refactor(git): improve cross-platform compatibility and simplify command execution

- use OS-specific path separator for .git directory checks
- redirect stderr appropriately for Windows and Unix in git commands
- replace io.popen with vim.fn.system for git command execution
- pass commit message via stdin instead of temporary file
- handle head equivalent for get_contributors on Windows using PowerShell
- improve error handling for git command execution

Author: jinzhongjia

lua/codecompanion/_extensions/gitcommit/git.lua

@@ -77,7 +77,8 @@ end
 function Git.is_repository()
   -- First check for .git directory in current and parent directories
   local function check_git_dir(path)
-    local git_path = path .. "/.git"
+    local sep = package.config:sub(1, 1)
+    local git_path = path .. sep .. ".git"
     local stat = vim.uv.fs_stat(git_path)
     return stat ~= nil
   end
@@ -99,7 +100,8 @@ function Git.is_repository()
   end
 
   -- Fallback to git command if filesystem check fails
-  local cmd = "git rev-parse --is-inside-work-tree"
+  local redirect = (vim.loop.os_uname().sysname == "Windows_NT") and " 2>nul" or " 2>/dev/null"
+  local cmd = "git rev-parse --is-inside-work-tree" .. redirect
   local result = vim.fn.system(cmd)
   return vim.v.shell_error == 0 and vim.trim(result) == "true"
 end
@@ -224,31 +226,17 @@ function Git.commit_changes(message)
     return false
   end
 
-  -- Create temporary file for commit message
-  local temp_file = vim.fn.tempname()
-  local file = io.open(temp_file, "w")
-  if not file then
-    vim.notify("Failed to create temporary file for commit message", vim.log.levels.ERROR)
-    return false
-  end
-
-  file:write(message)
-  file:close()
-
-  -- Execute appropriate git commit command
+  -- 直接通过 stdin 传递 commit message，无需临时文件
   local cmd
   if Git.is_amending() then
-    cmd = string.format("git commit --amend -F %s", vim.fn.shellescape(temp_file))
+    cmd = "git commit --amend -F -"
   else
-    cmd = string.format("git commit -F %s", vim.fn.shellescape(temp_file))
+    cmd = "git commit -F -"
   end
 
-  local result = vim.fn.system(cmd)
+  local result = vim.fn.system(cmd, message)
   local exit_code = vim.v.shell_error
 
-  -- Clean up temporary file
-  os.remove(temp_file)
-
   if exit_code == 0 then
     local action = Git.is_amending() and "amended" or "committed"
     vim.notify(string.format("Successfully %s changes!", action), vim.log.levels.INFO)

lua/codecompanion/_extensions/gitcommit/tools/git.lua

@@ -11,15 +11,10 @@ local GitTool = {
 ---Check if we're in a git repository
 ---@return boolean
 local function is_git_repo()
-  local handle = io.popen("git rev-parse --is-inside-work-tree 2>nul")
-  if not handle then
-    return false
-  end
-
-  local result = handle:read("*a")
-  handle:close()
-
-  return result:match("true") ~= nil
+  -- 使用 Neovim 内置 vim.fn.system 代替 io.popen
+  local cmd = "git rev-parse --is-inside-work-tree"
+  local result = vim.fn.system(cmd)
+  return vim.v.shell_error == 0 and result:match("true") ~= nil
 end
 
 ---Execute git command safely
@@ -30,15 +25,13 @@ local function execute_git_command(cmd)
     return false, "Not in a git repository"
   end
 
-  local handle = io.popen(cmd .. " 2>&1")
-  if not handle then
-    return false, "Failed to execute command"
-  end
-
-  local output = handle:read("*a")
-  local success = handle:close()
+  local output = vim.fn.system(cmd)
+  local exit_code = vim.v.shell_error
 
-  return success, output or ""
+  if exit_code ~= 0 or (output and output:match("fatal: ")) then
+    return false, output
+  end
+  return true, output or ""
 end
 
 ---Get git status
@@ -243,8 +236,14 @@ end
 ---@return boolean success, string output
 function GitTool.get_contributors(count)
   count = count or 10
-  local cmd = string.format("git shortlog -sn | head -%d", count)
-  return execute_git_command(cmd)
+  local head_cmd
+  if vim.loop.os_uname().sysname == "Windows_NT" then
+    -- Use PowerShell for head equivalent
+    head_cmd = string.format("git shortlog -sn | Select-Object -First %d", count)
+  else
+    head_cmd = string.format("git shortlog -sn | head -%d", count)
+  end
+  return execute_git_command(head_cmd)
 end
 
 ---Search commits by message