Add gopls format as a Go fixer

autoload/ale/fix/registry.vim

@@ -301,6 +301,11 @@ let s:default_registry = {
 \       'suggested_filetypes': ['gomod'],
 \       'description': 'Fix Go module files with go mod edit -fmt.',
 \   },
+\   'gopls': {
+\       'function': 'ale#fixers#gopls#Fix',
+\       'suggested_filetypes': ['go'],
+\       'description': 'Fix Go files with gopls.',
+\   },
 \   'tslint': {
 \       'function': 'ale#fixers#tslint#Fix',
 \       'suggested_filetypes': ['typescript'],

autoload/ale/fixers/gopls.vim

@@ -0,0 +1,23 @@
+" Author: Sean Enck <enckse@voidedtech.com>
+" Description: Integration of gopls format with ALE.
+
+call ale#Set('go_gopls_fix_executable', 'gopls')
+call ale#Set('go_gopls_fix_options', '')
+
+function! ale#fixers#gopls#Fix(buffer) abort
+    let l:executable = ale#Var(a:buffer, 'go_gopls_fix_executable')
+    let l:options = ale#Var(a:buffer, 'go_gopls_fix_options')
+    let l:env = ale#go#EnvString(a:buffer)
+
+    if !executable(l:executable)
+        return 0
+    endif
+
+    return {
+    \   'command': l:env . ale#Escape(l:executable)
+    \       . ' format'
+    \       . ale#Pad(l:options)
+    \       . ' -l -w %t',
+    \   'read_temporary_file': 1,
+    \}
+endfunction