Add rails_best_practices handler (resolves #655) (#751)

* Move FindRailsRoot() to more general location

* Add rails_best_practices handler (resolves #655)

* Update documentation for rails_best_practices

Also add brakeman to *ale* documentation.

* rails_best_practices: allow overriding the executable

* rails_best_practices: format help correctly

* rails_best_practices: capture tool output on Windows

2 files changed, 61 insertions, 22 deletions

diff --git a/ale_linters/ruby/brakeman.vim b/ale_linters/ruby/brakeman.vim
index 5ea531f1..269c18f0 100644
--- a/ale_linters/ruby/brakeman.vim
+++ b/ale_linters/ruby/brakeman.vim
@@ -15,7 +15,7 @@ function! ale_linters#ruby#brakeman#Handle(buffer, lines) abort
 
     for l:warning in l:result.warnings
         " Brakeman always outputs paths relative to the Rails app root
-        let l:rails_root = s:FindRailsRoot(a:buffer)
+        let l:rails_root = ale#ruby#FindRailsRoot(a:buffer)
         let l:warning_file = l:rails_root . '/' . l:warning.file
 
         if !ale#path#IsBufferPath(a:buffer, l:warning_file)
@@ -36,7 +36,7 @@ function! ale_linters#ruby#brakeman#Handle(buffer, lines) abort
 endfunction
 
 function! ale_linters#ruby#brakeman#GetCommand(buffer) abort
-    let l:rails_root = s:FindRailsRoot(a:buffer)
+    let l:rails_root = ale#ruby#FindRailsRoot(a:buffer)
 
     if l:rails_root ==? ''
         return ''
@@ -47,26 +47,6 @@ function! ale_linters#ruby#brakeman#GetCommand(buffer) abort
     \    . ' -p ' . ale#Escape(l:rails_root)
 endfunction
 
-function! s:FindRailsRoot(buffer) abort
-    " Find the nearest dir contining "app", "db", and "config", and assume it is
-    " the root of a Rails app.
-    for l:name in ['app', 'config', 'db']
-        let l:dir = fnamemodify(
-        \   ale#path#FindNearestDirectory(a:buffer, l:name),
-        \   ':h:h'
-        \)
-
-        if l:dir !=# '.'
-        \&& isdirectory(l:dir . '/app')
-        \&& isdirectory(l:dir . '/config')
-        \&& isdirectory(l:dir . '/db')
-            return l:dir
-        endif
-    endfor
-
-    return ''
-endfunction
-
 call ale#linter#Define('ruby', {
 \    'name': 'brakeman',
 \    'executable': 'brakeman',
diff --git a/ale_linters/ruby/rails_best_practices.vim b/ale_linters/ruby/rails_best_practices.vim
new file mode 100644
index 00000000..a3d9f7a2
--- /dev/null
+++ b/ale_linters/ruby/rails_best_practices.vim
@@ -0,0 +1,59 @@
+" Author: Eddie Lebow https://github.com/elebow
+" Description: rails_best_practices, a code metric tool for rails projects
+
+let g:ale_ruby_rails_best_practices_options =
+\   get(g:, 'ale_ruby_rails_best_practices_options', '')
+
+function! ale_linters#ruby#rails_best_practices#Handle(buffer, lines) abort
+    if len(a:lines) == 0
+        return []
+    endif
+
+    let l:result = json_decode(join(a:lines, ''))
+
+    let l:output = []
+
+    for l:warning in l:result
+        if !ale#path#IsBufferPath(a:buffer, l:warning.filename)
+          continue
+        endif
+
+        call add(l:output, {
+        \    'lnum': l:warning.line_number + 0,
+        \    'type': 'W',
+        \    'text': l:warning.message,
+        \})
+    endfor
+
+    return l:output
+endfunction
+
+function! ale_linters#ruby#rails_best_practices#GetCommand(buffer) abort
+    let l:executable = ale#handlers#rails_best_practices#GetExecutable(a:buffer)
+    let l:exec_args = l:executable =~? 'bundle$'
+    \   ? ' exec rails_best_practices'
+    \   : ''
+
+    let l:rails_root = ale#ruby#FindRailsRoot(a:buffer)
+
+    if l:rails_root ==? ''
+        return ''
+    endif
+
+    let l:output_file = ale#Has('win32') ? '%t ' : '/dev/stdout '
+    let l:cat_file = ale#Has('win32') ? '; type %t' : ''
+
+    return ale#Escape(l:executable) . l:exec_args
+    \    . ' --silent -f json --output-file ' . l:output_file
+    \    . ale#Var(a:buffer, 'ruby_rails_best_practices_options')
+    \    . ale#Escape(l:rails_root)
+    \    . l:cat_file
+endfunction
+
+call ale#linter#Define('ruby', {
+\    'name': 'rails_best_practices',
+\    'executable_callback': 'ale#handlers#rails_best_practices#GetExecutable',
+\    'command_callback': 'ale_linters#ruby#rails_best_practices#GetCommand',
+\    'callback': 'ale_linters#ruby#rails_best_practices#Handle',
+\    'lint_file': 1,
+\})