Prevent Range usage in templates from blowing up

Make Template.tags loop-able

.rubocop.yml

@@ -118,6 +118,8 @@ Style/ClassVars:
 Style/PerlBackrefs:
   Enabled: false
 
+Style/TrivialAccessors:
+  AllowPredicates: true
+
 Style/WordArray:
   Enabled: false
-

.travis.yml

@@ -10,6 +10,11 @@ rvm:
 
 sudo: false
 
+addons:
+  apt:
+    packages:
+    - libgmp3-dev
+
 matrix:
   allow_failures:
     - rvm: jruby-head

CONTRIBUTING.md

@@ -4,23 +4,22 @@
 
 * Bugfixes
 * Performance improvements
-* Features which are likely to be useful to the majority of Liquid users
+* Features that are likely to be useful to the majority of Liquid users
 
 ## Things we won't merge
 
-* Code which introduces considerable performance degrations
-* Code which touches performance critical parts of Liquid and comes without benchmarks
-* Features which are not important for most people (we want to keep the core Liquid code small and tidy)
-* Features which can easily be implemented on top of Liquid (for example as a custom filter or custom filesystem)
-* Code which comes without tests
-* Code which breaks existing tests
+* Code that introduces considerable performance degrations
+* Code that touches performance-critical parts of Liquid and comes without benchmarks
+* Features that are not important for most people (we want to keep the core Liquid code small and tidy)
+* Features that can easily be implemented on top of Liquid (for example as a custom filter or custom filesystem)
+* Code that does not include tests
+* Code that breaks existing tests
 
 ## Workflow
 
 * Fork the Liquid repository
 * Create a new branch in your fork
-* If it makes sense, add tests for your code and run a performance benchmark
-* Make sure all tests pass
+* If it makes sense, add tests for your code and/or run a performance benchmark
+* Make sure all tests pass (`bundle exec rake`)
 * Create a pull request
-* In the description, ping one of [@boourns](https://github.com/boourns), [@fw42](https://github.com/fw42), [@camilo](https://github.com/camilo), [@dylanahsmith](https://github.com/dylanahsmith), or [@arthurnn](https://github.com/arthurnn) and ask for a code review.
 

Gemfile

@@ -6,7 +6,7 @@ gem 'stackprof', platforms: :mri_21
 group :test do
   gem 'spy', '0.4.1'
   gem 'benchmark-ips'
-  gem 'rubocop', '>=0.32.0'
+  gem 'rubocop', '0.34.2'
 
   platform :mri do
     gem 'liquid-c', github: 'Shopify/liquid-c', ref: '2570693d8d03faa0df9160ec74348a7149436df3'

History.md

@@ -3,6 +3,12 @@
 ## 4.0.0 / not yet released / branch "master"
 
 ### Changed
+* Add to_number Drop method to allow custom drops to work with number filters (#731)
+* Add strict_variables and strict_filters options to detect undefined references (#691)
+* Improve loop performance (#681) [Florian Weingarten]
+* Rename Drop method `before_method` to `liquid_method_missing` (#661) [Thierry Joyal]
+* Add url_decode filter to invert url_encode (#645) [Larry Archer]
+* Add global_filter to apply a filter to all output (#610) [Loren Hale]
 * Add compact filter (#600) [Carson Reinke]
 * Rename deprecated "has_key?" and "has_interrupt?" methods (#593) [Florian Weingarten]
 * Include template name with line numbers in render errors (574) [Dylan Thacker-Smith]
@@ -13,8 +19,14 @@
 * Ruby 1.9 support dropped (#491) [Justin Li]
 * Liquid::Template.file_system's read_template_file method is no longer passed the context. (#441) [James Reid-Smith]
 * Remove support for `liquid_methods`
+* Liquid::Template.register_filter raises when the module overrides registered public methods as private or protected (#705) [Gaurav Chande]
 
 ### Fixed
+* Fix map filter when value is a Proc (#672) [Guillaume Malette]
+* Fix truncate filter when value is not a string (#672) [Guillaume Malette]
+* Fix behaviour of escape filter when input is nil (#665) [Tanel Jakobsoo]
+* Fix sort filter behaviour with empty array input (#652) [Marcel Cary]
+* Fix test failure under certain timezones (#631) [Dylan Thacker-Smith]
 * Fix bug in uniq filter (#595) [Florian Weingarten]
 * Fix bug when "blank" and "empty" are used as variable names (#592) [Florian Weingarten]
 * Fix condition parse order in strict mode (#569) [Justin Li]
@@ -26,7 +38,15 @@
 * Disallow variable names in the strict parser that are not valid in the lax parser (#463) [Justin Li]
 * Fix BlockBody#warnings taking exponential time to compute (#486) [Justin Li]
 
-## 3.0.3 / 2015-05-28 / branch "3-0-stable"
+## 3.0.5 / 2015-07-23 / branch "3-0-stable"
+
+* Fix test failure under certain timezones [Dylan Thacker-Smith]
+
+## 3.0.4 / 2015-07-17
+
+* Fix chained access to multi-dimensional hashes [Florian Weingarten]
+
+## 3.0.3 / 2015-05-28
 
 * Fix condition parse order in strict mode (#569) [Justin Li]
 
@@ -74,7 +94,15 @@
 * Make map filter work on enumerable drops (#233) [Florian Weingarten]
 * Improved whitespace stripping for blank blocks, related to #216 [Florian Weingarten]
 
-## 2.6.1 / 2014-01-10 / branch "2-6-stable"
+## 2.6.3 / 2015-07-23 / branch "2-6-stable"
+
+* Fix test failure under certain timezones [Dylan Thacker-Smith]
+
+## 2.6.2 / 2015-01-23
+
+* Remove duplicate hash key [Parker Moore]
+
+## 2.6.1 / 2014-01-10
 
 Security fix, cherry-picked from master (4e14a65):
 * Don't call to_sym when creating conditions for security reasons (#273) [Bouke van der Bijl]

README.md

@@ -73,3 +73,34 @@ This is useful for doing things like enabling strict mode only in the theme edit
 
 It is recommended that you enable `:strict` or `:warn` mode on new apps to stop invalid templates from being created.
 It is also recommended that you use it in the template editors of existing apps to give editors better error messages.
+
+### Undefined variables and filters
+
+By default, the renderer doesn't raise or in any other way notify you if some variables or filters are missing, i.e. not passed to the `render` method.
+You can improve this situation by passing `strict_variables: true` and/or `strict_filters: true` options to the `render` method.
+When one of these options is set to true, all errors about undefined variables and undefined filters will be stored in `errors` array of a `Liquid::Template` instance.
+Here are some examples:
+
+```ruby
+template = Liquid::Template.parse("{{x}} {{y}} {{z.a}} {{z.b}}")
+template.render({ 'x' => 1, 'z' => { 'a' => 2 } }, { strict_variables: true })
+#=> '1  2 ' # when a variable is undefined, it's rendered as nil
+template.errors
+#=> [#<Liquid::UndefinedVariable: Liquid error: undefined variable y>, #<Liquid::UndefinedVariable: Liquid error: undefined variable b>]
+```
+
+```ruby
+template = Liquid::Template.parse("{{x | filter1 | upcase}}")
+template.render({ 'x' => 'foo' }, { strict_filters: true })
+#=> '' # when at least one filter in the filter chain is undefined, a whole expression is rendered as nil
+template.errors
+#=> [#<Liquid::UndefinedFilter: Liquid error: undefined filter filter1>]
+```
+
+If you want to raise on a first exception instead of pushing all of them in `errors`, you can use `render!` method:
+
+```ruby
+template = Liquid::Template.parse("{{x}} {{y}}")
+template.render!({ 'x' => 1}, { strict_variables: true })
+#=> Liquid::UndefinedVariable: Liquid error: undefined variable y
+```

lib/liquid.rb

@@ -48,6 +48,8 @@ require 'liquid/lexer'
 require 'liquid/parser'
 require 'liquid/i18n'
 require 'liquid/drop'
+require 'liquid/tablerowloop_drop'
+require 'liquid/forloop_drop'
 require 'liquid/extensions'
 require 'liquid/errors'
 require 'liquid/interrupts'

lib/liquid/block_body.rb

@@ -76,6 +76,9 @@ module Liquid
           end
         rescue MemoryError => e
           raise e
+        rescue UndefinedVariable, UndefinedDropMethod, UndefinedFilter => e
+          context.handle_error(e, token.line_number)
+          output << nil
         rescue ::StandardError => e
           output << context.handle_error(e, token.line_number)
         end

lib/liquid/context.rb

@@ -13,7 +13,7 @@ module Liquid
   #   context['bob']  #=> nil  class Context
   class Context
     attr_reader :scopes, :errors, :registers, :environments, :resource_limits
-    attr_accessor :exception_handler, :template_name, :partial
+    attr_accessor :exception_handler, :template_name, :partial, :global_filter, :strict_variables, :strict_filters
 
     def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil)
       @environments     = [environments].flatten
@@ -21,6 +21,7 @@ module Liquid
       @registers        = registers
       @errors           = []
       @partial          = false
+      @strict_variables = false
       @resource_limits  = resource_limits || ResourceLimits.new(Template.default_resource_limits)
       squash_instance_assigns_with_environments
 
