diff --git a/.projections.json b/.projections.json
index 851f0060d..e5f0a95c9 100644
--- a/.projections.json
+++ b/.projections.json
@@ -3,15 +3,16 @@
     "alternate": "test/api/{}.vader",
     "doc": "docs/api/{}.md"
   },
-  "autoload/SpaceVim/plugins/a.vim": {
-      "alternate": "test/plugin/a.vader",
-      "lua" : "lua/spacevim/plugin/a.lua"
+  "autoload/SpaceVim/plugins/*.vim": {
+      "alternate": "test/plugin/{}.vader",
+      "lua" : "lua/spacevim/plugin/{}.lua"
   },
-  "lua/spacevim/plugin/a.lua": {
-      "alternate": "test/lua/plugin/a.vader",
-      "vim" : "autoload/SpaceVim/plugins/a.vim"
+  "lua/spacevim/plugin/*.lua": {
+      "alternate": "test/lua/plugin/{}.vader",
+      "vim" : "autoload/SpaceVim/plugins/{}.vim"
   },
-  "test/plugin/a.vader": { "alternate": "autoload/SpaceVim/plugins/a.vim" },
+  "test/plugin/*.vader": { "alternate": "autoload/SpaceVim/plugins/{}.vim" },
+  "test/lua/plugin/*.vader": { "alternate": "lua/spacevim/plugin/{}.lua" },
   "autoload/SpaceVim/layers/lang/*.vim": { "doc": "docs/layers/lang/{}.md" },
   "test/api/*.vader": { "alternate": "autoload/SpaceVim/api/{}.vim" },
   "docs/layers/*.md": {
diff --git a/lua/spacevim/api/data/string.lua b/lua/spacevim/api/data/string.lua
index 2102d4aed..a79d94fea 100644
--- a/lua/spacevim/api/data/string.lua
+++ b/lua/spacevim/api/data/string.lua
@@ -1,20 +1,103 @@
-
-local str = {}
+--=============================================================================
+-- string.lua --- spacevim data#string api
+-- Copyright (c) 2016-2019 Wang Shidong & Contributors
+-- Author: Wang Shidong < wsdjeg@outlook.com >
+-- URL: https://spacevim.org
+-- License: GPLv3
+--=============================================================================
 
 
-function str.trim(str)
+local M = {}
+
+
+function M.trim(str)
     return str:match( "^%s*(.-)%s*$" )
 end
 
 
-function str.fill(str, length, ...)
-    if string.len(str) > length then
+function M.fill(str, length, ...)
+    local v = ''
+    if string.len(str) <= length then
+        v = str
+    else
+        local rightmost= 0
+        while string.len(string.sub(str, 0, rightmost)) < length do
+            rightmost = rightmost + 1
+        end
+
     end
+    v = string.sub(str, 0, rightmost)
+    local argvs = ...
+    local char = ' '
+    if argvs ~= nil then
+        char = argvs[1] or char
+    end
+    return v .. string.rep(char, length - string.len(v))
+end
+
+function M.strcharpart(str, start, ...)
+    
+end
+
+function M.toggle_case(str)
+    local chars = {}
+    for _, char in pairs(M.string2chars(str)) do
+        local cn = string.byte(char)
+        if cn >= 97 and cn <= 122 then
+            table.insert(chars, string.char(cn - 32))
+        elseif cn >= 65 and cn <= 90 then
+            table.insert(chars, string.char(cn + 32))
+        else
+            table.insert(chars, char)
+        end
+    end
+    return table.concat(chars, '')
+end
+
+function M.fill_left(str)
+    
+end
+
+function M.fill_middle(str, length, ...)
     
 end
 
 
-return str
+function M.trim_start(str)
+    
+end
+
+function M.trim_end(str)
+    
+end
+
+function M.string2chars(str)
+    local t = {}
+    for k in string.gmatch(str, '.') do table.insert(t, k) end
+    return t
+end
+
+function M.matchstrpos(str, need, ...)
+    
+end
+
+function M.strAllIndex(str, need, use_expr)
+    
+end
+
+function M.strQ2B(str)
+    
+end
+
+function M.strB2Q(str)
+    
+end
+
+function M.split(str, ...)
+    
+end
+
+return M
 
 -- @todo add lua string api
 
diff --git a/test/lua/data/string.vader b/test/lua/data/string.vader
new file mode 100644
index 000000000..9192d6c07
--- /dev/null
+++ b/test/lua/data/string.vader
@@ -0,0 +1,9 @@
+Execute ( SpaceVim lua api: data#string ):
+  if $SPACEVIM_LUA != 1
+    finish
+  endif
+  let cmp = SpaceVim#api#import('vim#compatible')
+  Log 'test trim()'
+  lua sp_str = require('spacevim.api').import('data.string')
+  AssertEqual cmp.luaeval("sp_str.trim(' s b ')"), 's b'
+
diff --git a/test/lua/plugin/projectmanager.vader b/test/lua/plugin/projectmanager.vader
new file mode 100644
index 000000000..e69de29bb
diff --git a/test/plugin/projectmanager.vader b/test/plugin/projectmanager.vader
new file mode 100644
index 000000000..e69de29bb