refactor: Reduce maximum block nesting in Liquid::BlockBody#parse

Avoid hash with default values due to inconsistent marshaling

.rubocop.yml

@@ -7,12 +7,13 @@ AllCops:
 
 Metrics/BlockNesting:
   Max: 3
-  Exclude:
-    - 'lib/liquid/block_body.rb'
 
 Metrics/ModuleLength:
   Enabled: false
 
+Metrics/ClassLength:
+  Enabled: false
+
 Lint/AssignmentInCondition:
   Enabled: false
 
@@ -115,9 +116,8 @@ Style/ClassVars:
 Style/PerlBackrefs:
   Enabled: false
 
+Style/TrivialAccessors:
+  AllowPredicates: true
+
 Style/WordArray:
   Enabled: false
-
-Style/ModuleLength:
-  Exclude:
-    - lib/liquid/standardfilters.rb

.rubocop_todo.yml

@@ -13,11 +13,6 @@ Lint/NestedMethodDefinition:
 Metrics/AbcSize:
   Max: 58
 
-# Offense count: 16
-# Configuration parameters: CountComments.
-Metrics/ClassLength:
-  Max: 314
-
 # Offense count: 12
 Metrics/CyclomaticComplexity:
   Max: 15
@@ -32,11 +27,6 @@ Metrics/LineLength:
 Metrics/MethodLength:
   Max: 46
 
-# Offense count: 1
-# Configuration parameters: CountComments.
-Metrics/ModuleLength:
-  Max: 235
-
 # Offense count: 6
 Metrics/PerceivedComplexity:
   Max: 13

.travis.yml

@@ -1,19 +1,28 @@
 language: ruby
 
 rvm:
-  - 2.0
   - 2.1
   - 2.2
+  - 2.3.3
   - ruby-head
   - jruby-head
-  - rbx-2
+#  - rbx-2
 
 sudo: false
 
+addons:
+  apt:
+    packages:
+    - libgmp3-dev
+
 matrix:
   allow_failures:
     - rvm: jruby-head
 
+install:
+  - gem install rainbow -v 2.2.1
+  - bundle install
+
 script: "bundle exec rake"
 
 notifications:

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

@@ -1,14 +1,17 @@
 source 'https://rubygems.org'
 
 gemspec
-gem 'stackprof', platforms: :mri_21
+
+gem 'stackprof', platforms: :mri
+
+group :benchmark, :test do
+  gem 'benchmark-ips'
+end
 
 group :test do
-  gem 'spy', '0.4.1'
-  gem 'benchmark-ips'
-  gem 'rubocop'
+  gem 'rubocop', '0.34.2'
 
   platform :mri do
-    gem 'liquid-c', github: 'Shopify/liquid-c', ref: '35e9aee48d639ae1d3ac9ba77616aca9800eab7d'
+    gem 'liquid-c', github: 'Shopify/liquid-c', ref: 'bd53db95de3d44d631e7c5a267c3d934e66107dd'
   end
 end

History.md

@@ -1,8 +1,16 @@
 # Liquid Change Log
 
-## 4.0.0 / not yet released / branch "master"
+## 4.0.0 / 2016-12-14 / branch "4-0-stable"
 
 ### Changed
+* Render an opaque internal error by default for non-Liquid::Error (#835) [Dylan Thacker-Smith]
+* Ruby 2.0 support dropped (#832) [Dylan Thacker-Smith]
+* 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]
@@ -12,9 +20,18 @@
 * Add concat filter to concatenate arrays (#429) [Diogo Beato]
 * 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`
+* Remove `liquid_methods` (See https://github.com/Shopify/liquid/pull/568 for replacement)
+* Liquid::Template.register_filter raises when the module overrides registered public methods as private or protected (#705) [Gaurav Chande]
 
 ### Fixed
+
+* Fix variable names being detected as an operator when starting with contains (#788) [Michael Angell]
+* Fix include tag used with strict_variables (#828) [QuickPay]
+* 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 +43,15 @@
 * 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 +99,15 @@
 * 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
+```

circle.yml

@@ -1,3 +1,3 @@
 machine:
   ruby:
-    version: ruby-2.0
+    version: ruby-2.1

lib/liquid.rb

@@ -24,6 +24,7 @@ module Liquid
   ArgumentSeparator           = ','.freeze
   FilterArgumentSeparator     = ':'.freeze
   VariableAttributeSeparator  = '.'.freeze
+  WhitespaceControl           = '-'.freeze
   TagStart                    = /\{\%/
   TagEnd                      = /\%\}/
   VariableSignature           = /\(?[\w\-\.\[\]]\)?/
@@ -34,7 +35,7 @@ module Liquid
   QuotedString                = /"[^"]*"|'[^']*'/
   QuotedFragment              = /#{QuotedString}|(?:[^\s,\|'"]|#{QuotedString})+/o
   TagAttributes               = /(\w+)\s*\:\s*(#{QuotedFragment})/o
-  AnyStartingTag              = /\{\{|\{\%/
+  AnyStartingTag              = /#{TagStart}|#{VariableStart}/o
   PartialTemplateParser       = /#{TagStart}.*?#{TagEnd}|#{VariableStart}.*?#{VariableIncompleteEnd}/om
   TemplateParser              = /(#{PartialTemplateParser}|#{AnyStartingTag})/om
   VariableParser              = /\[[^\]]+\]|#{VariableSegment}+\??/o
@@ -48,6 +49,8 @@ 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'
@@ -69,7 +72,7 @@ require 'liquid/standardfilters'
 require 'liquid/condition'
 require 'liquid/utils'
 require 'liquid/tokenizer'
-require 'liquid/token'
+require 'liquid/parse_context'
 
 # Load all the tags of the standard library
 #

lib/liquid/block.rb

@@ -1,5 +1,7 @@
 module Liquid
   class Block < Tag
+    MAX_DEPTH = 100
+
     def initialize(tag_name, markup, options)
       super
       @blank = true
@@ -23,29 +25,17 @@ module Liquid
       @body.nodelist
     end
 
-    # warnings of this block and all sub-tags
-    def warnings
-      all_warnings = []
-      all_warnings.concat(@warnings) if @warnings
-
-      (nodelist || []).each do |node|
-        all_warnings.concat(node.warnings || []) if node.respond_to?(:warnings)
-      end
-
-      all_warnings
-    end
-
     def unknown_tag(tag, _params, _tokens)
       case tag
       when 'else'.freeze
-        raise SyntaxError.new(options[:locale].t("errors.syntax.unexpected_else".freeze,
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unexpected_else".freeze,
           block_name: block_name))
       when 'end'.freeze
-        raise SyntaxError.new(options[:locale].t("errors.syntax.invalid_delimiter".freeze,
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.invalid_delimiter".freeze,
           block_name: block_name,
           block_delimiter: block_delimiter))
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.unknown_tag".freeze, tag: tag))
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unknown_tag".freeze, tag: tag))
       end
     end
 
@@ -60,17 +50,25 @@ module Liquid
     protected
 
     def parse_body(body, tokens)
-      body.parse(tokens, options) do |end_tag_name, end_tag_params|
-        @blank &&= body.blank?
+      if parse_context.depth >= MAX_DEPTH
+        raise StackLevelError, "Nesting too deep".freeze
+      end
+      parse_context.depth += 1
+      begin
+        body.parse(tokens, parse_context) do |end_tag_name, end_tag_params|
+          @blank &&= body.blank?
 
