Agreed. The following idea came up on Slack some time ago:
You type (foo, bar, <tab> or (foo, bar)<tab> and get a list of methods that take foo, bar, … as arguments. If you select one of those we insert the method before the parenthesis and return the cursor to where it was, so you’d end up with somemethod(foo, bar, | or somemethod(foo, bar)|.
That should be fairly easy to implement, but there still is the issue that the list of methods you are going to get will be big – simply because duck typing is so prevalent in Julia.