how the ide auto-detects the test framework in the project?

I'm using Intellij 2018.2. I can't understand the logic behind the automatic detection of the test framework of the project.

I created a node/npm project and included mocha for testing. all the tests are in a "test" folder

when I right-click on the test folder Intellij show me this:

where the testing framework detected is the python testing framework.(why?)

If i right click in a test file i get this:

in this case the framework selected is mocha.

But if i install the karma test runner plugin then intellij detect python Unittest for the folder and karma for the files.

So there is a way to tell the ide that has to auto-detect only a certain frameworks?

I know i can create a run configuration but the right click is much faster especially when i have to test only some assertions.