-        return false if end_tag_name == block_delimiter
-        unless end_tag_name
-          raise SyntaxError.new(@options[:locale].t("errors.syntax.tag_never_closed".freeze, block_name: block_name))
+          return false if end_tag_name == block_delimiter
+          unless end_tag_name
+            raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_never_closed".freeze, block_name: block_name))
+          end
+
+          # this tag is not registered with the system
+          # pass it to the current block for special handling or error reporting
+          unknown_tag(end_tag_name, end_tag_params, tokens)
         end
-
-        # this tag is not registered with the system
-        # pass it to the current block for special handling or error reporting
-        unknown_tag(end_tag_name, end_tag_params, tokens)
+      ensure
+        parse_context.depth -= 1
       end
 
       true

lib/liquid/block_body.rb

@@ -1,7 +1,7 @@
 module Liquid
   class BlockBody
-    FullToken = /\A#{TagStart}\s*(\w+)\s*(.*)?#{TagEnd}\z/om
-    ContentOfVariable = /\A#{VariableStart}(.*)#{VariableEnd}\z/om
+    FullToken = /\A#{TagStart}#{WhitespaceControl}?\s*(\w+)\s*(.*?)#{WhitespaceControl}?#{TagEnd}\z/om
+    ContentOfVariable = /\A#{VariableStart}#{WhitespaceControl}?(.*?)#{WhitespaceControl}?#{VariableEnd}\z/om
     TAGSTART = "{%".freeze
     VARSTART = "{{".freeze
 
@@ -12,59 +12,57 @@ module Liquid
       @blank = true
     end
 
-    def parse(tokens, options)
-      while token = tokens.shift
-        begin
-          unless token.empty?
-            case
-            when token.start_with?(TAGSTART)
-              if token =~ FullToken
-                tag_name = $1
-                markup = $2
-                # fetch the tag from registered blocks
-                if tag = registered_tags[tag_name]
-                  markup = token.child(markup) if token.is_a?(Token)
-                  new_tag = tag.parse(tag_name, markup, tokens, options)
-                  new_tag.line_number = token.line_number if token.is_a?(Token)
-                  @blank &&= new_tag.blank?
-                  @nodelist << new_tag
-                else
-                  # end parsing if we reach an unknown tag and let the caller decide
-                  # determine how to proceed
-                  return yield tag_name, markup
-                end
-              else
-                raise_missing_tag_terminator(token, options)
-              end
-            when token.start_with?(VARSTART)
-              new_var = create_variable(token, options)
-              new_var.line_number = token.line_number if token.is_a?(Token)
-              @nodelist << new_var
-              @blank = false
-            else
-              @nodelist << token
-              @blank &&= !!(token =~ /\A\s*\z/)
-            end
+    def parse(tokenizer, parse_context)
+      parse_context.line_number = tokenizer.line_number
+      while token = tokenizer.shift
+        next if token.empty?
+        case
+        when token.start_with?(TAGSTART)
+          whitespace_handler(token, parse_context)
+          unless token =~ FullToken
+            raise_missing_tag_terminator(token, parse_context)
           end
-        rescue SyntaxError => e
-          e.set_line_number_from_token(token)
-          raise
+          tag_name = $1
+          markup = $2
+          # fetch the tag from registered blocks
+          unless tag = registered_tags[tag_name]
+            # end parsing if we reach an unknown tag and let the caller decide
+            # determine how to proceed
+            return yield tag_name, markup
+          end
+          new_tag = tag.parse(tag_name, markup, tokenizer, parse_context)
+          @blank &&= new_tag.blank?
+          @nodelist << new_tag
+        when token.start_with?(VARSTART)
+          whitespace_handler(token, parse_context)
+          @nodelist << create_variable(token, parse_context)
+          @blank = false
+        else
+          if parse_context.trim_whitespace
+            token.lstrip!
+          end
+          parse_context.trim_whitespace = false
+          @nodelist << token
+          @blank &&= !!(token =~ /\A\s*\z/)
         end
+        parse_context.line_number = tokenizer.line_number
       end
 
       yield nil, nil
     end
 
-    def blank?
-      @blank
+    def whitespace_handler(token, parse_context)
+      if token[2] == WhitespaceControl
+        previous_token = @nodelist.last
+        if previous_token.is_a? String
+          previous_token.rstrip!
+        end
+      end
+      parse_context.trim_whitespace = (token[-3] == WhitespaceControl)
     end
 
-    def warnings
-      all_warnings = []
-      nodelist.each do |node|
-        all_warnings.concat(node.warnings || []) if node.respond_to?(:warnings)
-      end
-      all_warnings
+    def blank?
+      @blank
     end
 
     def render(context)
@@ -84,15 +82,19 @@ module Liquid
             break
           end
 
-          token_output = render_token(token, context)
+          node_output = render_node(token, context)
 
           unless token.is_a?(Block) && token.blank?
-            output << token_output
+            output << node_output
           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 = token.is_a?(String) ? nil : token.line_number
+          output << context.handle_error(e, line_number)
         end
       end
 
@@ -101,31 +103,31 @@ module Liquid
 
     private
 
-    def render_token(token, context)
-      token_output = (token.respond_to?(:render) ? token.render(context) : token)
-      token_str = token_output.is_a?(Array) ? token_output.join : token_output.to_s
+    def render_node(node, context)
+      node_output = node.is_a?(String) ? node : node.render(context)
+      node_output = node_output.is_a?(Array) ? node_output.join : node_output.to_s
 
-      context.resource_limits.render_length += token_str.length
+      context.resource_limits.render_length += node_output.length
       if context.resource_limits.reached?
         raise MemoryError.new("Memory limits exceeded".freeze)
       end
-      token_str
+      node_output
     end
 
-    def create_variable(token, options)
+    def create_variable(token, parse_context)
       token.scan(ContentOfVariable) do |content|
-        markup = token.is_a?(Token) ? token.child(content.first) : content.first
-        return Variable.new(markup, options)
+        markup = content.first
+        return Variable.new(markup, parse_context)
       end
-      raise_missing_variable_terminator(token, options)
+      raise_missing_variable_terminator(token, parse_context)
     end
 
