Add support for syntax_tree fixer (#4268)

This is the library that now powers prettier/plugin-ruby but is also
stands on its own: https://github.com/ruby-syntax-tree/syntax_tree

autoload/ale/fix/registry.vim

@@ -221,6 +221,11 @@ let s:default_registry = {
 \       'suggested_filetypes': ['swift'],
 \       'description': 'Apply SwiftFormat to a file.',
 \   },
+\   'syntax_tree': {
+\       'function': 'ale#fixers#syntax_tree#Fix',
+\       'suggested_filetypes': ['ruby'],
+\       'description': 'Fix ruby files with stree write',
+\   },
 \   'apple-swift-format': {
 \       'function': 'ale#fixers#appleswiftformat#Fix',
 \       'suggested_filetypes': ['swift'],

autoload/ale/fixers/syntax_tree.vim

@@ -0,0 +1,19 @@
+call ale#Set('ruby_syntax_tree_options', '')
+call ale#Set('ruby_syntax_tree_executable', 'stree')
+
+function! ale#fixers#syntax_tree#GetCommand(buffer) abort
+    let l:executable = ale#Var(a:buffer, 'ruby_syntax_tree_executable')
+    let l:options = ale#Var(a:buffer, 'ruby_syntax_tree_options')
+
+    return ale#ruby#EscapeExecutable(l:executable, 'stree')
+    \   . ' write'
+    \   . (!empty(l:options) ? ' ' . l:options : '')
+    \   . ' %t'
+endfunction
+
+function! ale#fixers#syntax_tree#Fix(buffer) abort
+    return {
+    \   'command': ale#fixers#syntax_tree#GetCommand(a:buffer),
+    \   'read_temporary_file': 1,
+    \}
+endfunction

doc/ale-ruby.txt

@@ -219,5 +219,25 @@ g:ale_ruby_standardrb_options                   *g:ale_ruby_standardrb_options*
   This variable can be changed to modify flags given to standardrb.
 
 
+===============================================================================
+syntax_tree                                              *ale-ruby-syntax_tree*
+
+g:ale_ruby_syntax_tree_executable           *g:ale_ruby_syntax_tree_executable*
+                                            *b:ale_ruby_syntax_tree_executable*
+  Type: String
+  Default: `'stree'`
+
+  Override the invoked SyntaxTree binary. Set this to `'bundle'` to invoke
+  `'bundle` `exec` stree'.
+
+
+g:ale_ruby_syntax_tree_options                 *g:ale_ruby_syntax_tree_options*
+                                               *b:ale_ruby_syntax_tree_options*
+  Type: |String|
+  Default: `''`
+
+  This variable can be changed to modify flags given to SyntaxTree.
+
+
 ===============================================================================
   vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl:

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

@@ -529,6 +529,7 @@ Notes:
   * `solargraph`
   * `sorbet`
   * `standardrb`
+  * `syntax_tree`
 * Rust
   * `cargo`!!
   * `cspell`

doc/ale.txt

@@ -3167,6 +3167,7 @@ documented in additional help files.
     solargraph............................|ale-ruby-solargraph|
     sorbet................................|ale-ruby-sorbet|
     standardrb............................|ale-ruby-standardrb|
+    syntax_tree...........................|ale-ruby-syntax_tree|
   rust....................................|ale-rust-options|
     analyzer..............................|ale-rust-analyzer|
     cargo.................................|ale-rust-cargo|

supported-tools.md

@@ -538,6 +538,7 @@ formatting.
   * [solargraph](https://solargraph.org)
   * [sorbet](https://github.com/sorbet/sorbet)
   * [standardrb](https://github.com/testdouble/standard)
+  * [syntax_tree](https://github.com/ruby-syntax-tree/syntax_tree)
 * Rust
   * [cargo](https://github.com/rust-lang/cargo) :floppy_disk: (see `:help ale-integration-rust` for configuration instructions)
   * [cspell](https://github.com/streetsidesoftware/cspell/tree/main/packages/cspell)

test/fixers/test_syntax_tree_fixer_callback.vader

@@ -0,0 +1,37 @@
+Before:
+  Save g:ale_ruby_syntax_tree_executable
+  Save g:ale_ruby_syntax_tree_options
+
+  " Use an invalid global executable, so we don't match it.
+  let g:ale_ruby_syntax_tree_executable = 'xxxinvalid'
+  let g:ale_ruby_syntax_tree_options = ''
+
+  call ale#test#SetDirectory('/testplugin/test/fixers')
+
+After:
+  Restore
+
+  call ale#test#RestoreDirectory()
+
+Execute(The syntax_tree callback should return the correct default values):
+  call ale#test#SetFilename('../test-files/ruby/dummy.rb')
+
+  AssertEqual
+  \ {
+  \   'read_temporary_file': 1,
+  \   'command': ale#Escape(g:ale_ruby_syntax_tree_executable)
+  \     . ' write %t',
+  \ },
+  \ ale#fixers#syntax_tree#Fix(bufnr(''))
+
+Execute(The syntax_tree callback should include custom options):
+  let g:ale_ruby_syntax_tree_options = '--print-width=100 --plugins=plugin/trailing_comma'
+  call ale#test#SetFilename('../test-files/ruby/with_config/dummy.rb')
+
+  AssertEqual
+  \ {
+  \   'read_temporary_file': 1,
+  \   'command': ale#Escape(g:ale_ruby_syntax_tree_executable)
+  \     . ' write --print-width=100 --plugins=plugin/trailing_comma %t',
+  \ },
+  \ ale#fixers#syntax_tree#Fix(bufnr(''))