From 0beb4a4793a05557cfb0a32f94c41616606efced Mon Sep 17 00:00:00 2001
From: Tristan Hume <tristan.hume@jadedpixel.com>
Date: Mon, 19 Aug 2013 15:45:05 -0400
Subject: [PATCH] Add handy context to strict parser error messages.

---
 lib/liquid/tag.rb                  | 12 ++++++++++--
 lib/liquid/variable.rb             |  3 +++
 test/liquid/error_handling_test.rb | 14 +++++++++++++-
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/lib/liquid/tag.rb b/lib/liquid/tag.rb
index 9a354d4..ce0df63 100644
--- a/lib/liquid/tag.rb
+++ b/lib/liquid/tag.rb
@@ -35,11 +35,11 @@ module Liquid
 
     def parse_with_selected_parser(markup)
       case @options[:error_mode] || Template.error_mode
-      when :strict then strict_parse(markup)
+      when :strict then strict_parse_with_error_context(markup)
       when :lax    then lax_parse(markup)
       when :warn
         begin
-          return strict_parse(markup)
+          return strict_parse_with_error_context(markup)
         rescue SyntaxError => e
           @warnings ||= []
           @warnings << e
@@ -47,5 +47,13 @@ module Liquid
         end
       end
     end
+
+    private
+    def strict_parse_with_error_context(markup)
+      strict_parse(markup)
+    rescue SyntaxError => e
+      e.message << " in \"#{markup.strip}\"" 
+      raise e
+    end
   end # Tag
 end # Liquid
diff --git a/lib/liquid/variable.rb b/lib/liquid/variable.rb
index 20cb022..7aa2999 100644
--- a/lib/liquid/variable.rb
+++ b/lib/liquid/variable.rb
@@ -70,6 +70,9 @@ module Liquid
         @filters << [filtername, filterargs]
       end
       p.consume(:end_of_string)
+    rescue SyntaxError => e
+      e.message << " in \"{{#{markup}}}\""
+      raise e
     end
 
     def parse_filterargs(p)
diff --git a/test/liquid/error_handling_test.rb b/test/liquid/error_handling_test.rb
index 6e4889a..80902a3 100644
--- a/test/liquid/error_handling_test.rb
+++ b/test/liquid/error_handling_test.rb
@@ -79,11 +79,23 @@ class ErrorHandlingTest < Test::Unit::TestCase
     end
   end
 
+  def test_strict_error_messages
+    err = assert_raise(SyntaxError) do
+      Liquid::Template.parse(' {% if 1 =! 2 %}ok{% endif %} ', :error_mode => :strict)
+    end
+    assert_equal 'Unexpected character = in "1 =! 2"', err.message
+
+    err = assert_raise(SyntaxError) do
+      Liquid::Template.parse('{{%%%}}', :error_mode => :strict)
+    end
+    assert_equal 'Unexpected character % in "{{%%%}}"', err.message
+  end
+
   def test_warnings
     template = Liquid::Template.parse('{% if ~~~ %}derp{% else %}wat{% endif %}', :error_mode => :warn)
     assert_equal 'wat', template.render
     assert_equal 1, template.errors.size
-    assert_equal 'Unexpected character ~.', template.errors.first.message
+    assert_equal 'Unexpected character ~ in "~~~"', template.errors.first.message
   end
 
   # Liquid should not catch Exceptions that are not subclasses of StandardError, like Interrupt and NoMemoryError