-    def raise_missing_tag_terminator(token, options)
-      raise SyntaxError.new(options[:locale].t("errors.syntax.tag_termination".freeze, token: token, tag_end: TagEnd.inspect))
+    def raise_missing_tag_terminator(token, parse_context)
+      raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_termination".freeze, token: token, tag_end: TagEnd.inspect))
     end
 
-    def raise_missing_variable_terminator(token, options)
-      raise SyntaxError.new(options[:locale].t("errors.syntax.variable_termination".freeze, token: token, tag_end: VariableEnd.inspect))
+    def raise_missing_variable_terminator(token, parse_context)
+      raise SyntaxError.new(parse_context.locale.t("errors.syntax.variable_termination".freeze, token: token, tag_end: VariableEnd.inspect))
     end
 
     def registered_tags

lib/liquid/condition.rb

@@ -41,16 +41,22 @@ module Liquid
     end
 
     def evaluate(context = Context.new)
-      result = interpret_condition(left, right, operator, context)
+      condition = self
+      result = nil
+      loop do
+        result = interpret_condition(condition.left, condition.right, condition.operator, context)
 
-      case @child_relation
-      when :or
-        result || @child_condition.evaluate(context)
-      when :and
-        result && @child_condition.evaluate(context)
-      else
-        result
+        case condition.child_relation
+        when :or
+          break if result
+        when :and
+          break unless result
+        else
+          break
+        end
+        condition = condition.child_condition
       end
+      result
     end
 
     def or(condition)
@@ -75,6 +81,10 @@ module Liquid
       "#<Condition #{[@left, @operator, @right].compact.join(' '.freeze)}>"
     end
 
+    protected
+
+    attr_reader :child_relation, :child_condition
+
     private
 
     def equal_variables(left, right)
@@ -110,7 +120,7 @@ module Liquid
 
       if operation.respond_to?(:call)
         operation.call(self, left, right)
-      elsif left.respond_to?(operation) && right.respond_to?(operation)
+      elsif left.respond_to?(operation) && right.respond_to?(operation) && !left.is_a?(Hash) && !right.is_a?(Hash)
         begin
           left.send(operation, right)
         rescue ::ArgumentError => e

lib/liquid/context.rb

@@ -13,24 +13,32 @@ module Liquid
   #   context['bob']  #=> nil  class Context
   class Context
     attr_reader :scopes, :errors, :registers, :environments, :resource_limits
-    attr_accessor :exception_handler, :template_name
+    attr_accessor :exception_renderer, :template_name, :partial, :global_filter, :strict_variables, :strict_filters
 
     def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil)
       @environments     = [environments].flatten
       @scopes           = [(outer_scope || {})]
       @registers        = registers
       @errors           = []
+      @partial          = false
+      @strict_variables = false
       @resource_limits  = resource_limits || ResourceLimits.new(Template.default_resource_limits)
       squash_instance_assigns_with_environments
 
       @this_stack_used = false
 
+      self.exception_renderer = Template.default_exception_renderer
       if rethrow_errors
-        self.exception_handler = ->(e) { raise }
+        self.exception_renderer = ->(e) { raise }
       end
 
       @interrupts = []
       @filters = []
+      @global_filter = nil
+    end
+
+    def warnings
+      @warnings ||= []
     end
 
     def strainer
@@ -47,6 +55,10 @@ 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?
@@ -62,28 +74,12 @@ module Liquid
       @interrupts.pop
     end
 
-    def handle_error(e, token = nil)
-      if e.is_a?(Liquid::Error)
-        e.template_name = template_name
-        e.set_line_number_from_token(token)
-      end
-
-      output = nil
-
-      if exception_handler
-        result = exception_handler.call(e)
-        case result
-        when Exception
-          e = result
-          e.set_line_number_from_token(token) if e.is_a?(Liquid::Error)
-        when String
-          output = result
-        else
-          raise if result
-        end
-      end
+    def handle_error(e, line_number = nil)
+      e = internal_error unless e.is_a?(Liquid::Error)
+      e.template_name ||= template_name
+      e.line_number ||= line_number
       errors.push(e)
-      output || Liquid::Error.render(e)
+      exception_renderer.call(e).to_s
     end
 
     def invoke(method, *args)
@@ -93,7 +89,7 @@ module Liquid
     # Push new local scope on the stack. use <tt>Context#stack</tt> instead
     def push(new_scope = {})
       @scopes.unshift(new_scope)
-      raise StackLevelError, "Nesting too deep".freeze if @scopes.length > 100
+      raise StackLevelError, "Nesting too deep".freeze if @scopes.length > Block::MAX_DEPTH
     end
 
     # Merge a hash of variables in the current local scope
@@ -164,7 +160,7 @@ module Liquid
     end
 
     # Fetches an object starting at the local scope and then moving up the hierachy
-    def find_variable(key)
+    def find_variable(key, raise_on_not_found: true)
       # This was changed from find() to find_index() because this is a very hot
       # path and find_index() is optimized in MRI to reduce object allocation
       index = @scopes.find_index { |s| s.key?(key) }
@@ -174,8 +170,10 @@ module Liquid
 
       if scope.nil?
         @environments.each do |e|
-          variable = lookup_and_evaluate(e, key)
-          unless variable.nil?
+          variable = lookup_and_evaluate(e, key, raise_on_not_found: raise_on_not_found)
+          # When lookup returned a value OR there is no value but the lookup also did not raise
+          # then it is the value we are looking for.
+          if !variable.nil? || @strict_variables && raise_on_not_found
             scope = e
             break
           end
@@ -183,7 +181,7 @@ module Liquid
       end
 
       scope ||= @environments.last || @scopes.last
-      variable ||= lookup_and_evaluate(scope, key)
+      variable ||= lookup_and_evaluate(scope, key, raise_on_not_found: raise_on_not_found)
 
       variable = variable.to_liquid
       variable.context = self if variable.respond_to?(:context=)
@@ -191,8 +189,14 @@ module Liquid
       variable
     end
 
-    def lookup_and_evaluate(obj, key)
-      if (value = obj[key]).is_a?(Proc) && obj.respond_to?(:[]=)
+    def lookup_and_evaluate(obj, key, raise_on_not_found: true)
+      if @strict_variables && raise_on_not_found && 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
@@ -201,6 +205,13 @@ module Liquid
 
     private
 
+    def internal_error
+      # raise and catch to set backtrace and cause on exception
+      raise Liquid::InternalError, 'internal'
+    rescue Liquid::InternalError => exc
+      exc
+    end
+
     def squash_instance_assigns_with_environments
       @scopes.last.each_key do |k|
         @environments.each do |env|

lib/liquid/document.rb

@@ -1,27 +1,26 @@
 module Liquid
   class Document < BlockBody
-    DEFAULT_OPTIONS = {
-      locale: I18n.new
-    }
-
-    def self.parse(tokens, options)
+    def self.parse(tokens, parse_context)
       doc = new
-      doc.parse(tokens, DEFAULT_OPTIONS.merge(options))
+      doc.parse(tokens, parse_context)
       doc
     end
 
