I'm developing language support for AWK.
It appears, that when you open an external file (that resides outside of the current project root), the functions in it are reported as unused and their auto-complete doesn't work.
I assume this is because the project indices, obviously are not used for the external file.
However this is not my primary question.
At the beginning I want to add (failing) unit-tests to capture this specific situation -- opening the file in editor from outside of the project.
However, looks like all methods in `CodeInsightTestFixture myFixture`, like for example,
configure a file that is inside the test project.
When I'll be able to add a failing unit test I'll think how can I make autocompletion and usages inspection work correctly for this case.