add autoflake fixer (#3779)

* first attempt

* added autoflake executable

* added Windows executable for appveyor

* delete unused files

* corrected wrong sorting

9 files changed, 113 insertions, 0 deletions

diff --git a/autoload/ale/fix/registry.vim b/autoload/ale/fix/registry.vim
index 728b6df7..45518904 100644
--- a/autoload/ale/fix/registry.vim
+++ b/autoload/ale/fix/registry.vim
@@ -17,6 +17,11 @@ let s:default_registry = {
 \       'suggested_filetypes': ['python'],
 \       'description': 'Fix import issues with autoimport.',
 \   },
+\   'autoflake': {
+\       'function': 'ale#fixers#autoflake#Fix',
+\       'suggested_filetypes': ['python'],
+\       'description': 'Fix flake issues with autoflake.',
+\   },
 \   'autopep8': {
 \       'function': 'ale#fixers#autopep8#Fix',
 \       'suggested_filetypes': ['python'],
diff --git a/autoload/ale/fixers/autoflake.vim b/autoload/ale/fixers/autoflake.vim
new file mode 100644
index 00000000..e2ad6536
--- /dev/null
+++ b/autoload/ale/fixers/autoflake.vim
@@ -0,0 +1,28 @@
+" Author: circld <circld1@gmail.com>
+" Description: Fixing files with autoflake.
+
+call ale#Set('python_autoflake_executable', 'autoflake')
+call ale#Set('python_autoflake_use_global', get(g:, 'ale_use_global_executables', 0))
+call ale#Set('python_autoflake_options', '')
+
+function! ale#fixers#autoflake#Fix(buffer) abort
+    let l:executable = ale#python#FindExecutable(
+    \   a:buffer,
+    \   'python_autoflake',
+    \   ['autoflake'],
+    \)
+
+    if !executable(l:executable)
+        return 0
+    endif
+
+    let l:options = ale#Var(a:buffer, 'python_autoflake_options')
+
+    return {
+    \   'command': ale#Escape(l:executable)
+    \       . (!empty(l:options) ? ' ' . l:options : '')
+    \       . ' --in-place '
+    \       . ' %t',
+    \   'read_temporary_file': 1,
+    \}
+endfunction
diff --git a/doc/ale-python.txt b/doc/ale-python.txt
index 58b92dc9..6deff8f2 100644
--- a/doc/ale-python.txt
+++ b/doc/ale-python.txt
@@ -44,6 +44,33 @@ The first directory containing any of the files named above will be used.
 
 
 ===============================================================================
+autoflake                                                *ale-python-autoflake*
+
+g:ale_python_autoflake_executable           *g:ale_python_autoflake_executable*
+                                            *b:ale_python_autoflake_executable*
+  Type: |String|
+  Default: `'autoflake'`
+
+  See |ale-integrations-local-executables|
+
+
+g:ale_python_autoflake_options                 *g:ale_python_autoflake_options*
+                                               *b:ale_python_autoflake_options*
+  Type: |String|
+  Default: `''`
+
+  This variable can be set to pass extra options to autoflake.
+
+
+g:ale_python_autoflake_use_global           *g:ale_python_autoflake_use_global*
+                                            *b:ale_python_autoflake_use_global*
+  Type: |Number|
+  Default: `get(g:, 'ale_use_global_executables', 0)`
+
+  See |ale-integrations-local-executables|
+
+
+===============================================================================
 autoimport                                              *ale-python-autoimport*
 
 g:ale_python_autoimport_executable             *g:ale_python_autoimport_executable*
@@ -69,6 +96,7 @@ g:ale_python_autoimport_use_global             *g:ale_python_autoimport_use_glob
 