@@ -32,6 +33,7 @@ module Liquid
 
       @interrupts = []
       @filters = []
+      @global_filter = nil
     end
 
     def warnings
@@ -52,6 +54,10 @@ module Liquid
       @strainer = nil
     end
 
+    def apply_global_filter(obj)
+      global_filter.nil? ? obj : global_filter.call(obj)
+    end
+
     # are there any not handled interrupts?
     def interrupt?
       !@interrupts.empty?
@@ -200,7 +206,13 @@ module Liquid
     end
 
     def lookup_and_evaluate(obj, key)
-      if (value = obj[key]).is_a?(Proc) && obj.respond_to?(:[]=)
+      if @strict_variables && obj.respond_to?(:key?) && !obj.key?(key)
+        raise Liquid::UndefinedVariable, "undefined variable #{key}"
+      end
+
+      value = obj[key]
+
+      if value.is_a?(Proc) && obj.respond_to?(:[]=)
         obj[key] = (value.arity == 0) ? value.call : value.call(self)
       else
         value

lib/liquid/drop.rb

@@ -18,24 +18,23 @@ module Liquid
   #   tmpl = Liquid::Template.parse( ' {% for product in product.top_sales %} {{ product.name }} {%endfor%} '  )
   #   tmpl.render('product' => ProductDrop.new ) # will invoke top_sales query.
   #
-  # Your drop can either implement the methods sans any parameters or implement the before_method(name) method which is a
-  # catch all.
+  # Your drop can either implement the methods sans any parameters
+  # or implement the liquid_method_missing(name) method which is a catch all.
   class Drop
     attr_writer :context
 
-    EMPTY_STRING = ''.freeze
-
     # Catch all for the method
-    def before_method(_method)
-      nil
+    def liquid_method_missing(method)
+      return nil unless @context && @context.strict_variables
+      raise Liquid::UndefinedDropMethod, "undefined method #{method}"
     end
 
     # called by liquid to invoke a drop
     def invoke_drop(method_or_key)
-      if method_or_key && method_or_key != EMPTY_STRING && self.class.invokable?(method_or_key)
+      if self.class.invokable?(method_or_key)
         send(method_or_key)
       else
-        before_method(method_or_key)
+        liquid_method_missing(method_or_key)
       end
     end
 
@@ -63,16 +62,17 @@ module Liquid
     end
 
     def self.invokable_methods
-      unless @invokable_methods
+      @invokable_methods ||= begin
         blacklist = Liquid::Drop.public_instance_methods + [:each]
+
         if include?(Enumerable)
           blacklist += Enumerable.public_instance_methods
           blacklist -= [:sort, :count, :first, :min, :max, :include?]
         end
+
         whitelist = [:to_liquid] + (public_instance_methods - blacklist)
-        @invokable_methods = Set.new(whitelist.map(&:to_s))
+        Set.new(whitelist.map(&:to_s))
       end
-      @invokable_methods
     end
   end
 end

lib/liquid/errors.rb

@@ -56,4 +56,8 @@ module Liquid
   MemoryError = Class.new(Error)
   ZeroDivisionError = Class.new(Error)
   FloatDomainError = Class.new(Error)
+  UndefinedVariable = Class.new(Error)
+  UndefinedDropMethod = Class.new(Error)
+  UndefinedFilter = Class.new(Error)
+  MethodOverrideError = Class.new(Error)
 end

lib/liquid/extensions.rb

@@ -7,44 +7,50 @@ class String # :nodoc:
   end
 end
 
-class Array  # :nodoc:
+class Array # :nodoc:
   def to_liquid
     self
   end
 end
 
-class Hash  # :nodoc:
+class Hash # :nodoc:
   def to_liquid
     self
   end
 end
 
-class Numeric  # :nodoc:
+class Numeric # :nodoc:
   def to_liquid
     self
   end
 end
 
-class Time  # :nodoc:
+class Range # :nodoc:
   def to_liquid
     self
   end
 end
 
-class DateTime < Date  # :nodoc:
+class Time # :nodoc:
   def to_liquid
     self
   end
 end
 
-class Date  # :nodoc:
+class DateTime < Date # :nodoc:
+  def to_liquid
+    self
+  end
+end
+
+class Date # :nodoc:
   def to_liquid
     self
   end
 end
 
 class TrueClass
-  def to_liquid  # :nodoc:
+  def to_liquid # :nodoc:
     self
   end
 end

lib/liquid/file_system.rb

@@ -65,7 +65,7 @@ module Liquid
         File.join(root, @pattern % template_path)
       end
 
-      raise FileSystemError, "Illegal template path '#{File.expand_path(full_path)}'" unless File.expand_path(full_path) =~ /\A#{File.expand_path(root)}/
+      raise FileSystemError, "Illegal template path '#{File.expand_path(full_path)}'" unless File.expand_path(full_path).start_with?(File.expand_path(root))
 
       full_path
     end

lib/liquid/forloop_drop.rb

@@ -0,0 +1,42 @@
+module Liquid
+  class ForloopDrop < Drop
+    def initialize(name, length, parentloop)
+      @name = name
+      @length = length
+      @parentloop = parentloop
+      @index = 0
+    end
+
+    attr_reader :name, :length, :parentloop
+
+    def index
+      @index + 1
+    end
+
+    def index0
+      @index
+    end
+
+    def rindex
+      @length - @index
+    end
+
+    def rindex0
+      @length - @index - 1
+    end
+
+    def first
+      @index == 0
+    end
+
+    def last
+      @index == @length - 1
+    end
+
+    protected
+
+    def increment!
+      @index += 1
+    end
+  end
+end

lib/liquid/parse_context.rb

@@ -1,7 +1,7 @@
 module Liquid
   class ParseContext
-    attr_accessor :partial, :locale, :line_number
-    attr_reader :warnings, :error_mode
+    attr_accessor :locale, :line_number
+    attr_reader :partial, :warnings, :error_mode
 
     def initialize(options = {})
       @template_options = options ? options.dup : {}

lib/liquid/parser.rb

@@ -75,7 +75,7 @@ module Liquid
 
     def variable_signature
       str = consume(:id)
-      if look(:open_square)
+      while look(:open_square)
         str << consume
         str << expression
         str << consume(:close_square)

lib/liquid/standardfilters.rb

@@ -33,7 +33,7 @@ module Liquid
     end
 
     def escape(input)
-      CGI.escapeHTML(input).untaint
+      CGI.escapeHTML(input).untaint unless input.nil?
     end
     alias_method :h, :escape
 
@@ -42,7 +42,11 @@ module Liquid
     end
 
     def url_encode(input)
-      CGI.escape(input) rescue input
+      CGI.escape(input) unless input.nil?
+    end
+
+    def url_decode(input)
+      CGI.unescape(input) unless input.nil?
     end
 
     def slice(input, offset, length = nil)
@@ -59,10 +63,11 @@ module Liquid
     # Truncate a string down to x characters
     def truncate(input, length = 50, truncate_string = "...".freeze)
       return if input.nil?
+      input_str = input.to_s
       length = Utils.to_integer(length)
       l = length - truncate_string.length
       l = 0 if l < 0
-      input.length > length ? input[0...l] + truncate_string : input
+      input_str.length > length ? input_str[0...l] + truncate_string : input_str
     end
 
     def truncatewords(input, words = 15, truncate_string = "...".freeze)
@@ -116,10 +121,10 @@ module Liquid
       ary = InputIterator.new(input)
       if property.nil?
         ary.sort
+      elsif ary.empty? # The next two cases assume a non-empty array.
+        []
       elsif ary.first.respond_to?(:[]) && !ary.first[property].nil?
         ary.sort { |a, b| a[property] <=> b[property] }
-      elsif ary.first.respond_to?(property)
-        ary.sort { |a, b| a.send(property) <=> b.send(property) }
       end
     end
 
@@ -130,10 +135,10 @@ module Liquid
 
       if property.nil?
         ary.sort { |a, b| a.casecmp(b) }
+      elsif ary.empty? # The next two cases assume a non-empty array.
+        []
       elsif ary.first.respond_to?(:[]) && !ary.first[property].nil?
         ary.sort { |a, b| a[property].casecmp(b[property]) }
-      elsif ary.first.respond_to?(property)
-        ary.sort { |a, b| a.send(property).casecmp(b.send(property)) }
       end
     end
 
