Add luafmt fixer

autoload/ale/fix/registry.vim

@@ -375,6 +375,11 @@ let s:default_registry = {
 \       'suggested_filetypes': ['html', 'htmldjango'],
 \       'description': 'Fix HTML files with html-beautify.',
 \   },
+\   'luafmt': {
+\       'function': 'ale#fixers#luafmt#Fix',
+\       'suggested_filetypes': ['lua'],
+\       'description': 'Fix Lua files with luafmt.',
+\   },
 \   'dhall': {
 \       'function': 'ale#fixers#dhall#Fix',
 \       'suggested_filetypes': ['dhall'],

autoload/ale/fixers/luafmt.vim

@@ -0,0 +1,13 @@
+call ale#Set('lua_luafmt_executable', 'luafmt')
+call ale#Set('lua_luafmt_options', '')
+
+function! ale#fixers#luafmt#Fix(buffer) abort
+    let l:executable = ale#Var(a:buffer, 'lua_luafmt_executable')
+    let l:options = ale#Var(a:buffer, 'lua_luafmt_options')
+
+    return {
+    \   'command': ale#Escape(l:executable)
+    \       . (empty(l:options) ? '' : ' ' . l:options)
+    \       . ' --stdin',
+    \}
+endfunction

doc/ale-lua.txt

@@ -30,5 +30,21 @@ g:ale_lua_luacheck_options                         *g:ale_lua_luacheck_options*
   This variable can be set to pass additional options to luacheck.
 
 
+===============================================================================
+luafmt                                                         *ale-lua-luafmt*
+
+g:ale_lua_luafmt_executable                       *g:ale_lua_luafmt_executable*
+                                                  *b:ale_lua_luafmt_executable*
+  Type: |String|
+  Default: `'luafmt'`
+
+  This variable can be set to use a different executable for luafmt.
+
+g:ale_lua_luafmt_options                             *g:ale_lua_luafmt_options*
+                                                     *b:ale_lua_luafmt_options*
+  Type: |String|
+  Default: `''`
+
+  This variable can be set to pass additional options to the luafmt fixer.
 ===============================================================================
   vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl:

doc/ale-supported-languages-and-tools.txt

@@ -265,6 +265,7 @@ Notes:
 * Lua
   * `luac`
   * `luacheck`
+  * `luafmt`
 * Mail
   * `alex`!!
   * `languagetool`!!

doc/ale.txt

@@ -2743,6 +2743,7 @@ documented in additional help files.
   lua.....................................|ale-lua-options|
     luac..................................|ale-lua-luac|
     luacheck..............................|ale-lua-luacheck|
+    luafmt................................|ale-lua-luafmt|
   markdown................................|ale-markdown-options|
     markdownlint..........................|ale-markdown-markdownlint|
     mdl...................................|ale-markdown-mdl|

supported-tools.md

@@ -274,6 +274,7 @@ formatting.
 * Lua
   * [luac](https://www.lua.org/manual/5.1/luac.html)
   * [luacheck](https://github.com/mpeterv/luacheck)
+  * [luafmt](https://github.com/trixnz/lua-fmt)
 * Mail
   * [alex](https://github.com/wooorm/alex) :floppy_disk:
   * [languagetool](https://languagetool.org/) :floppy_disk:

test/fixers/test_luafmt_fixer_callback.vader

@@ -0,0 +1,35 @@
+Before:
+  Save g:ale_lua_luafmt_executable
+  Save g:ale_lua_luafmt_options
+
+  " Use an invalid global executable, so we don't match it.
+  let g:ale_lua_luafmt_executable = 'xxxinvalid'
+  let g:ale_lua_luafmt_options = ''
+
+  call ale#test#SetDirectory('/testplugin/test/fixers')
+
+After:
+  Restore
+
+  call ale#test#RestoreDirectory()
+
+Execute(The luafmt callback should return the correct default values):
+  call ale#test#SetFilename('../lua_files/testfile.lua')
+
+  AssertEqual
+  \ {
+  \   'command': ale#Escape('xxxinvalid') . ' --stdin',
+  \ },
+  \ ale#fixers#luafmt#Fix(bufnr(''))
+
+Execute(The luafmt callback should include custom luafmt options):
+  let g:ale_lua_luafmt_options = "--skip-children"
+  call ale#test#SetFilename('../lua_files/testfile.lua')
+
+  AssertEqual
+  \ {
+  \   'command': ale#Escape('xxxinvalid')
+  \     . ' ' . g:ale_lua_luafmt_options
+  \     . ' --stdin',
+  \ },
+  \ ale#fixers#luafmt#Fix(bufnr(''))