#254 Capture command exit codes in the history

autoload/ale/debugging.vim

@@ -68,7 +68,14 @@ function! s:EchoCommandHistory() abort
     endif
 
     for l:item in g:ale_buffer_info[l:buffer].history
-        echom '(' . l:item.status . ') ' . string(l:item.command)
+        let l:status_message = l:item.status
+
+        " Include the exit code in output if we have it.
+        if l:item.status ==# 'finished'
+            let l:status_message .= ' - exit code ' . l:item.exit_code
+        endif
+
+        echom '(' . l:status_message . ') ' . string(l:item.command)
     endfor
 endfunction
 

autoload/ale/engine.vim

@@ -270,7 +270,23 @@ function! ale#engine#SetResults(buffer, loclist) abort
     endif
 endfunction
 
-function! s:HandleExitNeoVim(job, data, event) abort
+function! s:SetExitCode(job, exit_code) abort
+    let l:job_id = s:GetJobID(a:job)
+
+    if !has_key(s:job_info_map, l:job_id)
+        return
+    endif
+
+    let l:buffer = s:job_info_map[l:job_id].buffer
+
+    call ale#history#SetExitCode(l:buffer, l:job_id, a:exit_code)
+endfunction
+
+function! s:HandleExitNeoVim(job, exit_code, event) abort
+    if g:ale_history_enabled
+        call s:SetExitCode(a:job, a:exit_code)
+    endif
+
     call s:HandleExit(a:job)
 endfunction
 
@@ -278,6 +294,12 @@ function! s:HandleExitVim(channel) abort
     call s:HandleExit(ch_getjob(a:channel))
 endfunction
 
+" Vim returns the exit status with one callback,
+" and the channel will close later in another callback.
+function! s:HandleExitStatusVim(job, exit_code) abort
+    call s:SetExitCode(a:job, a:exit_code)
+endfunction
+
 function! s:FixLocList(buffer, loclist) abort
     " Some errors have line numbers beyond the end of the file,
     " so we need to adjust them so they set the error at the last line
@@ -415,6 +437,12 @@ function! s:RunJob(options) abort
         \   'close_cb': function('s:HandleExitVim'),
         \}
 
+        if g:ale_history_enabled
+            " We only need to capture the exit status if we are going to
+            " save it in the history. Otherwise, we don't care.
+            let l:job_options.exit_cb = function('s:HandleExitStatusVim')
+        endif
+
         if l:output_stream ==# 'stderr'
             " Read from stderr instead of stdout.
             let l:job_options.err_cb = function('s:GatherOutputVim')

autoload/ale/history.vim

@@ -24,3 +24,18 @@ function! ale#history#Add(buffer, status, job_id, command) abort
 
     let g:ale_buffer_info[a:buffer].history = l:history
 endfunction
+
+" Set an exit code for a command which finished.
+function! ale#history#SetExitCode(buffer, job_id, exit_code) abort
+    " Search backwards to find a matching job ID. IDs might be recycled,
+    " so finding the last one should be good enough.
+    for l:obj in reverse(g:ale_buffer_info[a:buffer].history[:])
+        if l:obj.job_id == a:job_id
+            " If we find a match, then set the code and status, and stop here.
+            let l:obj.exit_code = a:exit_code
+            let l:obj.status = 'finished'
+
+            return
+        endif
+    endfor
+endfunction