@@ -144,6 +149,8 @@ module Liquid
 
       if property.nil?
         ary.uniq
+      elsif ary.empty? # The next two cases assume a non-empty array.
+        []
       elsif ary.first.respond_to?(:[])
         ary.uniq{ |a| a[property] }
       end
@@ -163,7 +170,8 @@ module Liquid
         if property == "to_liquid".freeze
           e
         elsif e.respond_to?(:[])
-          e[property]
+          r = e[property]
+          r.is_a?(Proc) ? r.call : r
         end
       end
     end
@@ -175,10 +183,10 @@ module Liquid
 
       if property.nil?
         ary.compact
+      elsif ary.empty? # The next two cases assume a non-empty array.
+        []
       elsif ary.first.respond_to?(:[])
         ary.reject{ |a| a[property].nil? }
-      elsif ary.first.respond_to?(property)
-        ary.reject { |a| a.send(property).nil? }
       end
     end
 
@@ -208,6 +216,9 @@ module Liquid
     end
 
     def concat(input, array)
+      unless array.respond_to?(:to_ary)
+        raise ArgumentError.new("concat filter requires an array argument")
+      end
       InputIterator.new(input).concat(array)
     end
 
@@ -278,6 +289,12 @@ module Liquid
       array.last if array.respond_to?(:last)
     end
 
+    # absolute value
+    def abs(input)
+      result = Utils.to_number(input).abs
+      result.is_a?(BigDecimal) ? result.to_f : result
+    end
+
     # addition
     def plus(input, operand)
       apply_operation(input, operand, :+)
@@ -327,9 +344,12 @@ module Liquid
       raise Liquid::FloatDomainError, e.message
     end
 
-    def default(input, default_value = "".freeze)
-      is_blank = input.respond_to?(:empty?) ? input.empty? : !input
-      is_blank ? default_value : input
+    def default(input, default_value = ''.freeze)
+      if !input || input.respond_to?(:empty?) && input.empty?
+        default_value
+      else
+        input
+      end
     end
 
     private
@@ -359,7 +379,7 @@ module Liquid
       end
 
       def concat(args)
-        to_a.concat args
+        to_a.concat(args)
       end
 
       def reverse
@@ -374,6 +394,11 @@ module Liquid
         to_a.compact
       end
 
+      def empty?
+        @input.each { return false }
+        true
+      end
+
       def each
         @input.each do |e|
           yield(e.respond_to?(:to_liquid) ? e.to_liquid : e)

lib/liquid/strainer.rb

@@ -26,10 +26,15 @@ module Liquid
     end
 
     def self.add_filter(filter)
-      raise ArgumentError, "Expected module but got: #{f.class}" unless filter.is_a?(Module)
+      raise ArgumentError, "Expected module but got: #{filter.class}" unless filter.is_a?(Module)
       unless self.class.include?(filter)
-        send(:include, filter)
-        @filter_methods.merge(filter.public_instance_methods.map(&:to_s))
+        invokable_non_public_methods = (filter.private_instance_methods + filter.protected_instance_methods).select { |m| invokable?(m) }
+        if invokable_non_public_methods.any?
+          raise MethodOverrideError, "Filter overrides registered public methods as non public: #{invokable_non_public_methods.join(', ')}"
+        else
+          send(:include, filter)
+          @filter_methods.merge(filter.public_instance_methods.map(&:to_s))
+        end
       end
     end
 
@@ -48,11 +53,13 @@ module Liquid
     def invoke(method, *args)
       if self.class.invokable?(method)
         send(method, *args)
+      elsif @context && @context.strict_filters
+        raise Liquid::UndefinedFilter, "undefined filter #{method}"
       else
         args.first
       end
     rescue ::ArgumentError => e
-      raise Liquid::ArgumentError.new(e.message)
+      raise Liquid::ArgumentError, e.message, e.backtrace
     end
   end
 end

lib/liquid/tablerowloop_drop.rb

@@ -0,0 +1,62 @@
+module Liquid
+  class TablerowloopDrop < Drop
+    def initialize(length, cols)
+      @length = length
+      @row = 1
+      @col = 1
+      @cols = cols
+      @index = 0
+    end
+
+    attr_reader :length, :col, :row
+
+    def index
+      @index + 1
+    end
+
+    def index0
+      @index
+    end
+
+    def col0
+      @col - 1
+    end
+
+    def rindex
+      @length - @index
+    end
+
+    def rindex0
+      @length - @index - 1
+    end
+
+    def first
+      @index == 0
+    end
+
+    def last
+      @index == @length - 1
+    end
+
+    def col_first
+      @col == 1
+    end
+
+    def col_last
+      @col == @cols
+    end
+
+    protected
+
+    def increment!
+      @index += 1
+
+      if @col == @cols
+        @col = 1
+        @row += 1
+      else
+        @col += 1
+      end
+    end
+  end
+end

lib/liquid/tags/assign.rb

@@ -23,16 +23,28 @@ module Liquid
     def render(context)
       val = @from.render(context)
       context.scopes.last[@to] = val
-
-      inc = val.instance_of?(String) || val.instance_of?(Array) || val.instance_of?(Hash) ? val.length : 1
-      context.resource_limits.assign_score += inc
-
+      context.resource_limits.assign_score += assign_score_of(val)
       ''.freeze
     end
 
     def blank?
       true
     end
+
+    private
+
+    def assign_score_of(val)
+      if val.instance_of?(String)
+        val.length
+      elsif val.instance_of?(Array) || val.instance_of?(Hash)
+        sum = 1
+        # Uses #each to avoid extra allocations.
+        val.each { |child| sum += assign_score_of(child) }
+        sum
+      else
+        1
+      end
+    end
   end
 
   Template.register_tag('assign'.freeze, Assign)

lib/liquid/tags/cycle.rb

@@ -37,7 +37,7 @@ module Liquid
         iteration = context.registers[:cycle][key]
         result = context.evaluate(@variables[iteration])
         iteration += 1
-        iteration  = 0  if iteration >= @variables.size
+        iteration  = 0 if iteration >= @variables.size
         context.registers[:cycle][key] = iteration
         result
       end

lib/liquid/tags/for.rb

@@ -48,8 +48,10 @@ module Liquid
 
     def initialize(tag_name, markup, options)
       super
+      @from = @limit = nil
       parse_with_selected_parser(markup)
       @for_block = BlockBody.new
+      @else_block = nil
     end
 
     def parse(tokens)
@@ -67,69 +69,13 @@ module Liquid
     end
 
     def render(context)
-      for_offsets = context.registers[:for] ||= Hash.new(0)
-      for_stack = context.registers[:for_stack] ||= []
+      segment = collection_segment(context)
 
-      parent_loop = for_stack.last
-      for_stack.push(nil)
-
-      collection = context.evaluate(@collection_name)
-      collection = collection.to_a if collection.is_a?(Range)
-
-      from = if @from == :continue
-        for_offsets[@name].to_i
+      if segment.empty?
+        render_else(context)
       else
-        context.evaluate(@from).to_i
+        render_segment(context, segment)
       end
-
-      limit = context.evaluate(@limit)
-      to    = limit ? limit.to_i + from : nil
-
-      segment = Utils.slice_collection(collection, from, to)
-
-      return render_else(context) if segment.empty?
-
-      segment.reverse! if @reversed
-
-      result = ''
-
-      length = segment.length
-
-      # Store our progress through the collection for the continue flag
-      for_offsets[@name] = from + segment.length
-
-      context.stack do
-        segment.each_with_index do |item, index|
-          context[@variable_name] = item
-          loop_vars = {
-            'name'.freeze       => @name,
-            'length'.freeze     => length,
-            'index'.freeze      => index + 1,
-            'index0'.freeze     => index,
-            'rindex'.freeze     => length - index,
-            'rindex0'.freeze    => length - index - 1,
-            'first'.freeze      => (index == 0),
-            'last'.freeze       => (index == length - 1),
-            'parentloop'.freeze => parent_loop
-          }
-
-          context['forloop'.freeze] = loop_vars
-          for_stack[-1] = loop_vars
-
-          result << @for_block.render(context)
-
-          # Handle any interrupts if they exist.
-          if context.interrupt?
-            interrupt = context.pop_interrupt
-            break if interrupt.is_a? BreakInterrupt
-            next if interrupt.is_a? ContinueInterrupt
-          end
-        end
-      end
-
-      result
-    ensure
-      for_stack.pop
     end
 
     protected
@@ -152,7 +98,7 @@ module Liquid
     def strict_parse(markup)
       p = Parser.new(markup)
       @variable_name = p.consume(:id)
-      raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_in".freeze))  unless p.id?('in'.freeze)
+      raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_in".freeze)) unless p.id?('in'.freeze)
       collection_name = p.expression
       @name = "#{@variable_name}-#{collection_name}"
       @collection_name = Expression.parse(collection_name)
@@ -170,6 +116,63 @@ module Liquid
 
