diff --git a/README.md b/README.md
index c077bd126..19a4fa1a4 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,7 @@
 
 [![Build Status](https://travis-ci.org/SpaceVim/SpaceVim.svg?branch=master)](https://travis-ci.org/SpaceVim/SpaceVim)
 [![Build status](https://ci.appveyor.com/api/projects/status/eh3t5oph70abp665/branch/master?svg=true)](https://ci.appveyor.com/project/wsdjeg/spacevim/branch/master)
+[![codecov](https://codecov.io/gh/SpaceVim/SpaceVim/branch/master/graph/badge.svg)](https://codecov.io/gh/SpaceVim/SpaceVim/branch/master)
 [![Docker Build Status](https://img.shields.io/docker/build/spacevim/spacevim.svg)](https://hub.docker.com/r/spacevim/spacevim/)
 ![Version](https://img.shields.io/badge/version-1.6.0--dev-8700FF.svg)
 [![GPLv3 License](https://img.shields.io/badge/license-GPLv3-blue.svg)](LICENSE)
diff --git a/autoload/SpaceVim/api/vim/buffer.vim b/autoload/SpaceVim/api/vim/buffer.vim
index 4faa28586..e7cf0281d 100644
--- a/autoload/SpaceVim/api/vim/buffer.vim
+++ b/autoload/SpaceVim/api/vim/buffer.vim
@@ -277,7 +277,11 @@ function! s:self.displayArea() abort
 endfunction
 
 function! s:self.add_highlight(bufnr, hl, line, col, long) abort
-  
+  if exists('*nvim_buf_add_highlight')
+    call nvim_buf_add_highlight(a:bufnr, 0, a:hl, a:line, a:col, a:col + a:long)
+  else
+    call SpaceVim#logger#warn('vim#buffer.add_highlight api only support neovim', 0)
+  endif
 endfunction
 
 function! s:self.buf_get_lines(bufnr, start, end, strict_indexing) abort
@@ -295,7 +299,7 @@ function! s:self.buf_get_lines(bufnr, start, end, strict_indexing) abort
       if !bufloaded(a:bufnr)
         call bufload(a:bufnr)
       endif
-      return getbufline(a:bufnr, a:start + 1, a:end + 1)
+      return getbufline(a:bufnr, a:start + 1, a:end)
     elseif a:start >= 0 && a:end < 0 && lct + a:end >= a:start
       return self.buf_get_lines(a:bufnr, a:start, lct + a:end + 1, a:strict_indexing)
     elseif a:start <= 0 && a:end > a:start && a:end < 0 && lct + a:start >= 0
diff --git a/test/api/vim/buffer.vader b/test/api/vim/buffer.vader
index 32b6d7914..007077880 100644
--- a/test/api/vim/buffer.vader
+++ b/test/api/vim/buffer.vader
@@ -24,17 +24,12 @@ Execute ( SpaceVim api: vim#buffer buf_set_lines):
   unlet nr
   unlet buffer
 
-Execute ( SpaceVim api: vim#buffer add_highlight):
-  let buffer = SpaceVim#api#import('vim#buffer')
-  let highlit = SpaceVim#api#import('vim#highlight')
-  let nr = buffer.bufnr()
-  call buffer.add_highlight(nr,'String', 1, 1, 1)
-  AssertEqual highlit.syntax_at(1, 1), 'String'
-
 Execute ( SpaceVim api: vim#buffer buf_get_lines):
   let buffer = SpaceVim#api#import('vim#buffer')
   let nr = buffer.bufadd('')
   call setbufvar(nr, '&buftype', 'nofile')
   call setbufvar(nr, '&buflisted', 0)
   call buffer.buf_set_lines(nr, 0, 1, 0, ['line 1', 'line 2', 'line 3', 'line 4'])
-  AssertEqual buffer.buf_get_lines(nr, 1, 2, 0), ['line 2']
+  if has('patch-8.1.1610')
+    AssertEqual buffer.buf_get_lines(nr, 1, 2, 0), ['line 2']
+  endif