   See |ale-integrations-local-executables|
 
+
 ===============================================================================
 autopep8                                                  *ale-python-autopep8*
 
diff --git a/doc/ale-supported-languages-and-tools.txt b/doc/ale-supported-languages-and-tools.txt
index 283caf06..d71d9354 100644
--- a/doc/ale-supported-languages-and-tools.txt
+++ b/doc/ale-supported-languages-and-tools.txt
@@ -399,6 +399,7 @@ Notes:
   * `purescript-language-server`
   * `purty`
 * Python
+  * `autoflake`!!
   * `autoimport`
   * `autopep8`
   * `bandit`
diff --git a/doc/ale.txt b/doc/ale.txt
index f2800ff0..1ec22c18 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -2933,6 +2933,7 @@ documented in additional help files.
   pyrex (cython)..........................|ale-pyrex-options|
     cython................................|ale-pyrex-cython|
   python..................................|ale-python-options|
+    autoflake.............................|ale-python-autoflake|
     autoimport............................|ale-python-autoimport|
     autopep8..............................|ale-python-autopep8|
     bandit................................|ale-python-bandit|
diff --git a/supported-tools.md b/supported-tools.md
index d4e55f86..e823232b 100644
--- a/supported-tools.md
+++ b/supported-tools.md
@@ -408,6 +408,7 @@ formatting.
   * [purescript-language-server](https://github.com/nwolverson/purescript-language-server)
   * [purty](https://gitlab.com/joneshf/purty)
 * Python
+  * [autoflake](https://github.com/myint/autoflake)
   * [autoimport](https://lyz-code.github.io/autoimport/)
   * [autopep8](https://github.com/hhatto/autopep8)
   * [bandit](https://github.com/PyCQA/bandit) :warning:
diff --git a/test/fixers/test_autoflake_fixer_callback.vader b/test/fixers/test_autoflake_fixer_callback.vader
new file mode 100644
index 00000000..91fc62b5
--- /dev/null
+++ b/test/fixers/test_autoflake_fixer_callback.vader
@@ -0,0 +1,49 @@
+Before:
+  Save g:ale_python_autoflake_executable
+  Save g:ale_python_autoflake_options
+
+  " Use an invalid global executable, so we don't match it.
+  let g:ale_python_autoflake_executable = 'xxxinvalid'
+  let g:ale_python_autoflake_options = ''
+
+  call ale#test#SetDirectory('/testplugin/test/fixers')
+  let g:dir = getcwd()
+
+  let b:bin_dir = has('win32') ? 'Scripts' : 'bin'
+
+After:
+  Restore
+
+  unlet! b:bin_dir
+
+  call ale#test#RestoreDirectory()
+
+Execute(The autoflake callback should return the correct default values):
+  AssertEqual
+  \ 0,
+  \ ale#fixers#autoflake#Fix(bufnr(''))
+
+  silent execute 'file ' . fnameescape(g:dir . '/../test-files/python/with_virtualenv/subdir/foo/bar.py')
+  AssertEqual
+  \ {
+  \   'command': ale#Escape(ale#path#Simplify(g:dir . '/../test-files/python/with_virtualenv/env/' . b:bin_dir . '/autoflake'))
+  \     . ' --in-place '
+  \     . ' %t',
+  \   'read_temporary_file': 1,
+  \ },
+  \ ale#fixers#autoflake#Fix(bufnr(''))
+
+
+Execute(The autoflake callback should include options):
+  let g:ale_python_autoflake_options = '--some-option'
+
+  silent execute 'file ' . fnameescape(g:dir . '/../test-files/python/with_virtualenv/subdir/foo/bar.py')
+  AssertEqual
+  \ {
+  \   'command': ale#Escape(ale#path#Simplify(g:dir . '/../test-files/python/with_virtualenv/env/' . b:bin_dir . '/autoflake'))
+  \     . ' --some-option'
+  \     . ' --in-place '
+  \     . ' %t',
+  \   'read_temporary_file': 1,
+  \ },
+  \ ale#fixers#autoflake#Fix(bufnr(''))
diff --git a/test/test-files/python/with_virtualenv/env/Scripts/autoflake.exe b/test/test-files/python/with_virtualenv/env/Scripts/autoflake.exe
new file mode 100755
index 00000000..e69de29b
--- /dev/null
+++ b/test/test-files/python/with_virtualenv/env/Scripts/autoflake.exe
diff --git a/test/test-files/python/with_virtualenv/env/bin/autoflake b/test/test-files/python/with_virtualenv/env/bin/autoflake
new file mode 100755
index 00000000..e69de29b
--- /dev/null
+++ b/test/test-files/python/with_virtualenv/env/bin/autoflake