Add erb linter (#497)

* Add eruby linter

* Update README with erb linter

* Fix example and contributions

* Remove trailing newline

* Fix for Vimscript style guide

* Eruby-linter: codereview with @w0rp
- read from stderro output_stream

* Eruby-linter: codereview => add handler for ruby

* Eruby-linter: codereview
- eruby and ruby lint use the same ruby-handler (removes
  duplicated handling logic)

* Eruby-linter: try to fix tests

README.md

@@ -70,6 +70,7 @@ name. That seems to be the fairest way to arrange this table.
 | Dockerfile | [hadolint](https://github.com/lukasmartinelli/hadolint) |
 | Elixir | [credo](https://github.com/rrrene/credo), [dogma](https://github.com/lpil/dogma) |
 | Elm | [elm-make](https://github.com/elm-lang/elm-make) |
+| Erb | [erb](https://github.com/jeremyevans/erubih) |
 | Erlang | [erlc](http://erlang.org/doc/man/erlc.html) |
 | Fortran | [gcc](https://gcc.gnu.org/) |
 | Go | [gofmt -e](https://golang.org/cmd/gofmt/), [go vet](https://golang.org/cmd/vet/), [golint](https://godoc.org/github.com/golang/lint), [gometalinter](https://github.com/alecthomas/gometalinter), [go build](https://golang.org/cmd/go/), [gosimple](https://github.com/dominikh/go-tools/tree/master/cmd/gosimple), [staticcheck](https://github.com/dominikh/go-tools/tree/master/cmd/staticcheck) |

ale_linters/eruby/erubylint.vim

@@ -0,0 +1,11 @@
+" Author: Matthias Guenther - https://wikimatze.de
+" Description: erb-lint for eruby/erb files
+
+call ale#linter#Define('eruby', {
+\   'name': 'erubylint',
+\   'executable': 'erb',
+\    'output_stream': 'stderr',
+\   'command': 'erb -P -x %t | ruby -c',
+\   'callback': 'ale#handlers#ruby#HandleSyntaxErrors',
+\})
+

ale_linters/ruby/ruby.vim

@@ -1,39 +1,10 @@
 " Author: Brandon Roehl - https://github.com/BrandonRoehl
 " Description: Ruby MRI for Ruby files
 
-function! ale_linters#ruby#ruby#Handle(buffer, lines) abort
-    " Matches patterns line the following:
-    "
-    " test.rb:3: warning: parentheses after method name is interpreted as an argument list, not a decomposed argument
-    " test.rb:8: syntax error, unexpected keyword_end, expecting end-of-input
-    let l:pattern = '\v^.+:(\d+): (warning: )?(.+)$'
-    let l:column = '\v^(\s+)\^$'
-    let l:output = []
-
-    for l:line in a:lines
-        let l:match = matchlist(l:line, l:pattern)
-        if len(l:match) == 0
-            let l:match = matchlist(l:line, l:column)
-            if len(l:match) != 0
-                let l:output[len(l:output) - 1]['col'] = len(l:match[1])
-            endif
-        else
-            call add(l:output, {
-            \   'lnum': l:match[1] + 0,
-            \   'col': 0,
-            \   'text': l:match[2] . l:match[3],
-            \   'type': empty(l:match[2]) ? 'E' : 'W',
-            \})
-        endif
-    endfor
-
-    return l:output
-endfunction
-
 call ale#linter#Define('ruby', {
 \   'name': 'ruby',
 \   'executable': 'ruby',
 \   'output_stream': 'stderr',
 \   'command': 'ruby -w -c -T1 %t',
-\   'callback': 'ale_linters#ruby#ruby#Handle',
+\   'callback': 'ale#handlers#ruby#HandleSyntaxErrors',
 \})

autoload/ale/handlers/ruby.vim

@@ -0,0 +1,37 @@
+" Author: Matthias Guenther https://wikimatze.de
+"
+" Description: This file implements handlers specific to Ruby.
+
+function! s:HandleSyntaxError(buffer, lines) abort
+    " Matches patterns line the following:
+    "
+    " test.rb:3: warning: parentheses after method name is interpreted as an argument list, not a decomposed argument
+    " test.rb:8: syntax error, unexpected keyword_end, expecting end-of-input
+    let l:pattern = '\v^.+:(\d+): (warning: )?(.+)$'
+    let l:column = '\v^(\s+)\^$'
+    let l:output = []
+
+    for l:line in a:lines
+        let l:match = matchlist(l:line, l:pattern)
+        if len(l:match) == 0
+            let l:match = matchlist(l:line, l:column)
+            if len(l:match) != 0
+                let l:output[len(l:output) - 1]['col'] = len(l:match[1])
+            endif
+        else
+            call add(l:output, {
+            \   'lnum': l:match[1] + 0,
+            \   'col': 0,
+            \   'text': l:match[2] . l:match[3],
+            \   'type': empty(l:match[2]) ? 'E' : 'W',
+            \})
+        endif
+    endfor
+
+    return l:output
+endfunction
+
+function! ale#handlers#ruby#HandleSyntaxErrors(buffer, lines) abort
+    return s:HandleSyntaxError(a:buffer, a:lines)
+endfunction
+

test/handler/test_ruby_handler.vader

@@ -24,7 +24,7 @@ Execute(The ruby handler should parse lines correctly and add the column if it c
   \     'text': 'syntax error, unexpected end-of-input, expecting keyword_end'
   \   }
   \ ],
-  \ ale_linters#ruby#ruby#Handle(255, [
+  \ ale#handlers#ruby#HandleSyntaxErrors(255, [
   \ "test.rb:6: syntax error, unexpected ';'",
   \ "        t = ;",
   \ "             ^",