Add an extra custom check for using endif instead of end, etc.

autoload/ale/handlers.vim

@@ -258,7 +258,8 @@ function! ale#handlers#HandleGhcFormat(buffer, lines) abort
         else
           let l:type = ''
           let l:text = l:match[3]
-        end
+        endif
+
         let l:type = l:type ==# '' ? 'E' : toupper(l:type[0])
 
         call add(l:output, {

custom-checks

@@ -67,6 +67,12 @@ check_line() {
     if [[ "$line" =~ ' '+$ ]]; then
         output_error 'Trailing whitespace'
     fi
+
+    endif_regex='^ * end?i? *$'
+
+    if [[ "$line" =~ $endif_regex ]]; then
+        output_error 'Write endif, not en, end, or endi'
+    fi
 }
 
 # Loop through all of the vim files and keep track of the file line numbers.