     private
 
+    def collection_segment(context)
+      offsets = context.registers[:for] ||= Hash.new(0)
+
+      from = if @from == :continue
+        offsets[@name].to_i
+      else
+        context.evaluate(@from).to_i
+      end
+
+      collection = context.evaluate(@collection_name)
+      collection = collection.to_a if collection.is_a?(Range)
+
+      limit = context.evaluate(@limit)
+      to = limit ? limit.to_i + from : nil
+
+      segment = Utils.slice_collection(collection, from, to)
+      segment.reverse! if @reversed
+
+      offsets[@name] = from + segment.length
+
+      segment
+    end
+
+    def render_segment(context, segment)
+      for_stack = context.registers[:for_stack] ||= []
+      length = segment.length
+
+      result = ''
+
+      context.stack do
+        loop_vars = Liquid::ForloopDrop.new(@name, length, for_stack[-1])
+
+        for_stack.push(loop_vars)
+
+        begin
+          context['forloop'.freeze] = loop_vars
+
+          segment.each_with_index do |item, index|
+            context[@variable_name] = item
+            result << @for_block.render(context)
+            loop_vars.send(:increment!)
+
+            # Handle any interrupts if they exist.
+            if context.interrupt?
+              interrupt = context.pop_interrupt
+              break if interrupt.is_a? BreakInterrupt
+              next if interrupt.is_a? ContinueInterrupt
+            end
+          end
+        ensure
+          for_stack.pop
+        end
+      end
+
+      result
+    end
+
     def set_attribute(key, expr)
       case key
       when 'offset'.freeze

lib/liquid/tags/raw.rb

@@ -6,9 +6,7 @@ module Liquid
     def initialize(tag_name, markup, parse_context)
       super
 
-      unless markup =~ Syntax
-        raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_unexpected_args".freeze, tag: tag_name))
-      end
+      ensure_valid_markup(tag_name, markup, parse_context)
     end
 
     def parse(tokens)
@@ -35,6 +33,14 @@ module Liquid
     def blank?
       @body.empty?
     end
+
+    protected
+
+    def ensure_valid_markup(tag_name, markup, parse_context)
+      unless markup =~ Syntax
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_unexpected_args".freeze, tag: tag_name))
+      end
+    end
   end
 
   Template.register_tag('raw'.freeze, Raw)

lib/liquid/tags/table_row.rb

@@ -28,36 +28,21 @@ module Liquid
 
       cols = context.evaluate(@attributes['cols'.freeze]).to_i
 
-      row = 1
-      col = 0
-
       result = "<tr class=\"row1\">\n"
       context.stack do
+        tablerowloop = Liquid::TablerowloopDrop.new(length, cols)
+        context['tablerowloop'.freeze] = tablerowloop
+
         collection.each_with_index do |item, index|
           context[@variable_name] = item
-          context['tablerowloop'.freeze] = {
-            'length'.freeze    => length,
-            'index'.freeze     => index + 1,
-            'index0'.freeze    => index,
-            'col'.freeze       => col + 1,
-            'col0'.freeze      => col,
-            'rindex'.freeze    => length - index,
-            'rindex0'.freeze   => length - index - 1,
-            'first'.freeze     => (index == 0),
-            'last'.freeze      => (index == length - 1),
-            'col_first'.freeze => (col == 0),
-            'col_last'.freeze  => (col == cols - 1)
-          }
 
-          col += 1
+          result << "<td class=\"col#{tablerowloop.col}\">" << super << '</td>'
 
-          result << "<td class=\"col#{col}\">" << super << '</td>'
-
-          if col == cols && (index != length - 1)
-            col  = 0
-            row += 1
-            result << "</tr>\n<tr class=\"row#{row}\">"
+          if tablerowloop.col_last && !tablerowloop.last
+            result << "</tr>\n<tr class=\"row#{tablerowloop.row + 1}\">"
           end
+
+          tablerowloop.send(:increment!)
         end
       end
       result << "</tr>\n"

lib/liquid/template.rb

@@ -19,8 +19,10 @@ module Liquid
     @@file_system = BlankFileSystem.new
 
     class TagRegistry
+      include Enumerable
+
       def initialize
-        @tags  = {}
+        @tags = {}
         @cache = {}
       end
 
@@ -41,6 +43,10 @@ module Liquid
         @cache.delete(tag_name)
       end
 
+      def each(&block)
+        @tags.each(&block)
+      end
+
       private
 
       def lookup_class(name)
@@ -80,11 +86,11 @@ module Liquid
       end
 
       def error_mode
-        @error_mode || :lax
+        @error_mode ||= :lax
       end
 
       def taint_mode
-        @taint_mode || :lax
+        @taint_mode ||= :lax
       end
 
       # Pass a module with filter methods which should be available
@@ -107,6 +113,7 @@ module Liquid
     end
 
     def initialize
+      @rethrow_errors = false
       @resource_limits = ResourceLimits.new(self.class.default_resource_limits)
     end
 
@@ -179,20 +186,10 @@ module Liquid
       when Hash
         options = args.pop
 
-        if options[:registers].is_a?(Hash)
-          registers.merge!(options[:registers])
-        end
+        registers.merge!(options[:registers]) if options[:registers].is_a?(Hash)
 
-        if options[:filters]
-          context.add_filters(options[:filters])
-        end
-
-        if options[:exception_handler]
-          context.exception_handler = options[:exception_handler]
-        end
-      when Module
-        context.add_filters(args.pop)
-      when Array
+        apply_options_to_context(context, options)
+      when Module, Array
         context.add_filters(args.pop)
       end
 
@@ -240,5 +237,13 @@ module Liquid
         yield
       end
     end
+
+    def apply_options_to_context(context, options)
+      context.add_filters(options[:filters]) if options[:filters]
+      context.global_filter = options[:global_filter] if options[:global_filter]
+      context.exception_handler = options[:exception_handler] if options[:exception_handler]
+      context.strict_variables = options[:strict_variables] if options[:strict_variables]
+      context.strict_filters = options[:strict_filters] if options[:strict_filters]
+    end
   end
 end

lib/liquid/tokenizer.rb

@@ -4,7 +4,7 @@ module Liquid
 
     def initialize(source, line_numbers = false)
       @source = source
-      @line_number = 1 if line_numbers
+      @line_number = line_numbers ? 1 : nil
       @tokens = tokenize
     end
 

lib/liquid/utils.rb

@@ -50,9 +50,13 @@ module Liquid
       when Numeric
         obj
       when String
-        (obj.strip =~ /\A\d+\.\d+\z/) ? BigDecimal.new(obj) : obj.to_i
+        (obj.strip =~ /\A-?\d+\.\d+\z/) ? BigDecimal.new(obj) : obj.to_i
       else
-        0
+        if obj.respond_to?(:to_number)
+          obj.to_number
+        else
+          0
+        end
       end
     end
 
@@ -72,7 +76,7 @@ module Liquid
       when String
         Time.parse(obj)
       end
-    rescue ArgumentError
+    rescue ::ArgumentError
       nil
     end
   end

lib/liquid/variable.rb

@@ -73,10 +73,16 @@ module Liquid
     end
 
     def render(context)
-      @filters.inject(context.evaluate(@name)) do |output, (filter_name, filter_args, filter_kwargs)|
+      obj = @filters.inject(context.evaluate(@name)) do |output, (filter_name, filter_args, filter_kwargs)|
         filter_args = evaluate_filter_expressions(context, filter_args, filter_kwargs)
         context.invoke(filter_name, output, *filter_args)
-      end.tap{ |obj| taint_check(context, obj) }
+      end
+
+      obj = context.apply_global_filter(obj)
+
+      taint_check(context, obj)
+
+      obj
     end
 
     private

lib/liquid/variable_lookup.rb

@@ -55,9 +55,11 @@ module Liquid
           object = object.send(key).to_liquid
 
           # No key was present with the desired value and it wasn't one of the directly supported
-          # keywords either. The only thing we got left is to return nil
+          # keywords either. The only thing we got left is to return nil or
+          # raise an exception if `strict_variables` option is set to true
         else
-          return nil
+          return nil unless context.strict_variables
+          raise Liquid::UndefinedVariable, "undefined variable #{key}"
         end
 
         # If we are dealing with a drop here we have to

lib/liquid/version.rb

@@ -1,4 +1,4 @@
 # encoding: utf-8
 module Liquid
-  VERSION = "4.0.0.alpha"
+  VERSION = "4.0.0.rc2"
 end

liquid.gemspec

@@ -18,9 +18,9 @@ Gem::Specification.new do |s|
   s.required_rubygems_version = ">= 1.3.7"
 
   s.test_files  = Dir.glob("{test}/**/*")
-  s.files       = Dir.glob("{lib}/**/*") + %w(MIT-LICENSE README.md)
+  s.files       = Dir.glob("{lib}/**/*") + %w(LICENSE README.md)
 