-    def parse(tokens, options)
+    def parse(tokens, parse_context)
       super do |end_tag_name, end_tag_params|
-        unknown_tag(end_tag_name, options) if end_tag_name
+        unknown_tag(end_tag_name, parse_context) if end_tag_name
       end
+    rescue SyntaxError => e
+      e.line_number ||= parse_context.line_number
+      raise
     end
 
-    def unknown_tag(tag, options)
+    def unknown_tag(tag, parse_context)
       case tag
       when 'else'.freeze, 'end'.freeze
-        raise SyntaxError.new(options[:locale].t("errors.syntax.unexpected_outer_tag".freeze, tag: tag))
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unexpected_outer_tag".freeze, tag: tag))
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.unknown_tag".freeze, tag: tag))
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unknown_tag".freeze, tag: tag))
       end
     end
   end

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

@@ -17,20 +17,6 @@ module Liquid
       str
     end
 
-    def set_line_number_from_token(token)
-      return unless token.respond_to?(:line_number)
-      return if line_number
-      self.line_number = token.line_number
-    end
-
-    def self.render(e)
-      if e.is_a?(Liquid::Error)
-        e.to_s
-      else
-        "Liquid error: #{e}"
-      end
-    end
-
     private
 
     def message_prefix
@@ -62,4 +48,9 @@ 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)
+  InternalError = Class.new(Error)
 end

lib/liquid/extensions.rb

@@ -7,44 +7,56 @@ class String # :nodoc:
   end
 end
 
-class Array  # :nodoc:
+class Symbol # :nodoc:
+  def to_liquid
+    to_s
+  end
+end
+
+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

@@ -8,8 +8,8 @@ module Liquid
   #
   # Example:
   #
-  # Liquid::Template.file_system = Liquid::LocalFileSystem.new(template_path)
-  # liquid = Liquid::Template.parse(template)
+  #   Liquid::Template.file_system = Liquid::LocalFileSystem.new(template_path)
+  #   liquid = Liquid::Template.parse(template)
   #
   # This will parse the template with a LocalFileSystem implementation rooted at 'template_path'.
   class BlankFileSystem
@@ -26,10 +26,10 @@ module Liquid
   #
   # Example:
   #
-  # file_system = Liquid::LocalFileSystem.new("/some/path")
+  #   file_system = Liquid::LocalFileSystem.new("/some/path")
   #
-  # file_system.full_path("mypartial")       # => "/some/path/_mypartial.liquid"
-  # file_system.full_path("dir/mypartial")   # => "/some/path/dir/_mypartial.liquid"
+  #   file_system.full_path("mypartial")       # => "/some/path/_mypartial.liquid"
+  #   file_system.full_path("dir/mypartial")   # => "/some/path/dir/_mypartial.liquid"
   #
   # Optionally in the second argument you can specify a custom pattern for template filenames.
   # The Kernel::sprintf format specification is used.
@@ -37,9 +37,9 @@ module Liquid
   #
   # Example:
   #
-  # file_system = Liquid::LocalFileSystem.new("/some/path", "%s.html")
+  #   file_system = Liquid::LocalFileSystem.new("/some/path", "%s.html")
   #
-  # file_system.full_path("index") # => "/some/path/index.html"
+  #   file_system.full_path("index") # => "/some/path/index.html"
   #
   class LocalFileSystem
     attr_accessor :root
@@ -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/lexer.rb

@@ -18,10 +18,10 @@ module Liquid
     DOUBLE_STRING_LITERAL = /"[^\"]*"/
     NUMBER_LITERAL = /-?\d+(\.\d+)?/
     DOTDOT = /\.\./
-    COMPARISON_OPERATOR = /==|!=|<>|<=?|>=?|contains/
+    COMPARISON_OPERATOR = /==|!=|<>|<=?|>=?|contains(?=\s)/
 
     def initialize(input)
-      @ss = StringScanner.new(input.rstrip)
+      @ss = StringScanner.new(input)
     end
 
     def tokenize
@@ -29,6 +29,7 @@ module Liquid
 
       until @ss.eos?
         @ss.skip(/\s*/)
+        break if @ss.eos?
         tok = case
         when t = @ss.scan(COMPARISON_OPERATOR) then [:comparison, t]
         when t = @ss.scan(SINGLE_STRING_LITERAL) then [:string, t]

lib/liquid/locales/en.yml

@@ -22,3 +22,5 @@
       tag_never_closed: "'%{block_name}' tag was never closed"
       meta_syntax_error: "Liquid syntax error: #{e.message}"
       table_row: "Syntax Error in 'table_row loop' - Valid syntax: table_row [item] in [collection] cols=3"
+    argument:
+      include: "Argument error in tag 'include' - Illegal template name"

lib/liquid/parse_context.rb

@@ -0,0 +1,38 @@
+module Liquid
+  class ParseContext
+    attr_accessor :locale, :line_number, :trim_whitespace, :depth
+    attr_reader :partial, :warnings, :error_mode
+
+    def initialize(options = {})
+      @template_options = options ? options.dup : {}
+      @locale = @template_options[:locale] ||= I18n.new
+      @warnings = []
+      self.depth = 0
+      self.partial = false
+    end
+
+    def [](option_key)
+      @options[option_key]
+    end
+
+    def partial=(value)
+      @partial = value
+      @options = value ? partial_options : @template_options
+      @error_mode = @options[:error_mode] || Template.error_mode
+      value
+    end
+
+    def partial_options
+      @partial_options ||= begin
+        dont_pass = @template_options[:include_options_blacklist]
+        if dont_pass == true
+          { locale: locale }
+        elsif dont_pass.is_a?(Array)
+          @template_options.reject { |k, v| dont_pass.include?(k) }
+        else
+          @template_options
+        end
+      end
+    end
+  end
+end

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/parser_switching.rb

@@ -1,16 +1,14 @@
 module Liquid
   module ParserSwitching
     def parse_with_selected_parser(markup)
-      case @options[:error_mode] || Template.error_mode
+      case parse_context.error_mode
       when :strict then strict_parse_with_error_context(markup)
       when :lax    then lax_parse(markup)
       when :warn
         begin
           return strict_parse_with_error_context(markup)
         rescue SyntaxError => e
-          e.set_line_number_from_token(markup)
-          @warnings ||= []
-          @warnings << e
+          parse_context.warnings << e
           return lax_parse(markup)
         end
       end
@@ -21,6 +19,7 @@ module Liquid
     def strict_parse_with_error_context(markup)
       strict_parse(markup)
     rescue SyntaxError => e
+      e.line_number = line_number
       e.markup_context = markup_context(markup)
       raise e
     end

lib/liquid/profiler.rb

@@ -19,7 +19,7 @@ module Liquid
   # inside of <tt>{% include %}</tt> tags.
   #
   #   profile.each do |node|
-  #     # Access to the token itself
+  #     # Access to the node itself
   #     node.code
   #
   #     # Which template and line number of this node.
@@ -46,15 +46,15 @@ module Liquid
     class Timing
       attr_reader :code, :partial, :line_number, :children
 
