Show problems from other files for lessc

test/handler/test_lessc_handler.vader

@@ -0,0 +1,69 @@
+Before:
+  call ale#test#SetDirectory('/testplugin/test/handler')
+  call ale#test#SetFilename('testfile.less')
+
+  runtime ale_linters/less/lessc.vim
+
+After:
+  call ale#test#RestoreDirectory()
+  call ale#linter#Reset()
+
+Execute(The lessc handler should handle errors for the current file correctly):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 2,
+  \     'col': 1,
+  \     'type': 'E',
+  \     'text': 'Unrecognised input. Possibly missing something',
+  \   },
+  \ ],
+  \ ale_linters#less#lessc#Handle(bufnr(''), [
+  \   'ParseError: Unrecognised input. Possibly missing something in - on line 2, column 1:',
+  \   '1 vwewww',
+  \   '2    ',
+  \])
+
+Execute(The lessc handler should handle errors for other files in the same directory correctly):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 2,
+  \     'col': 1,
+  \     'type': 'E',
+  \     'text': 'Unrecognised input. Possibly missing something',
+  \     'filename': ale#path#Winify(g:dir . '/imported.less')
+  \   },
+  \   {
+  \     'lnum': 2,
+  \     'col': 1,
+  \     'type': 'E',
+  \     'text': 'Unrecognised input. Possibly missing something',
+  \     'filename': ale#path#Winify(g:dir . '/imported.less')
+  \   },
+  \ ],
+  \ ale_linters#less#lessc#Handle(bufnr(''), [
+  \   'ParseError: Unrecognised input. Possibly missing something in imported.less on line 2, column 1:',
+  \   '1 vwewww',
+  \   '2    ',
+  \   'ParseError: Unrecognised input. Possibly missing something in ./imported.less on line 2, column 1:',
+  \   '1 vwewww',
+  \   '2    ',
+  \])
+
+Execute(The lessc handler should handle errors for files in directories above correctly):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 2,
+  \     'col': 1,
+  \     'type': 'E',
+  \     'text': 'Unrecognised input. Possibly missing something',
+  \     'filename': ale#path#Winify(g:dir . '/../imported2.less')
+  \   },
+  \ ],
+  \ ale_linters#less#lessc#Handle(bufnr(''), [
+  \   'ParseError: Unrecognised input. Possibly missing something in ../imported2.less on line 2, column 1:',
+  \   '1 vwewww',
+  \   '2    ',
+  \])