-  s.extra_rdoc_files  = ["History.md", "README.md"]
+  s.extra_rdoc_files = ["History.md", "README.md"]
 
   s.require_path = "lib"
 

test/integration/drop_test.rb

@@ -13,7 +13,7 @@ class ContextDrop < Liquid::Drop
     @context['forloop.index']
   end
 
-  def before_method(method)
+  def liquid_method_missing(method)
     @context[method]
   end
 end
@@ -30,8 +30,8 @@ class ProductDrop < Liquid::Drop
   end
 
   class CatchallDrop < Liquid::Drop
-    def before_method(method)
-      'method: ' << method.to_s
+    def liquid_method_missing(method)
+      'catchall_method: ' << method.to_s
     end
   end
 
@@ -59,7 +59,7 @@ class ProductDrop < Liquid::Drop
 end
 
 class EnumerableDrop < Liquid::Drop
-  def before_method(method)
+  def liquid_method_missing(method)
     method
   end
 
@@ -93,7 +93,7 @@ end
 class RealEnumerableDrop < Liquid::Drop
   include Enumerable
 
-  def before_method(method)
+  def liquid_method_missing(method)
     method
   end
 
@@ -157,14 +157,14 @@ class DropsTest < Minitest::Test
     assert_equal ' text1 ', output
   end
 
-  def test_unknown_method
+  def test_catchall_unknown_method
     output = Liquid::Template.parse(' {{ product.catchall.unknown }} ').render!('product' => ProductDrop.new)
-    assert_equal ' method: unknown ', output
+    assert_equal ' catchall_method: unknown ', output
   end
 
-  def test_integer_argument_drop
+  def test_catchall_integer_argument_drop
     output = Liquid::Template.parse(' {{ product.catchall[8] }} ').render!('product' => ProductDrop.new)
-    assert_equal ' method: 8 ', output
+    assert_equal ' catchall_method: 8 ', output
   end
 
   def test_text_array_drop
@@ -231,7 +231,7 @@ class DropsTest < Minitest::Test
     assert_equal '3', Liquid::Template.parse('{{collection.size}}').render!('collection' => EnumerableDrop.new)
   end
 
-  def test_enumerable_drop_will_invoke_before_method_for_clashing_method_names
+  def test_enumerable_drop_will_invoke_liquid_method_missing_for_clashing_method_names
     ["select", "each", "map", "cycle"].each do |method|
       assert_equal method.to_s, Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => EnumerableDrop.new)
       assert_equal method.to_s, Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => EnumerableDrop.new)

test/integration/error_handling_test.rb

@@ -94,7 +94,7 @@ class ErrorHandlingTest < Minitest::Test
       )
     end
 
-    assert_match /Liquid syntax error \(line 4\)/, err.message
+    assert_match(/Liquid syntax error \(line 4\)/, err.message)
   end
 
   def test_parsing_warn_with_line_numbers_adds_numbers_to_lexer_errors

test/integration/hash_ordering_test.rb

@@ -1,18 +1,18 @@
 require 'test_helper'
 
-module MoneyFilter
-  def money(input)
-    sprintf(' %d$ ', input)
-  end
-end
-
-module CanadianMoneyFilter
-  def money(input)
-    sprintf(' %d$ CAD ', input)
-  end
-end
-
 class HashOrderingTest < Minitest::Test
+  module MoneyFilter
+    def money(input)
+      sprintf(' %d$ ', input)
+    end
+  end
+
+  module CanadianMoneyFilter
+    def money(input)
+      sprintf(' %d$ CAD ', input)
+    end
+  end
+
   include Liquid
 
   def test_global_register_order

test/integration/output_test.rb

@@ -43,6 +43,14 @@ class OutputTest < Minitest::Test
     assert_equal expected, Template.parse(text).render!(@assigns)
   end
 
+  def test_variable_traversing_with_two_brackets
+    text = %({{ site.data.menu[include.menu][include.locale] }})
+    assert_equal "it works!", Template.parse(text).render!(
+      "site" => { "data" => { "menu" => { "foo" => { "bar" => "it works!" } } } },
+      "include" => { "menu" => "foo", "locale" => "bar" }
+    )
+  end
+
   def test_variable_traversing
     text = %( {{car.bmw}} {{car.gm}} {{car.bmw}} )
 

test/integration/security_test.rb

@@ -9,6 +9,10 @@ end
 class SecurityTest < Minitest::Test
   include Liquid
 
+  def setup
+    @assigns = {}
+  end
+
   def test_no_instance_eval
     text = %( {{ '1+1' | instance_eval }} )
     expected = %( 1+1 )

test/integration/standard_filter_test.rb

@@ -41,6 +41,16 @@ class TestEnumerable < Liquid::Drop
   end
 end
 
+class NumberLikeThing < Liquid::Drop
+  def initialize(amount)
+    @amount = amount
+  end
+
+  def to_number
+    @amount
+  end
+end
+
 class StandardFiltersTest < Minitest::Test
   include Liquid
 
@@ -118,6 +128,7 @@ class StandardFiltersTest < Minitest::Test
 
   def test_escape
     assert_equal '&lt;strong&gt;', @filters.escape('<strong>')
+    assert_equal nil, @filters.escape(nil)
     assert_equal '&lt;strong&gt;', @filters.h('<strong>')
   end
 
@@ -130,6 +141,13 @@ class StandardFiltersTest < Minitest::Test
     assert_equal nil, @filters.url_encode(nil)
   end
 
+  def test_url_decode
+    assert_equal 'foo bar', @filters.url_decode('foo+bar')
+    assert_equal 'foo bar', @filters.url_decode('foo%20bar')
+    assert_equal 'foo+1@example.com', @filters.url_decode('foo%2B1%40example.com')
+    assert_equal nil, @filters.url_decode(nil)
+  end
+
   def test_truncatewords
     assert_equal 'one two three', @filters.truncatewords('one two three', 4)
     assert_equal 'one two...', @filters.truncatewords('one two three', 2)
@@ -158,6 +176,14 @@ class StandardFiltersTest < Minitest::Test
     assert_equal [{ "a" => 1 }, { "a" => 2 }, { "a" => 3 }, { "a" => 4 }], @filters.sort([{ "a" => 4 }, { "a" => 3 }, { "a" => 1 }, { "a" => 2 }], "a")
   end
 
+  def test_sort_empty_array
+    assert_equal [], @filters.sort([], "a")
+  end
+
+  def test_sort_natural_empty_array
+    assert_equal [], @filters.sort_natural([], "a")
+  end
+
   def test_legacy_sort_hash
     assert_equal [{ a: 1, b: 2 }], @filters.sort({ a: 1, b: 2 })
   end
@@ -177,6 +203,14 @@ class StandardFiltersTest < Minitest::Test
     assert_equal [testdrop], @filters.uniq([testdrop, TestDrop.new], 'test')
   end
 
+  def test_uniq_empty_array
+    assert_equal [], @filters.uniq([], "a")
+  end
+
+  def test_compact_empty_array
+    assert_equal [], @filters.compact([], "a")
+  end
+
   def test_reverse
     assert_equal [4, 3, 2, 1], @filters.reverse([1, 2, 3, 4])
   end
@@ -225,6 +259,19 @@ class StandardFiltersTest < Minitest::Test
     assert_template_result "testfoo", templ, "procs" => [p]
   end
 
+  def test_map_over_drops_returning_procs
+    drops = [
+      {
+        "proc" => ->{ "foo" },
+      },
+      {
+        "proc" => ->{ "bar" },
+      },
+    ]
+    templ = '{{ drops | map: "proc" }}'
+    assert_template_result "foobar", templ, "drops" => drops
+  end
+
   def test_map_works_on_enumerables
     assert_template_result "123", '{{ foo | map: "foo" }}', "foo" => TestEnumerable.new
   end
@@ -238,6 +285,10 @@ class StandardFiltersTest < Minitest::Test
     assert_template_result 'foobar', '{{ foo | last }}', 'foo' => [ThingWithToLiquid.new]
   end
 
+  def test_truncate_calls_to_liquid
+    assert_template_result "wo...", '{{ foo | truncate: 5 }}', "foo" => TestThing.new
+  end
+
   def test_date
     assert_equal 'May', @filters.date(Time.parse("2006-05-05 10:00:00"), "%B")
     assert_equal 'June', @filters.date(Time.parse("2006-06-05 10:00:00"), "%B")
@@ -263,8 +314,10 @@ class StandardFiltersTest < Minitest::Test
 
     assert_equal '', @filters.date('', "%B")
 
