runtime: Add autoload/msgpack.vim helper file

test/functional/plugin/helpers.lua

@@ -0,0 +1,41 @@
+local paths = require('test.config.paths')
+
+local helpers = require('test.functional.helpers')
+local spawn, set_session, nvim_prog, merge_args =
+  helpers.spawn, helpers.set_session, helpers.nvim_prog, helpers.merge_args
+
+local additional_cmd = ''
+
+local function nvim_argv()
+  local rtp_value = ('\'%s/runtime\''):format(
+      paths.test_source_path:gsub('\'', '\'\''))
+  local nvim_argv = {nvim_prog, '-u', 'NORC', '-i', 'NONE', '-N',
+                     '--cmd', 'set shortmess+=I background=light noswapfile',
+                     '--cmd', 'let &runtimepath=' .. rtp_value,
+                     '--cmd', additional_cmd,
+                     '--embed'}
+  if helpers.prepend_argv then
+    return merge_args(helpers.prepend_argv, nvim_argv)
+  else
+    return nvim_argv
+  end
+end
+
+local session = nil
+
+local reset = function()
+  if session then
+    session:exit(0)
+  end
+  session = spawn(nvim_argv())
+  set_session(session)
+end
+
+local set_additional_cmd = function(s)
+  additional_cmd = s
+end
+
+return {
+  reset=reset,
+  set_additional_cmd=set_additional_cmd,
+}