-      def initialize(token, partial)
-        @code        = token.respond_to?(:raw) ? token.raw : token
+      def initialize(node, partial)
+        @code        = node.respond_to?(:raw) ? node.raw : node
         @partial     = partial
-        @line_number = token.respond_to?(:line_number) ? token.line_number : nil
+        @line_number = node.respond_to?(:line_number) ? node.line_number : nil
         @children    = []
       end
 
-      def self.start(token, partial)
-        new(token, partial).tap(&:start)
+      def self.start(node, partial)
+        new(node, partial).tap(&:start)
       end
 
       def start
@@ -70,11 +70,11 @@ module Liquid
       end
     end
 
-    def self.profile_token_render(token)
-      if Profiler.current_profile && token.respond_to?(:render)
-        Profiler.current_profile.start_token(token)
+    def self.profile_node_render(node)
+      if Profiler.current_profile && node.respond_to?(:render)
+        Profiler.current_profile.start_node(node)
         output = yield
-        Profiler.current_profile.end_token(token)
+        Profiler.current_profile.end_node(node)
         output
       else
         yield
@@ -132,11 +132,11 @@ module Liquid
       @root_timing.children.length
     end
 
-    def start_token(token)
-      @timing_stack.push(Timing.start(token, current_partial))
+    def start_node(node)
+      @timing_stack.push(Timing.start(node, current_partial))
     end
 
-    def end_token(_token)
+    def end_node(_node)
       timing = @timing_stack.pop
       timing.finish
 

lib/liquid/profiler/hooks.rb

@@ -1,13 +1,13 @@
 module Liquid
   class BlockBody
-    def render_token_with_profiling(token, context)
-      Profiler.profile_token_render(token) do
-        render_token_without_profiling(token, context)
+    def render_node_with_profiling(node, context)
+      Profiler.profile_node_render(node) do
+        render_node_without_profiling(node, context)
       end
     end
 
-    alias_method :render_token_without_profiling, :render_token
-    alias_method :render_token, :render_token_with_profiling
+    alias_method :render_node_without_profiling, :render_node
+    alias_method :render_node, :render_node_with_profiling
   end
 
   class Include < Tag

lib/liquid/range_lookup.rb

@@ -16,7 +16,22 @@ module Liquid
     end
 
     def evaluate(context)
-      context.evaluate(@start_obj).to_i..context.evaluate(@end_obj).to_i
+      start_int = to_integer(context.evaluate(@start_obj))
+      end_int = to_integer(context.evaluate(@end_obj))
+      start_int..end_int
+    end
+
+    private
+
+    def to_integer(input)
+      case input
+      when Integer
+        input
+      when NilClass, String
+        input.to_i
+      else
+        Utils.to_integer(input)
+      end
     end
   end
 end

lib/liquid/standardfilters.rb

@@ -33,7 +33,7 @@ module Liquid
     end
 
     def escape(input)
-      CGI.escapeHTML(input).untaint rescue input
+      CGI.escapeHTML(input.to_s).untaint unless input.nil?
     end
     alias_method :h, :escape
 
@@ -42,12 +42,16 @@ module Liquid
     end
 
     def url_encode(input)
-      CGI.escape(input) rescue input
+      CGI.escape(input.to_s) unless input.nil?
+    end
+
+    def url_decode(input)
+      CGI.unescape(input.to_s) unless input.nil?
     end
 
     def slice(input, offset, length = nil)
-      offset = to_integer(offset)
-      length = length ? to_integer(length) : 1
+      offset = Utils.to_integer(offset)
+      length = length ? Utils.to_integer(length) : 1
 
       if input.is_a?(Array)
         input.slice(offset, length) || []
@@ -59,19 +63,21 @@ module Liquid
     # Truncate a string down to x characters
     def truncate(input, length = 50, truncate_string = "...".freeze)
       return if input.nil?
-      length = to_integer(length)
-      l = length - truncate_string.length
+      input_str = input.to_s
+      length = Utils.to_integer(length)
+      truncate_string_str = truncate_string.to_s
+      l = length - truncate_string_str.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_str : input_str
     end
 
     def truncatewords(input, words = 15, truncate_string = "...".freeze)
       return if input.nil?
       wordlist = input.to_s.split
-      words = to_integer(words)
+      words = Utils.to_integer(words)
       l = words - 1
       l = 0 if l < 0
-      wordlist.length > l ? wordlist[0..l].join(" ".freeze) + truncate_string : input
+      wordlist.length > l ? wordlist[0..l].join(" ".freeze) + truncate_string.to_s : input
     end
 
     # Split input string into an array of substrings separated by given pattern.
@@ -80,7 +86,7 @@ module Liquid
     #   <div class="summary">{{ post | split '//' | first }}</div>
     #
     def split(input, pattern)
-      input.to_s.split(pattern)
+      input.to_s.split(pattern.to_s)
     end
 
     def strip(input)
@@ -105,11 +111,6 @@ module Liquid
       input.to_s.gsub(/\r?\n/, ''.freeze)
     end
 
-    # Remove whitespace between HTML tags
-    def strip_html_whitespace(input)
-      Spaceless.strip_html_whitespace(input.to_s)
-    end
-
     # Join elements of the array with certain character between them
     def join(input, glue = ' '.freeze)
       InputIterator.new(input).join(glue)
@@ -121,10 +122,18 @@ 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) }
+        ary.sort do |a, b|
+          a = a[property]
+          b = b[property]
+          if a && b
+            a <=> b
+          else
+            a ? -1 : 1
+          end
+        end
       end
     end
 
@@ -135,10 +144,10 @@ 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
 
@@ -149,6 +158,8 @@ 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
@@ -168,7 +179,8 @@ 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
@@ -180,21 +192,23 @@ 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
 
     # Replace occurrences of a string with another
     def replace(input, string, replacement = ''.freeze)
-      input.to_s.gsub(string.to_s, replacement.to_s)
+      replacement = replacement.to_s
+      input.to_s.gsub(string.to_s) { replacement }
     end
 
     # Replace the first occurrences of a string with another
     def replace_first(input, string, replacement = ''.freeze)
-      input.to_s.sub(string.to_s, replacement.to_s)
+      replacement = replacement.to_s
+      input.to_s.sub(string.to_s) { replacement }
     end
 
     # remove a substring
@@ -213,6 +227,9 @@ 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
 
@@ -260,7 +277,7 @@ module Liquid
     def date(input, format)
       return input if format.to_s.empty?
 
