Extract stringify function.

autoload/gitgutter/async.vim

@@ -43,7 +43,7 @@ function! gitgutter#async#handle_diff_job_nvim(job_id, data, event)
   if a:event == 'stdout'
     " a:data is a list
     call s:job_finished(a:job_id)
-    call gitgutter#handle_diff(join(a:data,"\n")."\n")
+    call gitgutter#handle_diff(gitgutter#utility#stringify(a:data))
 
   elseif a:event == 'exit'
     " If the exit event is triggered without a preceding stdout event,
@@ -96,7 +96,7 @@ endfunction
 " Returns a string
 function! s:job_output(id)
   if has_key(s:jobs, a:id)
-    return join(s:jobs[a:id], "\n")."\n"
+    return gitgutter#utility#stringify(s:jobs[a:id])
   else
     return ""
   endif

autoload/gitgutter/diff.vim

@@ -310,10 +310,10 @@ function! gitgutter#diff#discard_hunks(diff, keep_header)
   endfor
 
   if a:keep_header
-    return join(modified_diff, "\n") . "\n"
+    return gitgutter#utility#stringify(modified_diff)
   else
     " Discard hunk summary too.
-    return join(modified_diff[1:], "\n") . "\n"
+    return gitgutter#utility#stringify(modified_diff[1:])
   endif
 endfunction
 
@@ -338,6 +338,6 @@ function! gitgutter#diff#adjust_hunk_summary(diff_for_hunk, staging)
     endif
     call add(adj_diff, line)
   endfor
-  return join(adj_diff, "\n") . "\n"
+  return gitgutter#utility#stringify(adj_diff)
 endfunction
 

autoload/gitgutter/utility.vim

@@ -178,3 +178,7 @@ function! gitgutter#utility#git_supports_command_line_config_override()
   let [major, minor, patch; _] = split(gitgutter#utility#git_version(), '\.')
   return major > 1 || (major == 1 && minor > 7) || (minor == 7 && patch > 1)
 endfunction
+
+function! gitgutter#utility#stringify(list)
+  return join(a:list, "\n")."\n"
+endfunction