[RFC] Add Brakeman for Ruby on Rails (references #385) (#509)

* Add brakeman for Ruby on Rails

1 files changed, 72 insertions, 0 deletions

diff --git a/ale_linters/ruby/brakeman.vim b/ale_linters/ruby/brakeman.vim
new file mode 100644
index 00000000..3cc5b77d
--- /dev/null
+++ b/ale_linters/ruby/brakeman.vim
@@ -0,0 +1,72 @@
+" Author: Eddie Lebow https://github.com/elebow
+" Description: Brakeman, a static analyzer for Rails security
+
+let g:ale_ruby_brakeman_options =
+\   get(g:, 'ale_ruby_brakeman_options', '')
+
+function! ale_linters#ruby#brakeman#Handle(buffer, lines) abort
+    let l:result = json_decode(join(a:lines, ''))
+
+    let l:output = []
+
+    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:warning_file = l:rails_root . '/' . l:warning.file
+
+        if !ale#path#IsBufferPath(a:buffer, l:warning_file)
+          continue
+        endif
+
+        let l:text = l:warning.warning_type . ' ' . l:warning.message . ' (' . l:warning.confidence . ')'
+        let l:line = l:warning.line != v:null ? l:warning.line : 1
+
+        call add(l:output, {
+        \    'lnum': l:line,
+        \    'type': 'W',
+        \    'text': l:text,
+        \})
+    endfor
+
+    return l:output
+endfunction
+
+function! ale_linters#ruby#brakeman#GetCommand(buffer) abort
+    let l:rails_root = s:FindRailsRoot(a:buffer)
+
+    if l:rails_root ==? ''
+        return ''
+    endif
+
+    return 'brakeman -f json -q '
+    \    . ale#Var(a:buffer, 'ruby_brakeman_options')
+    \    . ' -p ' . 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',
+\    'command_callback': 'ale_linters#ruby#brakeman#GetCommand',
+\    'callback': 'ale_linters#ruby#brakeman#Handle',
+\    'lint_file': 1,
+\})