.gitattributes

linguist-language identify/override the assumed language depending on the extension (for example by GitHub which uses the linguist library to identify languages in a repository).

For example, the following three lines make sure that *.bas, *.cls and *.frm are counted as Visual Basic for Application (VBA) source code:

*.bas linguist-language=vba
*.cls linguist-language=vba
*.frm linguist-language=vba

See also this issue in the VBAModules Github repository.