Isolating test folder

Is it possible to isolate the entire test folder in a way that the code completion will not show its file suggestions outside the folder?

For example,

1.When I type in a class name in /component/button.tsx, the code completion will not bring up suggestions from /test

2.But when I type in /test/button.tsx, I want it to still bring up class suggestions from all folders, including /test and /component.

Marking the test directory as `excluded` would not allow me to do the 2.