Added dartfmt fixer (#1683)

* Added dartfmt to Fixers
* Added dartfmt specific documentation

7 files changed, 99 insertions, 2 deletions

diff --git a/README.md b/README.md
index 8b833b40..f0b40527 100644
--- a/README.md
+++ b/README.md
@@ -111,7 +111,7 @@ formatting.
 | Cython (pyrex filetype) | [cython](http://cython.org/) |
 | D | [dmd](https://dlang.org/dmd-linux.html) |
 | Dafny | [dafny](https://rise4fun.com/Dafny) !! |
-| Dart | [dartanalyzer](https://github.com/dart-lang/sdk/tree/master/pkg/analyzer_cli) !!, [language_server](https://github.com/natebosch/dart_language_server) |
+| Dart | [dartanalyzer](https://github.com/dart-lang/sdk/tree/master/pkg/analyzer_cli) !!, [language_server](https://github.com/natebosch/dart_language_server), [dartfmt](https://github.com/dart-lang/sdk/tree/master/utils/dartfmt) |
 | Dockerfile | [hadolint](https://github.com/hadolint/hadolint) |
 | Elixir | [credo](https://github.com/rrrene/credo), [dialyxir](https://github.com/jeremyjh/dialyxir), [dogma](https://github.com/lpil/dogma), [mix](https://hexdocs.pm/mix/Mix.html) !!|
 | Elm | [elm-format](https://github.com/avh4/elm-format), [elm-make](https://github.com/elm-lang/elm-make) |
diff --git a/autoload/ale/fix/registry.vim b/autoload/ale/fix/registry.vim
index 60d7d7a8..539234c0 100644
--- a/autoload/ale/fix/registry.vim
+++ b/autoload/ale/fix/registry.vim
@@ -210,6 +210,11 @@ let s:default_registry = {
 \       'suggested_filetypes': ['qml'],
 \       'description': 'Fix QML files with qmlfmt.',
 \   },
+\   'dartfmt': {
+\       'function': 'ale#fixers#dartfmt#Fix',
+\       'suggested_filetypes': ['dart'],
+\       'description': 'Fix Dart files with dartfmt.',
+\   },
 \}
 
 " Reset the function registry to the default entries.
diff --git a/autoload/ale/fixers/dartfmt.vim b/autoload/ale/fixers/dartfmt.vim
new file mode 100644
index 00000000..0687d6d1
--- /dev/null
+++ b/autoload/ale/fixers/dartfmt.vim
@@ -0,0 +1,18 @@
+" Author: reisub0 <reisub0@gmail.com>
+" Description: Integration of dartfmt with ALE.
+
+call ale#Set('dart_dartfmt_executable', 'dartfmt')
+call ale#Set('dart_dartfmt_options', '')
+
+function! ale#fixers#dartfmt#Fix(buffer) abort
+    let l:executable = ale#Var(a:buffer, 'dart_dartfmt_executable')
+    let l:options = ale#Var(a:buffer, 'dart_dartfmt_options')
+
+    return {
+    \   'command': ale#Escape(l:executable)
+    \       . ' -w'
+    \       . (empty(l:options) ? '' : ' ' . l:options)
+    \       . ' %t',
+    \   'read_temporary_file': 1,
+    \}
+endfunction
diff --git a/doc/ale-dart.txt b/doc/ale-dart.txt
index c6faa5c2..a6d88dd8 100644
--- a/doc/ale-dart.txt
+++ b/doc/ale-dart.txt
@@ -35,4 +35,37 @@ g:ale_dart_dartanalyzer_executable         *g:ale_dart_dartanalyzer_executable*
 
 
 ===============================================================================
+dartfmt                                                      *ale-dart-dartfmt*
+
+Installation
+-------------------------------------------------------------------------------
+
+Installing Dart should probably ensure that `dartfmt` is in your `$PATH`.
+
+In case it is not, try to set the executable option to its absolute path. : >
+  " Set the executable path for dartfmt to the absolute path to it.
+  let g:ale_dart_dartfmt_executable = '/usr/lib/dart/bin/dartfmt'
+ >
+
+Options
+-------------------------------------------------------------------------------
+
+g:ale_dart_dartfmt_executable                   *g:ale_dart_dartfmt_executable*
+                                                *b:ale_dart_dartfmt_executable*
+  Type: |String|
+  Default: `''`
+
+  This variable can be set to specify an absolute path to the
+  dartfmt executable (or to specify an alternate executable).
+
+
+g:ale_dart_dartfmt_options                         *g:ale_dart_dartfmt_options*
+                                                   *b:ale_dart_dartfmt_options*
+  Type: |String|
+  Default: `''`
+
+  This variable can be set to pass additional options to the dartfmt fixer.
+
+===============================================================================
+
   vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl:
diff --git a/doc/ale.txt b/doc/ale.txt
index cba164f9..f8b3141c 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -59,6 +59,7 @@ CONTENTS                                                         *ale-contents*
       nvcc................................|ale-cuda-nvcc|
     dart..................................|ale-dart-options|
       dartanalyzer........................|ale-dart-dartanalyzer|
+      dartfmt.............................|ale-dart-dartfmt|
     dockerfile............................|ale-dockerfile-options|
       hadolint............................|ale-dockerfile-hadolint|
     elixir................................|ale-elixir-options|
@@ -342,7 +343,7 @@ Notes:
 * Cython (pyrex filetype): `cython`
 * D: `dmd`
 * Dafny: `dafny`!!
-* Dart: `dartanalyzer`!!, `language_server`
+* Dart: `dartanalyzer`!!, `language_server`, dartfmt!!
 * Dockerfile: `hadolint`
 * Elixir: `credo`, `dialyxir`, `dogma`, `mix`!!
 * Elm: `elm-format, elm-make`
diff --git a/test/dart_files/testfile.dart b/test/dart_files/testfile.dart
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/test/dart_files/testfile.dart
diff --git a/test/fixers/test_dartfmt_fixer_callback.vader b/test/fixers/test_dartfmt_fixer_callback.vader
new file mode 100644
index 00000000..79c40eff
--- /dev/null
+++ b/test/fixers/test_dartfmt_fixer_callback.vader
@@ -0,0 +1,40 @@
+Before:
+  Save g:ale_dart_dartfmt_executable
+  Save g:ale_dart_dartfmt_options
+
+  " Use an invalid global executable, so we don't match it.
+  let g:ale_dart_dartfmt_executable = 'xxxinvalid'
+  let g:ale_dart_dartfmt_options = ''
+
+  call ale#test#SetDirectory('/testplugin/test/fixers')
+
+After:
+  Restore
+
+  call ale#test#RestoreDirectory()
+
+Execute(The dartfmt callback should return the correct default values):
+  call ale#test#SetFilename('../dart_files/testfile.dart')
+
+  AssertEqual
+  \ {
+  \   'read_temporary_file': 1,
+  \   'command': ale#Escape('xxxinvalid')
+  \     . ' -w'
+  \     . ' %t',
+  \ },
+  \ ale#fixers#dartfmt#Fix(bufnr(''))
+
+Execute(The dartfmt callback should include custom dartfmt options):
+  let g:ale_dart_dartfmt_options = "-l 80"
+  call ale#test#SetFilename('../dart_files/testfile.dart')
+
+  AssertEqual
+  \ {
+  \   'read_temporary_file': 1,
+  \   'command': ale#Escape('xxxinvalid')
+  \     . ' -w'
+  \     . ' ' . g:ale_dart_dartfmt_options
+  \     . ' %t',
+  \ },
+  \ ale#fixers#dartfmt#Fix(bufnr(''))