Edit the test code that comes with the js language target:
var list = [1,2,3];
var ret = client.testList(list);
ret comes back as [3,3,3] when it should be echoed back as [1,2,3]
The test case never caught this because it only verified the size, and not the contents of the returned array.
I cannot find an immediate workaround, but I will try wrapping it in a dummy type like ListServiceResponse.