Thanks for the patch! See 3 comments below.
diff --git a/test/lua_libs/git_util.lua b/test/lua_libs/git_util.lua
new file mode 100644
index 0000000..a75bb08
--- /dev/null
+++ b/test/lua_libs/git_util.lua
@@ -0,0 +1,51 @@
+--
+-- Lua bridge for some of the git commands.
+--
+local os = require('os')
+
+local temp_file = 'some_strange_rare_unique_file_name_for_git_util'
+
+--
+-- Exec a git command.
+-- @param params Table of parameters:
+-- * options - git options.
+-- * cmd - git command.
+-- * args - command arguments.
+-- * dir - working directory.
+-- * fout - write output to the file.
+local function exec_cmd(params)
+ local fout = params.fout
+ local shell_cmd = {'git'}
+ for _, param in pairs({'options', 'cmd', 'args'}) do
+ table.insert(shell_cmd, params[param])
+ end
+ if fout then
+ table.insert(shell_cmd, ' >' .. fout)
+ end
+ shell_cmd = table.concat(shell_cmd, ' ')
+ if params.dir then
+ shell_cmd = string.format('cd %s && %s', params.dir, shell_cmd)
+ end
+ local res = os.execute(shell_cmd)
+ assert(res == 0, 'Git cmd error: ' .. res)
+end
+
+local function log_hashes(params)
+ params.args = "--format='%h' " .. params.args
+ local local_temp_file = string.format('%s/%s', os.getenv('PWD'), temp_file)
+ params.fout = local_temp_file
+ params.cmd = 'log'
+ exec_cmd(params)
+ local lines = {}
+ for line in io.lines(local_temp_file) do
+ table.insert(lines, line)
+ end
+ os.remove(local_temp_file)
+ return lines
+end
+
+
+return {
+ exec_cmd = exec_cmd,
+ log_hashes = log_hashes
+}