-    assert_equal "07/05/2006", @filters.date(1152098955, "%m/%d/%Y")
-    assert_equal "07/05/2006", @filters.date("1152098955", "%m/%d/%Y")
+    with_timezone("UTC") do
+      assert_equal "07/05/2006", @filters.date(1152098955, "%m/%d/%Y")
+      assert_equal "07/05/2006", @filters.date("1152098955", "%m/%d/%Y")
+    end
   end
 
   def test_first_last
@@ -321,20 +374,38 @@ class StandardFiltersTest < Minitest::Test
   def test_plus
     assert_template_result "2", "{{ 1 | plus:1 }}"
     assert_template_result "2.0", "{{ '1' | plus:'1.0' }}"
+
+    assert_template_result "5", "{{ price | plus:'2' }}", 'price' => NumberLikeThing.new(3)
   end
 
   def test_minus
     assert_template_result "4", "{{ input | minus:operand }}", 'input' => 5, 'operand' => 1
     assert_template_result "2.3", "{{ '4.3' | minus:'2' }}"
+
+    assert_template_result "5", "{{ price | minus:'2' }}", 'price' => NumberLikeThing.new(7)
+  end
+
+  def test_abs
+    assert_template_result "17", "{{ 17 | abs }}"
+    assert_template_result "17", "{{ -17 | abs }}"
+    assert_template_result "17", "{{ '17' | abs }}"
+    assert_template_result "17", "{{ '-17' | abs }}"
+    assert_template_result "0", "{{ 0 | abs }}"
+    assert_template_result "0", "{{ '0' | abs }}"
+    assert_template_result "17.42", "{{ 17.42 | abs }}"
+    assert_template_result "17.42", "{{ -17.42 | abs }}"
+    assert_template_result "17.42", "{{ '17.42' | abs }}"
+    assert_template_result "17.42", "{{ '-17.42' | abs }}"
   end
 
   def test_times
     assert_template_result "12", "{{ 3 | times:4 }}"
     assert_template_result "0", "{{ 'foo' | times:4 }}"
-
     assert_template_result "6", "{{ '2.1' | times:3 | replace: '.','-' | plus:0}}"
-
     assert_template_result "7.25", "{{ 0.0725 | times:100 }}"
+    assert_template_result "-7.25", '{{ "-0.0725" | times:100 }}'
+    assert_template_result "7.25", '{{ "-0.0725" | times: -100 }}'
+    assert_template_result "4", "{{ price | times:2 }}", 'price' => NumberLikeThing.new(2)
   end
 
   def test_divided_by
@@ -348,6 +419,8 @@ class StandardFiltersTest < Minitest::Test
     assert_raises(Liquid::ZeroDivisionError) do
       assert_template_result "4", "{{ 1 | modulo: 0 }}"
     end
+
+    assert_template_result "5", "{{ price | divided_by:2 }}", 'price' => NumberLikeThing.new(10)
   end
 
   def test_modulo
@@ -355,6 +428,8 @@ class StandardFiltersTest < Minitest::Test
     assert_raises(Liquid::ZeroDivisionError) do
       assert_template_result "4", "{{ 1 | modulo: 0 }}"
     end
+
+    assert_template_result "1", "{{ price | modulo:2 }}", 'price' => NumberLikeThing.new(3)
   end
 
   def test_round
@@ -364,6 +439,9 @@ class StandardFiltersTest < Minitest::Test
     assert_raises(Liquid::FloatDomainError) do
       assert_template_result "4", "{{ 1.0 | divided_by: 0.0 | round }}"
     end
+
+    assert_template_result "5", "{{ price | round }}", 'price' => NumberLikeThing.new(4.6)
+    assert_template_result "4", "{{ price | round }}", 'price' => NumberLikeThing.new(4.3)
   end
 
   def test_ceil
@@ -372,6 +450,8 @@ class StandardFiltersTest < Minitest::Test
     assert_raises(Liquid::FloatDomainError) do
       assert_template_result "4", "{{ 1.0 | divided_by: 0.0 | ceil }}"
     end
+
+    assert_template_result "5", "{{ price | ceil }}", 'price' => NumberLikeThing.new(4.6)
   end
 
   def test_floor
@@ -380,6 +460,8 @@ class StandardFiltersTest < Minitest::Test
     assert_raises(Liquid::FloatDomainError) do
       assert_template_result "4", "{{ 1.0 | divided_by: 0.0 | floor }}"
     end
+
+    assert_template_result "5", "{{ price | floor }}", 'price' => NumberLikeThing.new(5.4)
   end
 
   def test_append
@@ -393,8 +475,7 @@ class StandardFiltersTest < Minitest::Test
     assert_equal [1, 2, 'a'],  @filters.concat([1, 2], ['a'])
     assert_equal [1, 2, 10],   @filters.concat([1, 2], [10])
 
-    assert_raises(TypeError) do
-      # no implicit conversion of Fixnum into Array
+    assert_raises(Liquid::ArgumentError, "concat filter requires an array argument") do
       @filters.concat([1, 2], 10)
     end
   end
@@ -417,4 +498,19 @@ class StandardFiltersTest < Minitest::Test
   def test_cannot_access_private_methods
     assert_template_result('a', "{{ 'a' | to_number }}")
   end
+
+  def test_date_raises_nothing
+    assert_template_result('', "{{ '' | date: '%D' }}")
+    assert_template_result('abc', "{{ 'abc' | date: '%D' }}")
+  end
+
+  private
+
+  def with_timezone(tz)
+    old_tz = ENV['TZ']
+    ENV['TZ'] = tz
+    yield
+  ensure
+    ENV['TZ'] = old_tz
+  end
 end # StandardFiltersTest

test/integration/tags/if_else_tag_test.rb

@@ -29,10 +29,10 @@ class IfElseTagTest < Minitest::Test
     assert_template_result(' YES ', '{% if a or b %} YES {% endif %}', 'a' => true, 'b' => true)
     assert_template_result(' YES ', '{% if a or b %} YES {% endif %}', 'a' => true, 'b' => false)
     assert_template_result(' YES ', '{% if a or b %} YES {% endif %}', 'a' => false, 'b' => true)
-    assert_template_result('',     '{% if a or b %} YES {% endif %}', 'a' => false, 'b' => false)
+    assert_template_result('',      '{% if a or b %} YES {% endif %}', 'a' => false, 'b' => false)
 
     assert_template_result(' YES ', '{% if a or b or c %} YES {% endif %}', 'a' => false, 'b' => false, 'c' => true)
-    assert_template_result('',     '{% if a or b or c %} YES {% endif %}', 'a' => false, 'b' => false, 'c' => false)
+    assert_template_result('',      '{% if a or b or c %} YES {% endif %}', 'a' => false, 'b' => false, 'c' => false)
   end
 
   def test_if_or_with_operators

test/integration/tags/raw_tag_test.rb

@@ -24,8 +24,8 @@ class RawTagTest < Minitest::Test
   end
 
   def test_invalid_raw
-    assert_match_syntax_error /tag was never closed/, '{% raw %} foo'
-    assert_match_syntax_error /Valid syntax/, '{% raw } foo {% endraw %}'
-    assert_match_syntax_error /Valid syntax/, '{% raw } foo %}{% endraw %}'
+    assert_match_syntax_error(/tag was never closed/, '{% raw %} foo')
+    assert_match_syntax_error(/Valid syntax/, '{% raw } foo {% endraw %}')
+    assert_match_syntax_error(/Valid syntax/, '{% raw } foo %}{% endraw %}')
   end
 end

test/integration/template_test.rb

@@ -2,7 +2,7 @@ require 'test_helper'
 require 'timeout'
 
 class TemplateContextDrop < Liquid::Drop
-  def before_method(method)
+  def liquid_method_missing(method)
     method
   end
 
@@ -27,6 +27,12 @@ class ErroneousDrop < Liquid::Drop
   end
 end
 
+class DropWithUndefinedMethod < Liquid::Drop
+  def foo
+    'foo'
+  end
+end
+
 class TemplateTest < Minitest::Test
   include Liquid
 
@@ -133,6 +139,17 @@ class TemplateTest < Minitest::Test
     refute_nil t.resource_limits.assign_score
   end
 
