Add dprint fixer (#4024)

* Add dprint fixer

* Fix windows tests

* dd dprint documentation

autoload/ale/fix/registry.vim

@@ -496,6 +496,11 @@ let s:default_registry = {
 \       'suggested_filetypes': ['lua'],
 \       'description': 'Fix Lua files with luafmt.',
 \   },
+\   'dprint': {
+\       'function': 'ale#fixers#dprint#Fix',
+\       'suggested_filetypes': ['javascript', 'typescript', 'json', 'markdown'],
+\       'description': 'Pluggable and configurable code formatting platform',
+\   },
 \   'stylua': {
 \       'function': 'ale#fixers#stylua#Fix',
 \       'suggested_filetypes': ['lua'],

autoload/ale/fixers/dprint.vim

@@ -0,0 +1,29 @@
+call ale#Set('dprint_executable', 'dprint')
+call ale#Set('dprint_executable_override', 0)
+call ale#Set('dprint_use_global', get(g:, 'ale_use_global_executables', 0))
+call ale#Set('dprint_options', '')
+call ale#Set('dprint_config', 'dprint.json')
+
+function! ale#fixers#dprint#Fix(buffer) abort
+    let l:executable = ale#path#FindExecutable(a:buffer, 'dprint', ['dprint'])
+    let l:executable_override = ale#Var(a:buffer, 'dprint_executable_override')
+
+    if !executable(l:executable) && !l:executable_override
+        return 0
+    endif
+
+    let l:options = ale#Var(a:buffer, 'dprint_options')
+    let l:config = ale#path#FindNearestFile(a:buffer, ale#Var(a:buffer, 'dprint_config'))
+
+    if !empty(l:config)
+        let l:options = l:options . ' -c ' . ale#Escape(l:config)
+    endif
+
+    let l:options = l:options . ' --stdin %s'
+
+    return {
+    \   'command': ale#Escape(l:executable)
+    \     . ' fmt '
+    \     . l:options
+    \}
+endfunction