Before: call ale#assert#SetUpLinterTest('c', 'clangd') function! Hook1(buffer) return 'abc123' endfunction After: let g:ale_lsp_root = {} unlet! b:ale_lsp_root delfunction Hook1 call ale#assert#TearDownLinterTest() Execute(The buffer-specific variable can be a string): let b:ale_lsp_root = '/some/path' call ale#test#SetFilename('other-file.c') AssertLSPProject '/some/path' Execute(The buffer-specific variable can be a dictionary): let b:ale_lsp_root = {'clangd': '/some/path', 'golangserver': '/other/path'} call ale#test#SetFilename('other-file.c') AssertLSPProject '/some/path' Execute(The buffer-specific variable can have funcrefs): let b:ale_lsp_root = {'clangd': function('Hook1'), 'golangserver': '/path'} call ale#test#SetFilename('other-file.c') AssertLSPProject 'abc123' Execute(The global variable can be a dictionary): let g:ale_lsp_root = {'clangd': '/some/path', 'golangserver': '/other/path'} call ale#test#SetFilename('other-file.c') AssertLSPProject '/some/path' Execute(The global variable can have funcrefs): let g:ale_lsp_root = {'clangd': function('Hook1'), 'golangserver': '/path'} call ale#test#SetFilename('other-file.c') AssertLSPProject 'abc123' Execute(The buffer-specific variable overrides the global variable): let b:ale_lsp_root = {'clangd': '/some/path', 'golangserver': '/other/path'} let g:ale_lsp_root = {'clangd': '/not/this/path', 'golangserver': '/elsewhere'} call ale#test#SetFilename('other-file.c') AssertLSPProject '/some/path' Execute(The global variable is queried if the buffer-specific has no value): let b:ale_lsp_root = {'golangserver': '/other/path'} let g:ale_lsp_root = {'clangd': '/some/path', 'golangserver': '/elsewhere'} call ale#test#SetFilename('other-file.c') AssertLSPProject '/some/path' Execute(The default hook value is acceptable): call ale#test#SetFilename('other-file.c') AssertLSPProject ''