mikey179/vfsstream
composer
http://packagist.p2hp.com/packages/mikey179/vfsstream
github
https://github.com/bovigo/vfsStream
phpunit 文档阐明 - 测试对文件系统进行模仿
https://phpunit.readthedocs.io/zh_CN/latest/test-doubles.html?highlight=vfsStream#test-doubles-mocking-the-filesystem
单元测试中常常应用,是虚构文件系统的流笼罩。用来在单测中 mock file system,防止对文件系统的间接操作