Add Elvis handler for Erlang

[Elvis][1] is an Erlang style reviewer.

[1]: https://github.com/inaka/elvis

ale_linters/erlang/elvis.vim

@@ -0,0 +1,39 @@
+" Author: Dmitri Vereshchagin <dmitri.vereshchagin@gmail.com>
+" Description: Elvis linter for Erlang files
+
+call ale#Set('erlang_elvis_executable', 'elvis')
+
+function! ale_linters#erlang#elvis#Handle(buffer, lines) abort
+    let l:pattern = '\v:(\d+):[^:]+:(.+)'
+    let l:loclist = []
+
+    for l:match in ale#util#GetMatches(a:lines, l:pattern)
+        call add(l:loclist, {
+        \   'lnum': str2nr(l:match[1]),
+        \   'text': s:AbbreviateMessage(l:match[2]),
+        \   'type': 'W',
+        \})
+    endfor
+
+    return l:loclist
+endfunction
+
+function! s:AbbreviateMessage(text) abort
+    let l:pattern = '\v\c^(line \d+ is too long):.*$'
+
+    return substitute(a:text, l:pattern, '\1.', '')
+endfunction
+
+function! s:GetCommand(buffer) abort
+    let l:file = ale#Escape(expand('#' . a:buffer . ':.'))
+
+    return '%e rock --output-format=parsable ' . l:file
+endfunction
+
+call ale#linter#Define('erlang', {
+\   'name': 'elvis',
+\   'callback': 'ale_linters#erlang#elvis#Handle',
+\   'executable': {b -> ale#Var(b, 'erlang_elvis_executable')},
+\   'command': function('s:GetCommand'),
+\   'lint_file': 1,
+\})

doc/ale-erlang.txt

@@ -31,6 +31,18 @@ g:ale_erlang_dialyzer_rebar3_profile     *g:ale_erlang_dialyzer_rebar3_profile*
   This variable can be changed to specify the profile that is used to
   run dialyzer with rebar3.
 
+
+-------------------------------------------------------------------------------
+elvis                                                        *ale-erlang-elvis*
+
+g:ale_erlang_elvis_executable                   *g:ale_erlang_elvis_executable*
+                                                *b:ale_erlang_elvis_executable*
+  Type: |String|
+  Default: `'elvis'`
+
+  This variable can be changed to specify the elvis executable.
+
+
 -------------------------------------------------------------------------------
 erlc                                                          *ale-erlang-erlc*
 

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

@@ -140,6 +140,7 @@ Notes:
   * `erubis`
   * `ruumba`
 * Erlang
+  * `elvis`!!
   * `erlc`
   * `SyntaxErl`
 * Fish

doc/ale.txt

@@ -2631,6 +2631,7 @@ documented in additional help files.
     elm-make..............................|ale-elm-elm-make|
   erlang..................................|ale-erlang-options|
     dialyzer..............................|ale-erlang-dialyzer|
+    elvis.................................|ale-erlang-elvis|
     erlc..................................|ale-erlang-erlc|
     syntaxerl.............................|ale-erlang-syntaxerl|
   eruby...................................|ale-eruby-options|

supported-tools.md

@@ -149,6 +149,7 @@ formatting.
   * [erubis](https://github.com/kwatch/erubis)
   * [ruumba](https://github.com/ericqweinstein/ruumba)
 * Erlang
+  * [elvis](https://github.com/inaka/elvis) :floppy_disk:
   * [erlc](http://erlang.org/doc/man/erlc.html)
   * [SyntaxErl](https://github.com/ten0s/syntaxerl)
 * Fish

test/command_callback/test_erlang_elvis_command_callback.vader

@@ -0,0 +1,16 @@
+Before:
+  let b:file = fnamemodify(bufname(''), ':.')
+  call ale#assert#SetUpLinterTest('erlang', 'elvis')
+
+After:
+  call ale#assert#TearDownLinterTest()
+
+Execute(Default command should be correct):
+  AssertLinter 'elvis',
+  \ ale#Escape('elvis') . ' rock --output-format=parsable ' . ale#Escape(b:file)
+
+Execute(Executable should be configurable):
+  let b:ale_erlang_elvis_executable = '/path/to/elvis'
+
+  AssertLinter '/path/to/elvis',
+  \ ale#Escape('/path/to/elvis') . ' rock --output-format=parsable ' . ale#Escape(b:file)

test/handler/test_erlang_elvis_handler.vader

@@ -0,0 +1,37 @@
+Before:
+  runtime ale_linters/erlang/elvis.vim
+
+After:
+  call ale#linter#Reset()
+
+Execute(Warning messages should be handled):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 11,
+  \     'text': "Replace the 'if' expression on line 11 with a 'case' expression or function clauses.",
+  \     'type': 'W',
+  \   },
+  \   {
+  \     'lnum': 20,
+  \     'text': 'Remove the debug call to io:format/1 on line 20.',
+  \     'type': 'W',
+  \   },
+  \ ],
+  \ ale_linters#erlang#elvis#Handle(bufnr(''), [
+  \   "src/foo.erl:11:no_if_expression:Replace the 'if' expression on line 11 with a 'case' expression or function clauses.",
+  \   'src/foo.erl:20:no_debug_call:Remove the debug call to io:format/1 on line 20.',
+  \ ])
+
+Execute(Line length message shouldn't contain the line itself):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 24,
+  \     'text': 'Line 24 is too long.',
+  \     'type': 'W',
+  \   },
+  \ ],
+  \ ale_linters#erlang#elvis#Handle(bufnr(''), [
+  \   'src/foo.erl:24:line_length:Line 24 is too long:     io:format("Look ma, too long!"),.',
+  \ ])