-      return input unless date = to_date(input)
+      return input unless date = Utils.to_date(input)
 
       date.strftime(format.to_s)
     end
@@ -283,6 +300,12 @@ 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, :+)
@@ -312,7 +335,7 @@ module Liquid
     end
 
     def round(input, n = 0)
-      result = to_number(input).round(to_number(n))
+      result = Utils.to_number(input).round(Utils.to_number(n))
       result = result.to_f if result.is_a?(BigDecimal)
       result = result.to_i if n == 0
       result
@@ -321,69 +344,29 @@ module Liquid
     end
 
     def ceil(input)
-      to_number(input).ceil.to_i
+      Utils.to_number(input).ceil.to_i
     rescue ::FloatDomainError => e
       raise Liquid::FloatDomainError, e.message
     end
 
     def floor(input)
-      to_number(input).floor.to_i
+      Utils.to_number(input).floor.to_i
     rescue ::FloatDomainError => e
       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
 
-    def to_integer(num)
-      return num if num.is_a?(Integer)
-      num = num.to_s
-      begin
-        Integer(num)
-      rescue ::ArgumentError
-        raise Liquid::ArgumentError, "invalid integer"
-      end
-    end
-
-    def to_number(obj)
-      case obj
-      when Float
-        BigDecimal.new(obj.to_s)
-      when Numeric
-        obj
-      when String
-        (obj.strip =~ /\A\d+\.\d+\z/) ? BigDecimal.new(obj) : obj.to_i
-      else
-        0
-      end
-    end
-
-    def to_date(obj)
-      return obj if obj.respond_to?(:strftime)
-
-      if obj.is_a?(String)
-        return nil if obj.empty?
-        obj = obj.downcase
-      end
-
-      case obj
-      when 'now'.freeze, 'today'.freeze
-        Time.now
-      when /\A\d+\z/, Integer
-        Time.at(obj.to_i)
-      when String
-        Time.parse(obj)
-      end
-    rescue ArgumentError
-      nil
-    end
-
     def apply_operation(input, operand, operation)
-      result = to_number(input).send(operation, to_number(operand))
+      result = Utils.to_number(input).send(operation, Utils.to_number(operand))
       result.is_a?(BigDecimal) ? result.to_f : result
     end
 
@@ -403,11 +386,11 @@ module Liquid
       end
 
       def join(glue)
-        to_a.join(glue)
+        to_a.join(glue.to_s)
       end
 
       def concat(args)
-        to_a.concat args
+        to_a.concat(args)
       end
 
       def reverse
@@ -422,6 +405,11 @@ 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

@@ -26,14 +26,20 @@ module Liquid
     end
 
     def self.add_filter(filter)
-      raise ArgumentError, "Expected module but got: #{f.class}" unless filter.is_a?(Module)
-      unless self.class.include?(filter)
-        send(:include, filter)
-        @filter_methods.merge(filter.public_instance_methods.map(&:to_s))
+      raise ArgumentError, "Expected module but got: #{filter.class}" unless filter.is_a?(Module)
+      unless self.include?(filter)
+        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
 
     def self.global_filter(filter)
+      @@strainer_class_cache.clear
       @@global_strainer.add_filter(filter)
     end
 
@@ -48,11 +54,13 @@ 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/tag.rb

@@ -1,23 +1,24 @@
 module Liquid
   class Tag
-    attr_accessor :options, :line_number
-    attr_reader :nodelist, :warnings
+    attr_reader :nodelist, :tag_name, :line_number, :parse_context
+    alias_method :options, :parse_context
     include ParserSwitching
 
     class << self
-      def parse(tag_name, markup, tokens, options)
+      def parse(tag_name, markup, tokenizer, options)
         tag = new(tag_name, markup, options)
-        tag.parse(tokens)
+        tag.parse(tokenizer)
         tag
       end
 
       private :new
     end
 
-    def initialize(tag_name, markup, options)
+    def initialize(tag_name, markup, parse_context)
       @tag_name   = tag_name
       @markup     = markup
-      @options    = options
+      @parse_context = parse_context
+      @line_number = parse_context.line_number
     end
 
     def parse(_tokens)

lib/liquid/tags/assign.rb

@@ -15,7 +15,6 @@ module Liquid
       if markup =~ Syntax
         @to = $1
         @from = Variable.new($2, options)
-        @from.line_number = line_number
       else
         raise SyntaxError.new options[:locale].t("errors.syntax.assign".freeze)
       end
@@ -24,16 +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

@@ -30,14 +30,14 @@ module Liquid
     end
 
     def render(context)
-      context.registers[:cycle] ||= Hash.new(0)
+      context.registers[:cycle] ||= {}
 
       context.stack do
         key = context.evaluate(@name)
-        iteration = context.registers[:cycle][key]
+        iteration = context.registers[:cycle][key].to_i
         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

@@ -23,7 +23,7 @@ module Liquid
   #      {{ item.name }}
   #    {% end %}
   #
-  #  To reverse the for loop simply use {% for item in collection reversed %}
+  #  To reverse the for loop simply use {% for item in collection reversed %} (note that the flag's spelling is different to the filter `reverse`)
   #
   # == Available variables:
   #
@@ -46,10 +46,15 @@ module Liquid
   class For < Block
     Syntax = /\A(#{VariableSegment}+)\s+in\s+(#{QuotedFragment}+)\s*(reversed)?/o
 
+    attr_reader :collection_name
+    attr_reader :variable_name
+
     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 +72,13 @@ 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 +101,7 @@ 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 +119,63 @@ module Liquid
 
     private
 
+    def collection_segment(context)
+      offsets = context.registers[:for] ||= {}
+
+      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/if.rb

@@ -83,17 +83,20 @@ module Liquid
 
     def strict_parse(markup)
       p = Parser.new(markup)
-      condition = parse_binary_comparison(p)
+      condition = parse_binary_comparisons(p)
       p.consume(:end_of_string)
       condition
     end
 
-    def parse_binary_comparison(p)
+    def parse_binary_comparisons(p)
       condition = parse_comparison(p)
-      if op = (p.id?('and'.freeze) || p.id?('or'.freeze))
-        condition.send(op, parse_binary_comparison(p))
+      first_condition = condition
+      while op = (p.id?('and'.freeze) || p.id?('or'.freeze))
+        child_condition = parse_comparison(p)
+        condition.send(op, child_condition)
+        condition = child_condition
       end
-      condition
+      first_condition
     end
 
     def parse_comparison(p)

lib/liquid/tags/include.rb

@@ -42,19 +42,22 @@ module Liquid
 
     def render(context)
       template_name = context.evaluate(@template_name_expr)
-      partial = load_cached_partial(template_name, context)
+      raise ArgumentError.new(options[:locale].t("errors.argument.include")) unless template_name
 