+  def test_resource_limits_assign_score_nested
+    t = Template.parse("{% assign foo = 'aaaa' | reverse %}")
+
+    t.resource_limits.assign_score_limit = 3
+    assert_equal "Liquid error: Memory limits exceeded", t.render
+    assert t.resource_limits.reached?
+
+    t.resource_limits.assign_score_limit = 5
+    assert_equal "", t.render!
+  end
+
   def test_resource_limits_aborts_rendering_after_first_error
     t = Template.parse("{% for a in (1..100) %} foo1 {% endfor %} bar {% for a in (1..100) %} foo2 {% endfor %}")
     t.resource_limits.render_score_limit = 50
@@ -211,4 +228,92 @@ class TemplateTest < Minitest::Test
     end
     assert exception.is_a?(Liquid::ZeroDivisionError)
   end
+
+  def test_global_filter_option_on_render
+    global_filter_proc = ->(output) { "#{output} filtered" }
+    rendered_template = Template.parse("{{name}}").render({ "name" => "bob" }, global_filter: global_filter_proc)
+
+    assert_equal 'bob filtered', rendered_template
+  end
+
+  def test_global_filter_option_when_native_filters_exist
+    global_filter_proc = ->(output) { "#{output} filtered" }
+    rendered_template = Template.parse("{{name | upcase}}").render({ "name" => "bob" }, global_filter: global_filter_proc)
+
+    assert_equal 'BOB filtered', rendered_template
+  end
+
+  def test_undefined_variables
+    t = Template.parse("{{x}} {{y}} {{z.a}} {{z.b}} {{z.c.d}}")
+    result = t.render({ 'x' => 33, 'z' => { 'a' => 32, 'c' => { 'e' => 31 } } }, { strict_variables: true })
+
+    assert_equal '33  32  ', result
+    assert_equal 3, t.errors.count
+    assert_instance_of Liquid::UndefinedVariable, t.errors[0]
+    assert_equal 'Liquid error: undefined variable y', t.errors[0].message
+    assert_instance_of Liquid::UndefinedVariable, t.errors[1]
+    assert_equal 'Liquid error: undefined variable b', t.errors[1].message
+    assert_instance_of Liquid::UndefinedVariable, t.errors[2]
+    assert_equal 'Liquid error: undefined variable d', t.errors[2].message
+  end
+
+  def test_undefined_variables_raise
+    t = Template.parse("{{x}} {{y}} {{z.a}} {{z.b}} {{z.c.d}}")
+
+    assert_raises UndefinedVariable do
+      t.render!({ 'x' => 33, 'z' => { 'a' => 32, 'c' => { 'e' => 31 } } }, { strict_variables: true })
+    end
+  end
+
+  def test_undefined_drop_methods
+    d = DropWithUndefinedMethod.new
+    t = Template.new.parse('{{ foo }} {{ woot }}')
+    result = t.render(d, { strict_variables: true })
+
+    assert_equal 'foo ', result
+    assert_equal 1, t.errors.count
+    assert_instance_of Liquid::UndefinedDropMethod, t.errors[0]
+  end
+
+  def test_undefined_drop_methods_raise
+    d = DropWithUndefinedMethod.new
+    t = Template.new.parse('{{ foo }} {{ woot }}')
+
+    assert_raises UndefinedDropMethod do
+      t.render!(d, { strict_variables: true })
+    end
+  end
+
+  def test_undefined_filters
+    t = Template.parse("{{a}} {{x | upcase | somefilter1 | somefilter2 | somefilter3}}")
+    filters = Module.new do
+      def somefilter3(v)
+        "-#{v}-"
+      end
+    end
+    result = t.render({ 'a' => 123, 'x' => 'foo' }, { filters: [filters], strict_filters: true })
+
+    assert_equal '123 ', result
+    assert_equal 1, t.errors.count
+    assert_instance_of Liquid::UndefinedFilter, t.errors[0]
+    assert_equal 'Liquid error: undefined filter somefilter1', t.errors[0].message
+  end
+
+  def test_undefined_filters_raise
+    t = Template.parse("{{x | somefilter1 | upcase | somefilter2}}")
+
+    assert_raises UndefinedFilter do
+      t.render!({ 'x' => 'foo' }, { strict_filters: true })
+    end
+  end
+
+  def test_using_range_literal_works_as_expected
+    t = Template.parse("{% assign foo = (x..y) %}{{ foo }}")
+    result = t.render({ 'x' => 1, 'y' => 5 })
+    assert_equal '1..5', result
+
+    t = Template.parse("{% assign nums = (x..y) %}{% for num in nums %}{{ num }}{% endfor %}")
+    result = t.render({ 'x' => 1, 'y' => 5 })
+    assert_equal '12345', result
+  end
 end

test/unit/block_unit_test.rb

@@ -46,6 +46,8 @@ class BlockUnitTest < Minitest::Test
   def test_with_custom_tag
     Liquid::Template.register_tag("testtag", Block)
     assert Liquid::Template.parse("{% testtag %} {% endtesttag %}")
+  ensure
+    Liquid::Template.tags.delete('testtag')
   end
 
   private

test/unit/condition_unit_test.rb

@@ -3,50 +3,54 @@ require 'test_helper'
 class ConditionUnitTest < Minitest::Test
   include Liquid
 
+  def setup
+    @context = Liquid::Context.new
+  end
+
   def test_basic_condition
     assert_equal false, Condition.new(1, '==', 2).evaluate
     assert_equal true,  Condition.new(1, '==', 1).evaluate
   end
 
   def test_default_operators_evalute_true
-    assert_evalutes_true 1, '==', 1
-    assert_evalutes_true 1, '!=', 2
-    assert_evalutes_true 1, '<>', 2
-    assert_evalutes_true 1, '<', 2
-    assert_evalutes_true 2, '>', 1
-    assert_evalutes_true 1, '>=', 1
-    assert_evalutes_true 2, '>=', 1
-    assert_evalutes_true 1, '<=', 2
-    assert_evalutes_true 1, '<=', 1
+    assert_evaluates_true 1, '==', 1
+    assert_evaluates_true 1, '!=', 2
+    assert_evaluates_true 1, '<>', 2
+    assert_evaluates_true 1, '<', 2
+    assert_evaluates_true 2, '>', 1
+    assert_evaluates_true 1, '>=', 1
+    assert_evaluates_true 2, '>=', 1
+    assert_evaluates_true 1, '<=', 2
+    assert_evaluates_true 1, '<=', 1
     # negative numbers
-    assert_evalutes_true 1, '>', -1
-    assert_evalutes_true -1, '<', 1
-    assert_evalutes_true 1.0, '>', -1.0
-    assert_evalutes_true -1.0, '<', 1.0
+    assert_evaluates_true 1, '>', -1
+    assert_evaluates_true (-1), '<', 1
+    assert_evaluates_true 1.0, '>', -1.0
+    assert_evaluates_true (-1.0), '<', 1.0
   end
 
   def test_default_operators_evalute_false
-    assert_evalutes_false 1, '==', 2
-    assert_evalutes_false 1, '!=', 1
-    assert_evalutes_false 1, '<>', 1
-    assert_evalutes_false 1, '<', 0
-    assert_evalutes_false 2, '>', 4
-    assert_evalutes_false 1, '>=', 3
-    assert_evalutes_false 2, '>=', 4
-    assert_evalutes_false 1, '<=', 0
-    assert_evalutes_false 1, '<=', 0
+    assert_evaluates_false 1, '==', 2
+    assert_evaluates_false 1, '!=', 1
+    assert_evaluates_false 1, '<>', 1
+    assert_evaluates_false 1, '<', 0
+    assert_evaluates_false 2, '>', 4
+    assert_evaluates_false 1, '>=', 3
+    assert_evaluates_false 2, '>=', 4
+    assert_evaluates_false 1, '<=', 0
+    assert_evaluates_false 1, '<=', 0
   end
 
   def test_contains_works_on_strings
-    assert_evalutes_true 'bob', 'contains', 'o'
-    assert_evalutes_true 'bob', 'contains', 'b'
-    assert_evalutes_true 'bob', 'contains', 'bo'
-    assert_evalutes_true 'bob', 'contains', 'ob'
-    assert_evalutes_true 'bob', 'contains', 'bob'
+    assert_evaluates_true 'bob', 'contains', 'o'
+    assert_evaluates_true 'bob', 'contains', 'b'
+    assert_evaluates_true 'bob', 'contains', 'bo'
+    assert_evaluates_true 'bob', 'contains', 'ob'
+    assert_evaluates_true 'bob', 'contains', 'bob'
 
-    assert_evalutes_false 'bob', 'contains', 'bob2'
-    assert_evalutes_false 'bob', 'contains', 'a'
-    assert_evalutes_false 'bob', 'contains', '---'
+    assert_evaluates_false 'bob', 'contains', 'bob2'
+    assert_evaluates_false 'bob', 'contains', 'a'
+    assert_evaluates_false 'bob', 'contains', '---'
   end
 
   def test_invalid_comparation_operator
@@ -65,29 +69,29 @@ class ConditionUnitTest < Minitest::Test
     @context['array'] = [1, 2, 3, 4, 5]
     array_expr = VariableLookup.new("array")
 
