dependency spring-boot-starter-test not inherited in multiple module maven project

In my multi-module maven project, all modules have a dependency of my own "common" module, eg, module "A" have this dependency "common". And the "common" module has a spring-boot-starter-test dependency. However, when I write unit test in this "A" module, it shows that the test dependency not imported. And then I check the dependencies and found that the spring-boot-starter-test is not imported. I want to ask why? In my sense, module "A" ref "common", "common" ref spring-boot-starter-test , so the module "A" should ref spring-boot-starter-test, but the fact is not that. By the way, in spite of this spring-boot-starter-test other dependencies works well via the hirachy. Does anyone know why it is? Thank you in advance.