Add luafmt fixer (#3289)

8 files changed, 72 insertions, 0 deletions

diff --git a/autoload/ale/fix/registry.vim b/autoload/ale/fix/registry.vim
index d71668f2..9ea5331b 100644
--- a/autoload/ale/fix/registry.vim
+++ b/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'],
diff --git a/autoload/ale/fixers/luafmt.vim b/autoload/ale/fixers/luafmt.vim
new file mode 100644
index 00000000..6cb9ef4a
--- /dev/null
+++ b/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
diff --git a/doc/ale-lua.txt b/doc/ale-lua.txt
index f1286f89..408f0c3c 100644
--- a/doc/ale-lua.txt
+++ b/doc/ale-lua.txt
@@ -31,4 +31,20 @@ g:ale_lua_luacheck_options                         *g:ale_lua_luacheck_options*
 
 
 ===============================================================================
+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:
diff --git a/doc/ale-supported-languages-and-tools.txt b/doc/ale-supported-languages-and-tools.txt
index ba96c37c..b95c3a9b 100644
--- a/doc/ale-supported-languages-and-tools.txt
+++ b/doc/ale-supported-languages-and-tools.txt
@@ -266,6 +266,7 @@ Notes:
 * Lua
   * `luac`
   * `luacheck`
+  * `luafmt`
 * Mail
   * `alex`!!
   * `languagetool`!!
diff --git a/doc/ale.txt b/doc/ale.txt
index fdd95ace..1a2938ee 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -2744,6 +2744,7 @@ 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|
diff --git a/supported-tools.md b/supported-tools.md
index cf7ee25a..4567bf10 100644
--- a/supported-tools.md
+++ b/supported-tools.md
@@ -275,6 +275,7 @@ 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:
diff --git a/test/fixers/test_luafmt_fixer_callback.vader b/test/fixers/test_luafmt_fixer_callback.vader
new file mode 100644
index 00000000..362da118
--- /dev/null
+++ b/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(''))
diff --git a/test/lua_files/testfile.lua b/test/lua_files/testfile.lua
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/test/lua_files/testfile.lua