array;
}