+      partial = load_cached_partial(template_name, context)
       context_variable_name = template_name.split('/'.freeze).last
 
       variable = if @variable_name_expr
         context.evaluate(@variable_name_expr)
       else
-        context.find_variable(template_name)
+        context.find_variable(template_name, raise_on_not_found: false)
       end
 
       old_template_name = context.template_name
+      old_partial = context.partial
       begin
         context.template_name = template_name
+        context.partial = true
         context.stack do
           @attributes.each do |key, value|
             context[key] = context.evaluate(value)
@@ -72,11 +75,15 @@ module Liquid
         end
       ensure
         context.template_name = old_template_name
+        context.partial = old_partial
       end
     end
 
     private
 
+    alias_method :parse_context, :options
+    private :parse_context
+
     def load_cached_partial(template_name, context)
       cached_partials = context.registers[:cached_partials] || {}
 
@@ -84,7 +91,12 @@ module Liquid
         return cached
       end
       source = read_template_from_file_system(context)
-      partial = Liquid::Template.parse(source, pass_options)
+      begin
+        parse_context.partial = true
+        partial = Liquid::Template.parse(source, parse_context)
+      ensure
+        parse_context.partial = false
+      end
       cached_partials[template_name] = partial
       context.registers[:cached_partials] = cached_partials
       partial
@@ -95,16 +107,6 @@ module Liquid
 
       file_system.read_template_file(context.evaluate(@template_name_expr))
     end
-
-    def pass_options
-      dont_pass = @options[:include_options_blacklist]
-      return { locale: @options[:locale] } if dont_pass == true
-      opts = @options.merge(included: true, include_options_blacklist: false)
-      if dont_pass.is_a?(Array)
-        dont_pass.each { |o| opts.delete(o) }
-      end
-      opts
-    end
   end
 
   Template.register_tag('include'.freeze, Include)

lib/liquid/tags/raw.rb

@@ -3,12 +3,10 @@ module Liquid
     Syntax = /\A\s*\z/
     FullTokenPossiblyInvalid = /\A(.*)#{TagStart}\s*(\w+)\s*(.*)?#{TagEnd}\z/om
 
-    def initialize(tag_name, markup, options)
+    def initialize(tag_name, markup, parse_context)
       super
 
-      unless markup =~ Syntax
-        raise SyntaxError.new(@options[:locale].t("errors.syntax.tag_unexpected_args".freeze, tag: tag_name))
-      end
+      ensure_valid_markup(tag_name, markup, parse_context)
     end
 
     def parse(tokens)
@@ -21,7 +19,7 @@ module Liquid
         @body << token unless token.empty?
       end
 
-      raise SyntaxError.new(@options[:locale].t("errors.syntax.tag_never_closed".freeze, block_name: block_name))
+      raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_never_closed".freeze, block_name: block_name))
     end
 
     def render(_context)
@@ -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/spaceless.rb

@@ -1,24 +0,0 @@
-module Liquid
-  # The spaceless tag strips whitespace between HTML tags using a simple regex.
-  #
-  # == Usage:
-  #    {% spaceless %}
-  #      <h1>
-  #        Hello
-  #      </h1>
-  #    {% endspaceless %}
-  #
-  class Spaceless < Block
-    HTML_STRIP_SPACE_REGEXP = />\s+</
-
-    def render(context)
-      self.class.strip_html_whitespace(super)
-    end
-
-    def self.strip_html_whitespace(input)
-      input.gsub(HTML_STRIP_SPACE_REGEXP, '><')
-    end
-  end
-
-  Template.register_tag('spaceless'.freeze, Spaceless)
-end

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

@@ -14,13 +14,15 @@ module Liquid
   #
   class Template
     attr_accessor :root
-    attr_reader :resource_limits
+    attr_reader :resource_limits, :warnings
 
     @@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)
@@ -63,6 +69,11 @@ module Liquid
       # :error raises an error when tainted output is used
       attr_writer :taint_mode
 
+      attr_accessor :default_exception_renderer
+      Template.default_exception_renderer = lambda do |exception|
+        exception
+      end
+
       def file_system
         @@file_system
       end
@@ -80,11 +91,11 @@ 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 +118,7 @@ module Liquid
     end
 
     def initialize
+      @rethrow_errors = false
       @resource_limits = ResourceLimits.new(self.class.default_resource_limits)
     end
 
@@ -116,16 +128,12 @@ module Liquid
       @options = options
       @profiling = options[:profile]
       @line_numbers = options[:line_numbers] || @profiling
-      @root = Document.parse(tokenize(source), options)
-      @warnings = nil
+      parse_context = options.is_a?(ParseContext) ? options : ParseContext.new(options)
+      @root = Document.parse(tokenize(source), parse_context)
+      @warnings = parse_context.warnings
       self
     end
 
-    def warnings
-      return [] unless @root
-      @warnings ||= @root.warnings
-    end
-
     def registers
       @registers ||= {}
     end
@@ -164,7 +172,7 @@ module Liquid
         c = args.shift
 
         if @rethrow_errors
-          c.exception_handler = ->(e) { raise }
+          c.exception_renderer = ->(e) { raise }
         end
 
         c
@@ -183,20 +191,10 @@ 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
 
@@ -206,7 +204,7 @@ module Liquid
       begin
         # render the nodelist.
         # for performance reasons we get an array back here. join will make a string out of it.
-        result = with_profiling do
+        result = with_profiling(context) do
           @root.render(context)
         end
         result.respond_to?(:join) ? result.join : result
@@ -228,8 +226,8 @@ module Liquid
       Tokenizer.new(source, @line_numbers)
     end
 
-    def with_profiling
-      if @profiling && !@options[:included]
+    def with_profiling(context)
+      if @profiling && !context.partial
         raise "Profiler not loaded, require 'liquid/profiler' first" unless defined?(Liquid::Profiler)
 
         @profiler = Profiler.new
@@ -244,5 +242,13 @@ 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_renderer = options[:exception_renderer] if options[:exception_renderer]
+      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/token.rb

@@ -1,18 +0,0 @@
-module Liquid
-  class Token < String
-    attr_reader :line_number
-
-    def initialize(content, line_number)
-      super(content)
-      @line_number = line_number
-    end
-
-    def raw
-      "<raw>"
-    end
-
-    def child(string)
-      Token.new(string, @line_number)
-    end
-  end
-end

lib/liquid/tokenizer.rb

@@ -1,13 +1,17 @@
 module Liquid
   class Tokenizer
+    attr_reader :line_number
+
     def initialize(source, line_numbers = false)
       @source = source
-      @line_numbers = line_numbers
+      @line_number = line_numbers ? 1 : nil
       @tokens = tokenize
     end
 
     def shift
-      @tokens.shift
+      token = @tokens.shift
+      @line_number += token.count("\n") if @line_number && token
+      token
     end
 
     private
@@ -17,21 +21,11 @@ module Liquid
       return [] if @source.to_s.empty?
 
       tokens = @source.split(TemplateParser)
-      tokens = @line_numbers ? calculate_line_numbers(tokens) : tokens
 
