Fix #1822 - support go-langserver lsp.

autoload/ale/go.vim

@@ -0,0 +1,27 @@
+" Author: Horacio Sanson https://github.com/hsanson
+" Description: Functions for integrating with Go tools
+
+" Find the nearest dir listed in GOPATH and assume it the root of the go
+" project.
+function! ale#go#FindProjectRoot(buffer) abort
+    let l:sep = has('win32') ? ';' : ':'
+
+    let l:filename = ale#path#Simplify(expand('#' . a:buffer . ':p'))
+
+    for l:name in split($GOPATH, l:sep)
+      let l:path_dir = ale#path#Simplify(l:name)
+
+      " Use the directory from GOPATH if the current filename starts with it.
+      if l:filename[: len(l:path_dir) - 1] is? l:path_dir
+          return l:path_dir
+      endif
+    endfor
+
+    let l:default_go_path = ale#path#Simplify(expand('~/go'))
+
+    if isdirectory(l:default_go_path)
+      return l:default_go_path
+    endif
+
+    return ''
+endfunction