Description
Odd title but this is a very specific issue, it seems. I've only seen this happen in Internet Explorer 9.
If you emit four or more variables with the last parameter being a function. When the function is passed through, "asyncAngularify", it also causes the third parameter (index 2) to change in to the resulting function.
E.g.
angularSocket.emit("MyEvent", dataA, dataB, dataC, someCallback);
Will get passed to socket as:
emit("MyEvent", dataA, wrappedCallback, dataC, wrappedCallback);
I believe this is a crazy issue to do with IE9s interpretation of the function. The function is defined as:
emit: function (eventName, data, callback)
Yet these parameters are never used, however, it does do:
var callback = arguments[lastIndex];
The key part here being that callback has been declared twice. Once, as parameter 3 of the arguments array (function definition) and now once as the final parameter of the arguments. So when:
callback = asyncAngularify(socket, callback);
happens, I believe it overwrites both arguments[2] and arguments[length - 1]
The fix for me so far is just to remove the variables in the function definition. Other methods would be to rename the parameters so there are no conflicting ones.