你应该可以使用 __DIR__ 了.包含语句中的/data/functions.php"
(即前后两个下划线).

You should be able to use __DIR__ . "/data/functions.php" in your include statement
(that's two underscores before and after).

我在我的测试环境中做了一个快速测试，没有任何问题.

I did a quick test in my test environment and had no problems.

__DIR__ 魔术常量为您提供了正在运行的测试文件的完整路径.来自 PHP 网站:

The __DIR__ magic constant gives you the full path to the test file you are running. From the PHP website:

文件的目录.如果在包含内使用，则目录返回包含的文件.这相当于目录名(__FILE__).此目录名称没有尾部斜杠除非是根目录.

The directory of the file. If used inside an include, the directory of the included file is returned. This is equivalent to dirname(__FILE__). This directory name does not have a trailing slash unless it is the root directory.