added test for plugconfig

test/run

@@ -86,6 +86,10 @@ DOC
   make_dirs z1/ z1
   make_dirs z2/ z2
 
+
+  mkdir -p "$TEMP/configs"
+  echo "let g:plug_config_vader_test = 1" > "$TEMP/configs/yyy.vim"
+
   rm -rf "$PLUG_FIXTURES/ftplugin-msg"
   mkdir -p "$PLUG_FIXTURES/ftplugin-msg/ftplugin"
   echo "echomsg 'ftplugin-c'" > "$PLUG_FIXTURES/ftplugin-msg/ftplugin/c.vim"

test/test.vader

@@ -16,6 +16,7 @@ Execute (Initialize test environment):
   call system('cp "$PLUG_SRC" "$PLUG_TMP"')
   let patch =
   \ ['function! ResetPlug()', 'let s:loaded = {}', 'endfunction',
+  \  'function! ResetPlugConfig()', 'unlet s:config_dirs', 'endfunction',
   \  'function! CompareURI(a, b)', 'return s:compare_git_uri(a:a, a:b)', 'endfunction']
 
   if $ENV != 'vim8'

test/workflow.vader

@@ -1631,3 +1631,46 @@ Execute (#532 - Reuse plug window):
   AssertEqual 2, winnr(), 'Current window is #2 after PlugStatus (but is '.winnr().')'
   AssertEqual 2, winnr('$'), 'Three windows after PlugStatus (but got '.winnr('$').')'
   q
+
+Execute (PlugConfig shall create a new file 1/2):
+  call ResetPlug()
+  call ResetPlugConfig()
+  let g:plug_config_dir = $TEMP . '/configs'
+  let $PLUG_CONFIG_DIR = g:plug_config_dir
+  let g:plug_config_dirs = [g:plug_config_dir]
+  call plug#begin()
+  Plug '$PLUG_FIXTURES/xxx', { 'for': 'xxx' }
+  call plug#end()
+  AssertEqual 1, plug#load('xxx'), 'Loading Plugin Failed'
+  redir => out
+  PlugConfig xxx
+  AssertEqual 1, bufexists(g:plug_config_dir . '/xxx.vim'), 'Buffer not created ' . g:plug_config_dir . '/xxx.vim'
+  redir END
+
+Execute (PlugConfig shall load config if lazy):
+  AssertEqual 1, filereadable(g:plug_config_dir . '/yyy.vim')
+  call ResetPlugConfig()
+  let g:plug_config_dirs = [g:plug_config_dir]
+  call ResetPlug()
+  call plug#begin()
+  Plug '$PLUG_FIXTURES/yyy', { 'for': 'yyy' }
+  call plug#end()
+  redir => out
+  AssertEqual 0, exists('g:plug_config_vader_test'), 'Variable is set unexpected'
+  AssertEqual 1, plug#load('yyy'), 'Loading failed'
+  AssertEqual 1, exists('g:plug_config_vader_test'), 'Variable has not been set by config'
+  unlet g:plug_config_vader_test
+  redir END
+
+Execute (PlugConfig shall load config automatically):
+  AssertEqual 1, filereadable(g:plug_config_dir . '/yyy.vim')
+  call ResetPlugConfig()
+  let g:plug_config_dirs = [g:plug_config_dir]
+  call ResetPlug()
+  AssertEqual 0, exists('g:plug_config_vader_test'), 'Variable is set unexpected'
+  call plug#begin()
+  Plug '$PLUG_FIXTURES/yyy'
+  call plug#end()
+  redir => out
+  AssertEqual 1, exists('g:plug_config_vader_test'), 'Variable has not been set by config'
+  redir END