Racket linting using raco (#2146)

ale_linters/racket/raco.vim

@@ -0,0 +1,33 @@
+" Author: aqui18 <https://github.com/aqui18>
+" Description: This file adds support for checking Racket code with raco.
+"              This is the same form of syntax-checking used by DrRacket as well. The
+"              downside is that it will only catch the first error, but none of the
+"              subsequent ones. This is due to how evaluation in Racket works.
+
+function! ale_linters#racket#raco#Handle(buffer, lines) abort
+    " Matches patterns
+    " <file>:<line>:<column> <message>
+    " eg:
+    " info.rkt:4:0: infotab-module: not a well-formed definition
+    let l:pattern = '^\(\s\)\@!\(.\+\):\(\d\+\):\(\d\+\): \(.\+\)$'
+    let l:output = []
+
+    for l:match in ale#util#GetMatches(a:lines, l:pattern)
+        call add(l:output, {
+        \   'lnum': l:match[3] + 0,
+        \   'col': l:match[4] + 0,
+        \   'type': 'E',
+        \   'text': l:match[5],
+        \})
+    endfor
+
+    return l:output
+endfunction
+
+call ale#linter#Define('racket', {
+\   'name': 'raco',
+\   'executable': 'raco',
+\   'output_stream': 'stderr',
+\   'command': 'raco expand %s',
+\   'callback': 'ale_linters#racket#raco#Handle',
+\})

test/command_callback/test_racket_raco_command_callback.vader

@@ -0,0 +1,10 @@
+Before:
+  call ale#assert#SetUpLinterTest('racket', 'raco')
+
+After:
+  call ale#assert#TearDownLinterTest()
+
+Execute(The default command and executable should be correct):
+  AssertLinter 'raco', 'raco expand %s'
+
+

test/handler/test_raco_handler.vader

@@ -0,0 +1,26 @@
+Before:
+  runtime ale_linters/racket/raco.vim
+
+After:
+  call ale#linter#Reset()
+
+Execute(The raco handler should handle errors for the current file correctly):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 4,
+  \     'col': 1,
+  \     'type': 'E',
+  \     'text': 'dfine: unbound identifier in modulemessage',
+  \   },
+  \ ],
+  \ ale_linters#racket#raco#Handle(bufnr(''), [
+  \   'foo.rkt:4:1: dfine: unbound identifier in modulemessage',
+  \   '  in: dfine',
+  \   '  context...:',
+  \   '   /usr/local/Cellar/racket/6.5/share/racket/pkgs/compiler-lib/compiler/commands/expand.rkt:34:15: loop',
+  \   '   /usr/local/Cellar/racket/6.5/share/racket/pkgs/compiler-lib/compiler/commands/expand.rkt:10:2: show-program',
+  \   '   /usr/local/Cellar/racket/6.5/share/racket/pkgs/compiler-lib/compiler/commands/expand.rkt: [running body]',
+  \   '   /usr/local/Cellar/minimal-racket/6.6/share/racket/collects/raco/raco.rkt: [running body]',
+  \   '   /usr/local/Cellar/minimal-racket/6.6/share/racket/collects/raco/main.rkt: [running body]',
+  \ ])