#254 Add an option for logging the output of commands

autoload/ale/history.vim

@@ -25,17 +25,34 @@ 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
+function! s:FindHistoryItem(buffer, job_id) 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
+            return l:obj
         endif
     endfor
+
+    return {}
+endfunction
+
+" Set an exit code for a command which finished.
+function! ale#history#SetExitCode(buffer, job_id, exit_code) abort
+    let l:obj = s:FindHistoryItem(a:buffer, a:job_id)
+
+    if !empty(l:obj)
+        " If we find a match, then set the code and status.
+        let l:obj.exit_code = a:exit_code
+        let l:obj.status = 'finished'
+    endif
+endfunction
+
+" Set the output for a command which finished.
+function! ale#history#RememberOutput(buffer, job_id, output) abort
+    let l:obj = s:FindHistoryItem(a:buffer, a:job_id)
+
+    if !empty(l:obj)
+        let l:obj.output = a:output
+    endif
 endfunction