-    assert_evalutes_false array_expr, 'contains', 0
-    assert_evalutes_true array_expr, 'contains', 1
-    assert_evalutes_true array_expr, 'contains', 2
-    assert_evalutes_true array_expr, 'contains', 3
-    assert_evalutes_true array_expr, 'contains', 4
-    assert_evalutes_true array_expr, 'contains', 5
-    assert_evalutes_false array_expr, 'contains', 6
-    assert_evalutes_false array_expr, 'contains', "1"
+    assert_evaluates_false array_expr, 'contains', 0
+    assert_evaluates_true array_expr, 'contains', 1
+    assert_evaluates_true array_expr, 'contains', 2
+    assert_evaluates_true array_expr, 'contains', 3
+    assert_evaluates_true array_expr, 'contains', 4
+    assert_evaluates_true array_expr, 'contains', 5
+    assert_evaluates_false array_expr, 'contains', 6
+    assert_evaluates_false array_expr, 'contains', "1"
   end
 
   def test_contains_returns_false_for_nil_operands
     @context = Liquid::Context.new
-    assert_evalutes_false VariableLookup.new('not_assigned'), 'contains', '0'
-    assert_evalutes_false 0, 'contains', VariableLookup.new('not_assigned')
+    assert_evaluates_false VariableLookup.new('not_assigned'), 'contains', '0'
+    assert_evaluates_false 0, 'contains', VariableLookup.new('not_assigned')
   end
 
   def test_contains_return_false_on_wrong_data_type
-    assert_evalutes_false 1, 'contains', 0
+    assert_evaluates_false 1, 'contains', 0
   end
 
   def test_contains_with_string_left_operand_coerces_right_operand_to_string
-    assert_evalutes_true ' 1 ', 'contains', 1
-    assert_evalutes_false ' 1 ', 'contains', 2
+    assert_evaluates_true ' 1 ', 'contains', 1
+    assert_evaluates_false ' 1 ', 'contains', 2
   end
 
   def test_or_condition
@@ -121,8 +125,8 @@ class ConditionUnitTest < Minitest::Test
   def test_should_allow_custom_proc_operator
     Condition.operators['starts_with'] = proc { |cond, left, right| left =~ %r{^#{right}} }
 
-    assert_evalutes_true 'bob', 'starts_with', 'b'
-    assert_evalutes_false 'bob', 'starts_with', 'o'
+    assert_evaluates_true 'bob', 'starts_with', 'b'
+    assert_evaluates_false 'bob', 'starts_with', 'o'
   ensure
     Condition.operators.delete 'starts_with'
   end
@@ -131,24 +135,24 @@ class ConditionUnitTest < Minitest::Test
     @context = Liquid::Context.new
     @context['one'] = @context['another'] = "gnomeslab-and-or-liquid"
 
-    assert_evalutes_true VariableLookup.new("one"), '==', VariableLookup.new("another")
+    assert_evaluates_true VariableLookup.new("one"), '==', VariableLookup.new("another")
   end
 
   private
 
-  def assert_evalutes_true(left, op, right)
-    assert Condition.new(left, op, right).evaluate(@context || Liquid::Context.new),
+  def assert_evaluates_true(left, op, right)
+    assert Condition.new(left, op, right).evaluate(@context),
       "Evaluated false: #{left} #{op} #{right}"
   end
 
-  def assert_evalutes_false(left, op, right)
-    assert !Condition.new(left, op, right).evaluate(@context || Liquid::Context.new),
+  def assert_evaluates_false(left, op, right)
+    assert !Condition.new(left, op, right).evaluate(@context),
       "Evaluated true: #{left} #{op} #{right}"
   end
 
   def assert_evaluates_argument_error(left, op, right)
     assert_raises(Liquid::ArgumentError) do
-      Condition.new(left, op, right).evaluate(@context || Liquid::Context.new)
+      Condition.new(left, op, right).evaluate(@context)
     end
   end
 end # ConditionTest

test/unit/context_unit_test.rb

@@ -267,7 +267,7 @@ class ContextUnitTest < Minitest::Test
 
   def test_access_hashes_with_hash_notation
     @context['products'] = { 'count' => 5, 'tags' => ['deepsnow', 'freestyle'] }
-    @context['product'] = { 'variants' => [ { 'title' => 'draft151cm' }, { 'title' => 'element151cm' }  ] }
+    @context['product'] = { 'variants' => [ { 'title' => 'draft151cm' }, { 'title' => 'element151cm' } ] }
 
     assert_equal 5, @context['products["count"]']
     assert_equal 'deepsnow', @context['products["tags"][0]']
@@ -305,7 +305,7 @@ class ContextUnitTest < Minitest::Test
   end
 
   def test_first_can_appear_in_middle_of_callchain
-    @context['product'] = { 'variants' => [ { 'title' => 'draft151cm' }, { 'title' => 'element151cm' }  ] }
+    @context['product'] = { 'variants' => [ { 'title' => 'draft151cm' }, { 'title' => 'element151cm' } ] }
 
     assert_equal 'draft151cm', @context['product.variants[0].title']
     assert_equal 'element151cm', @context['product.variants[1].title']
@@ -466,4 +466,18 @@ class ContextUnitTest < Minitest::Test
     assert contx
     assert_nil contx['poutine']
   end
+
+  def test_apply_global_filter
+    global_filter_proc = ->(output) { "#{output} filtered" }
+
+    context = Context.new
+    context.global_filter = global_filter_proc
+
+    assert_equal 'hi filtered', context.apply_global_filter('hi')
+  end
+
+  def test_apply_global_filter_when_no_global_filter_exist
+    context = Context.new
+    assert_equal 'hi', context.apply_global_filter('hi')
+  end
 end # ContextTest

test/unit/strainer_unit_test.rb

@@ -29,6 +29,18 @@ class StrainerUnitTest < Minitest::Test
     end
   end
 
+  def test_stainer_argument_error_contains_backtrace
+    strainer = Strainer.create(nil)
+    begin
+      strainer.invoke("public_filter", 1)
+    rescue Liquid::ArgumentError => e
+      assert_match(
+        /\ALiquid error: wrong number of arguments \((1 for 0|given 1, expected 0)\)\z/,
+        e.message)
+      assert_equal e.backtrace[0].split(':')[0], __FILE__
+    end
+  end
+
   def test_strainer_only_invokes_public_filter_methods
     strainer = Strainer.create(nil)
     assert_equal false, strainer.class.invokable?('__test__')
@@ -65,4 +77,60 @@ class StrainerUnitTest < Minitest::Test
     assert_kind_of b, strainer
     assert_kind_of Liquid::StandardFilters, strainer
   end
+
+  def test_add_filter_when_wrong_filter_class
+    c = Context.new
+    s = c.strainer
+    wrong_filter = ->(v) { v.reverse }
+
+    assert_raises ArgumentError do
+      s.class.add_filter(wrong_filter)
+    end
+  end
+
+  module PrivateMethodOverrideFilter
+    private
+
+    def public_filter
+      "overriden as private"
+    end
+  end
+
+  def test_add_filter_raises_when_module_privately_overrides_registered_public_methods
+    strainer = Context.new.strainer
+
+    error = assert_raises(Liquid::MethodOverrideError) do
+      strainer.class.add_filter(PrivateMethodOverrideFilter)
+    end
+    assert_equal 'Liquid error: Filter overrides registered public methods as non public: public_filter', error.message
+  end
+
+  module ProtectedMethodOverrideFilter
+    protected
+
+    def public_filter
+      "overriden as protected"
+    end
+  end
+
+  def test_add_filter_raises_when_module_overrides_registered_public_method_as_protected
+    strainer = Context.new.strainer
+
+    error = assert_raises(Liquid::MethodOverrideError) do
+      strainer.class.add_filter(ProtectedMethodOverrideFilter)
+    end
+    assert_equal 'Liquid error: Filter overrides registered public methods as non public: public_filter', error.message
+  end
+
+  module PublicMethodOverrideFilter
+    def public_filter
+      "public"
+    end
+  end
+
+  def test_add_filter_does_not_raise_when_module_overrides_previously_registered_method
+    strainer = Context.new.strainer
+    strainer.class.add_filter(PublicMethodOverrideFilter)
+    assert strainer.class.filter_methods.include?('public_filter')
+  end
 end # StrainerTest

test/unit/template_unit_test.rb

@@ -67,4 +67,12 @@ class TemplateUnitTest < Minitest::Test
     Template.tags.delete('fake')
     assert_nil Template.tags['fake']
   end
+
+  def test_tags_can_be_looped_over
+    Template.register_tag('fake', FakeTag)
+    result = Template.tags.map { |name, klass| [name, klass] }
+    assert result.include?(["fake", "TemplateUnitTest::FakeTag"])
+  ensure
+    Template.tags.delete('fake')
+  end
 end