How to load resource from a relative path in a nodejs module?

In one of my NodeJS modules I need to access a file that is part of the module in an own folder (for unit tests). It tried __dirname in the calling file with a relative path to that resource file. This works when running from within vscode, but not whe executing npm test in a terminal. In that case the constructed path is one level off. How can that be? Is the __dirname value different, depending on the environment the execution starts?

via Mike Lischke