[#795] Generate error flash on Liquid syntax error

app/helpers/application_helper.rb

@@ -295,7 +295,7 @@ module ApplicationHelper
     projects.each do |project|
       s << "<label>#{ check_box_tag name, project.id, false } #{h project}</label>\n"
     end
-    s 
+    s
   end
 
   # Truncates and returns the string as a single line
@@ -487,14 +487,17 @@ module ApplicationHelper
         Rails.logger.debug msg
       end
     rescue Liquid::SyntaxError => exception
+      msg = "[Liquid Syntax Error] #{exception.message}"
       if Rails.logger && Rails.logger.debug?
-        msg = "[Liquid Syntax Error] #{exception.message}\n:\n#{exception.backtrace.join("\n")}"
-        msg << "\n\n"
-        Rails.logger.debug msg
+        log_msg = "#{msg}\n"
+        log_msg << exception.backtrace.collect{ |str| "    #{str}" }.join("\n")
+        log_msg << "\n\n"
+        Rails.logger.debug log_msg
       end
 
       # Skip Liquid if there is a syntax error
-      text = h(input_text)
+      text = content_tag(:div, msg, :class => "flash error")
+      text << h(input_text)
     end
 
     @parsed_headings = []

test/unit/lib/chili_project/liquid_test.rb

@@ -229,5 +229,13 @@ class ChiliProject::LiquidTest < ActionView::TestCase
       formatted = textilizable(text)
       assert_match  '&lt;script&gt;alert(&quot;Hello&quot;)&lt;/script&gt;', formatted
     end
+
+    should "have an error flash" do
+      text =  "{% --- something invalid %}\n"
+      formatted = textilizable(text)
+
+      assert_match /flash error/, formatted
+      assert_match '[Liquid Syntax Error]', formatted
+    end
   end
 end