Use ... instead of optional function argument

Author: nickspoons

test/utils/async-helper.vader

@@ -10,15 +10,16 @@ Execute (set up async helper):
     call OmniSharpTestAwait(a:funcname, a:args, 1)
   endfunction
 
-  function! OmniSharpTestAwait(funcname, args, warmup = 0) abort
+  function! OmniSharpTestAwait(funcname, args, ...) abort
+    let warmup = a:0 ? a:1 : 0
     let g:OmniSharp_test_waiting = 1
     call function(a:funcname, a:args + [function('s:Callback')])()
     let starttime = reltime()
     while g:OmniSharp_test_waiting
     \ && reltime(starttime)[0] < g:OmniSharp_test_timeout
       sleep 50m
     endwhile
-    if !a:warmup
+    if !warmup
       Assert !g:OmniSharp_test_waiting, a:funcname . ' timed out'
     endif
   endfunction