Fix Ruby 2.5 and 2.6 error detection

Apparently depending on the sub version of Ruby 2.6 and the specific syntax, the error may or may not include the comma.

Ruby 2.5 has different cases for `Unexpected end` and `unexpected end`.

Author: schneems

lib/dead_end/who_dis_syntax_error.rb

@@ -45,19 +45,20 @@ def on_parse_error(msg)
       @error = msg
       @unmatched_symbol = :unknown
 
-      if @error.match?(/unexpected end-of-input/)
+      case @error
+      when /unexpected end-of-input/
         @error_symbol = :missing_end
-      elsif @error.match?(/expecting end-of-input/)
+      when /expecting end-of-input/
         @error_symbol = :unmatched_syntax
         @unmatched_symbol = :end
-      elsif @error.match?(/unexpected `end'/) ||  # Ruby 2.7 & 3.0
-          @error.match?(/unexpected end,/) ||     # Ruby 2.6
-          @error.match?(/unexpected keyword_end/) # Ruby 2.5
-
-        @error_symbol = :unmatched_syntax
+      when /unexpected `end'/,      # Ruby 2.7 and 3.0
+           /unexpected end/,        # Ruby 2.6
+           /unexpected keyword_end/i # Ruby 2.5
 
         match = @error.match(/expecting '(?<unmatched_symbol>.*)'/)
         @unmatched_symbol = match[:unmatched_symbol].to_sym if match
+
+        @error_symbol = :unmatched_syntax
       else
         @error_symbol = :unknown
       end