Add support for Bash and other shells. Add support for reading from stderr, and for generating the executable from functions. Both were needed to support shell linting.

README.md

@@ -19,6 +19,8 @@ follow later.
 
 | Language | Tools |
 | -------- | ----- |
+| Bash | -n flag |
+| Bourne Shell | -n flag |
 | JavaScript | [eslint](http://eslint.org/) |
 | Python | [flake8](http://flake8.pycqa.org/en/latest/) |
 

ale_linters/javascript/eslint.vim

@@ -43,6 +43,7 @@ function! ale_linters#javascript#eslint#Handle(buffer, lines)
 endfunction
 
 call ALEAddLinter('javascript', {
+\   'name': 'eslint',
 \   'executable': 'eslint',
 \   'command': 'eslint -f unix --stdin',
 \   'callback': 'ale_linters#javascript#eslint#Handle',

ale_linters/python/flake8.vim

@@ -45,6 +45,7 @@ function! ale_linters#python#flake8#Handle(buffer, lines)
 endfunction
 
 call ALEAddLinter('python', {
+\   'name': 'flake8',
 \   'executable': 'flake8',
 \   'command': 'flake8 -',
 \   'callback': 'ale_linters#python#flake8#Handle',

ale_linters/sh/shell.vim

@@ -0,0 +1,75 @@
+if exists('g:loaded_ale_linters_sh_shell')
+    finish
+endif
+
+let g:loaded_ale_linters_sh_shell = 1
+
+" This option can be changed to change the default shell when the shell
+" cannot be taken from the hashbang line.
+if !exists('g:ale_linters_sh_shell_default_shell')
+    let g:ale_linters_sh_shell_default_shell = 'bash'
+endif
+
+function! ale_linters#sh#shell#GetExecutable(buffer)
+    let shell = g:ale_linters_sh_shell_default_shell
+
+    let banglines = getbufline(a:buffer, 1)
+
+    " Take the shell executable from the hashbang, if we can.
+    if len(banglines) == 1
+        let bangmatch = matchlist(banglines[0], '^#!\([^ ]\+\)')
+
+        if len(bangmatch) > 0
+            let shell = bangmatch[1]
+        endif
+    endif
+
+    return shell
+endfunction
+
+function! ale_linters#sh#shell#GetCommand(buffer)
+    return ale_linters#sh#shell#GetExecutable(a:buffer) . ' -n'
+endfunction
+
+function! ale_linters#sh#shell#Handle(buffer, lines)
+    " Matches patterns line the following:
+    "
+    " bash: line 13: syntax error near unexpected token `d'
+    " sh: 11: Syntax error: "(" unexpected
+    let pattern = '^[^:]\+: \%(line \|\)\(\d\+\): \(.\+\)'
+    let output = []
+
+    for line in a:lines
+        let l:match = matchlist(line, pattern)
+
+        if len(l:match) == 0
+            continue
+        endif
+
+        let line = l:match[1] + 0
+        let column = 1
+        let text = l:match[2]
+        let type = 'E'
+
+        " vcol is Needed to indicate that the column is a character.
+        call add(output, {
+        \   'bufnr': a:buffer,
+        \   'lnum': line,
+        \   'vcol': 0,
+        \   'col': column,
+        \   'text': text,
+        \   'type': type,
+        \   'nr': -1,
+        \})
+    endfor
+
+    return output
+endfunction
+
+call ALEAddLinter('sh', {
+\   'name': 'shell',
+\   'output_stream': 'stderr',
+\   'executable_callback': 'ale_linters#sh#shell#GetExecutable',
+\   'command_callback': 'ale_linters#sh#shell#GetCommand',
+\   'callback': 'ale_linters#sh#shell#Handle',
+\})

plugin/ale/zmain.vim

@@ -141,20 +141,36 @@ function! s:ApplyLinter(buffer, linter)
     endif
 
     if has('nvim')
+        if a:linter.output_stream ==# 'stderr'
+            " Read from stderr instead of stdout.
+            let a:linter.job = jobstart(command, {
+            \   'on_stderr': 's:GatherOutputNeoVim',
+            \   'on_exit': 's:HandleExitNeoVim',
+            \})
+        else
             let a:linter.job = jobstart(command, {
             \   'on_stdout': 's:GatherOutputNeoVim',
             \   'on_exit': 's:HandleExitNeoVim',
             \})
+        endif
     else
-        " Vim 8 will read the stdin from the file's buffer.
-        let a:linter.job = job_start(command, {
+        let job_options = {
         \   'out_mode': 'nl',
         \   'err_mode': 'nl',
-        \   'out_cb': function('s:GatherOutputVim'),
         \   'close_cb': function('s:HandleExitVim'),
         \   'in_io': 'buffer',
         \   'in_buf': a:buffer,
-        \})
+        \}
+
+        if a:linter.output_stream ==# 'stderr'
+            " Read from stderr instead of stdout.
+            let job_options.err_cb = function('s:GatherOutputVim')
+        else
+            let job_options.out_cb = function('s:GatherOutputVim')
+        endif
+
+        " Vim 8 will read the stdin from the file's buffer.
+        let a:linter.job = job_start(l:command, l:job_options)
 
         call ch_close_in(job_getchannel(a:linter.job))
     endif
@@ -182,6 +198,18 @@ function! s:TimerHandler(...)
     let g:ale_buffer_should_reset_map[buffer] = 1
 
     for linter in linters
+        " Check if a given linter has a program which can be executed.
+        if has_key(linter, 'executable_callback')
+            let l:executable = s:GetFunction(linter.executable_callback)(buffer)
+        else
+            let l:executable = linter.executable
+        endif
+
+        if !executable(l:executable)
+            " The linter's program cannot be executed, so skip it.
+            continue
+        endif
+
         call s:ApplyLinter(buffer, linter)
     endfor
 endfunction
@@ -197,16 +225,20 @@ function s:BufferCleanup(buffer)
 endfunction
 
 function! ALEAddLinter(filetype, linter)
-    " Check if the linter program is executable before adding it.
-    if !executable(a:linter.executable)
-        return
-    endif
-
     if !has_key(s:linters, a:filetype)
         let s:linters[a:filetype] = []
     endif
 
-    let new_linter = {'callback': a:linter.callback}
+    let new_linter = {
+    \   'name': a:linter.name,
+    \   'callback': a:linter.callback,
+    \}
+
+    if has_key(a:linter, 'executable_callback')
+        let new_linter.executable_callback = a:linter.executable_callback
+    else
+        let new_linter.executable = a:linter.executable
+    endif
 
     if has_key(a:linter, 'command_callback')
         let new_linter.command_callback = a:linter.command_callback
@@ -214,6 +246,14 @@ function! ALEAddLinter(filetype, linter)
         let new_linter.command = a:linter.command
     endif
 
+    if has_key(a:linter, 'output_stream')
+        let new_linter.output_stream = a:linter.output_stream
+    else
+        let new_linter.output_stream = 'stdout'
+    endif
+
+    " TODO: Assert the value of the output_stream to be something sensible.
+
     call add(s:linters[a:filetype], new_linter)
 endfunction