       # removes the rogue empty element at the beginning of the array
       tokens.shift if tokens[0] && tokens[0].empty?
 
       tokens
     end
-
-    def calculate_line_numbers(tokens)
-      current_line = 1
-      tokens.map do |token|
-        Token.new(token, current_line).tap do
-          current_line += token.count("\n")
-        end
-      end
-    end
   end
 end

lib/liquid/utils.rb

@@ -32,5 +32,52 @@ module Liquid
 
       segments
     end
+
+    def self.to_integer(num)
+      return num if num.is_a?(Integer)
+      num = num.to_s
+      begin
+        Integer(num)
+      rescue ::ArgumentError
+        raise Liquid::ArgumentError, "invalid integer"
+      end
+    end
+
+    def self.to_number(obj)
+      case obj
+      when Float
+        BigDecimal.new(obj.to_s)
+      when Numeric
+        obj
+      when String
+        (obj.strip =~ /\A-?\d+\.\d+\z/) ? BigDecimal.new(obj) : obj.to_i
+      else
+        if obj.respond_to?(:to_number)
+          obj.to_number
+        else
+          0
+        end
+      end
+    end
+
+    def self.to_date(obj)
+      return obj if obj.respond_to?(:strftime)
+
+      if obj.is_a?(String)
+        return nil if obj.empty?
+        obj = obj.downcase
+      end
+
+      case obj
+      when 'now'.freeze, 'today'.freeze
+        Time.now
+      when /\A\d+\z/, Integer
+        Time.at(obj.to_i)
+      when String
+        Time.parse(obj)
+      end
+    rescue ::ArgumentError
+      nil
+    end
   end
 end

lib/liquid/variable.rb

@@ -11,14 +11,16 @@ module Liquid
   #
   class Variable
     FilterParser = /(?:\s+|#{QuotedFragment}|#{ArgumentSeparator})+/o
-    attr_accessor :filters, :name, :warnings
-    attr_accessor :line_number
+    attr_accessor :filters, :name, :line_number
+    attr_reader :parse_context
+    alias_method :options, :parse_context
     include ParserSwitching
 
-    def initialize(markup, options = {})
+    def initialize(markup, parse_context)
       @markup  = markup
       @name    = nil
-      @options = options || {}
+      @parse_context = parse_context
+      @line_number = parse_context.line_number
 
       parse_with_selected_parser(markup)
     end
@@ -71,10 +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(obj) }
+      end
+
+      obj = context.apply_global_filter(obj)
+
+      taint_check(context, obj)
+
+      obj
     end
 
     private
@@ -106,17 +114,22 @@ module Liquid
       parsed_args
     end
 
-    def taint_check(obj)
-      if obj.tainted?
-        @markup =~ QuotedFragment
-        name = Regexp.last_match(0)
-        case Template.taint_mode
-        when :warn
-          @warnings ||= []
-          @warnings << "variable '#{name}' is tainted and was not escaped"
-        when :error
-          raise TaintedError, "Error - variable '#{name}' is tainted and was not escaped"
-        end
+    def taint_check(context, obj)
+      return unless obj.tainted?
+      return if Template.taint_mode == :lax
+
+      @markup =~ QuotedFragment
+      name = Regexp.last_match(0)
+
+      error = TaintedError.new("variable '#{name}' is tainted and was not escaped")
+      error.line_number = line_number
+      error.template_name = context.template_name
+
+      case Template.taint_mode
+      when :warn
+        context.warnings << error
+      when :error
+        raise error
       end
     end
   end

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"
 end

liquid.gemspec

@@ -15,15 +15,16 @@ Gem::Specification.new do |s|
   s.license     = "MIT"
   # s.description = "A secure, non-evaling end user template engine with aesthetic markup."
 
+  s.required_ruby_version     = ">= 2.1.0"
   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"
 
-  s.add_development_dependency 'rake'
+  s.add_development_dependency 'rake', '~> 11.3'
   s.add_development_dependency 'minitest'
 end

performance/benchmark.rb

@@ -5,7 +5,7 @@ Liquid::Template.error_mode = ARGV.first.to_sym if ARGV.first
 profiler = ThemeRunner.new
 
 Benchmark.ips do |x|
-  x.time = 60
+  x.time = 10
   x.warmup = 5
 
   puts
@@ -13,5 +13,6 @@ Benchmark.ips do |x|
   puts
 
   x.report("parse:") { profiler.compile }
-  x.report("parse & run:") { profiler.run }
+  x.report("render:") { profiler.render }
+  x.report("parse & render:") { profiler.run }
 end

performance/theme_runner.rb

@@ -21,53 +21,100 @@ class ThemeRunner
     end
   end
 
-  # Load all templates into memory, do this now so that
-  # we don't profile IO.
+  # Initialize a new liquid ThemeRunner instance
+  # Will load all templates into memory, do this now so that we don't profile IO.
   def initialize
     @tests = Dir[__dir__ + '/tests/**/*.liquid'].collect do |test|
       next if File.basename(test) == 'theme.liquid'
 
       theme_path = File.dirname(test) + '/theme.liquid'
-
-      [File.read(test), (File.file?(theme_path) ? File.read(theme_path) : nil), test]
+      {
+        liquid: File.read(test),
+        layout: (File.file?(theme_path) ? File.read(theme_path) : nil),
+        template_name: test
+      }
     end.compact
+
+    compile_all_tests
   end
 
+  # `compile` will test just the compilation portion of liquid without any templates
   def compile
-    # Dup assigns because will make some changes to them
-
-    @tests.each do |liquid, layout, template_name|
-      tmpl = Liquid::Template.new
-      tmpl.parse(liquid)
-      tmpl = Liquid::Template.new
-      tmpl.parse(layout)
+    @tests.each do |test_hash|
+      Liquid::Template.new.parse(test_hash[:liquid])
+      Liquid::Template.new.parse(test_hash[:layout])
     end
   end
 
+  # `run` is called to benchmark rendering and compiling at the same time
   def run
-    # Dup assigns because will make some changes to them
-    assigns = Database.tables.dup
-
-    @tests.each do |liquid, layout, template_name|
-      # Compute page_tempalte outside of profiler run, uninteresting to profiler
-      page_template = File.basename(template_name, File.extname(template_name))
+    each_test do |liquid, layout, assigns, page_template, template_name|
       compile_and_render(liquid, layout, assigns, page_template, template_name)
     end
   end
 
+  # `render` is called to benchmark just the render portion of liquid
+  def render
+    @compiled_tests.each do |test|
+      tmpl = test[:tmpl]
+      assigns = test[:assigns]
+      layout = test[:layout]
+
+      if layout
+        assigns['content_for_layout'] = tmpl.render!(assigns)
+        layout.render!(assigns)
+      else
+        tmpl.render!(assigns)
+      end
+    end
+  end
+
+  private
+
   def compile_and_render(template, layout, assigns, page_template, template_file)
+    compiled_test = compile_test(template, layout, assigns, page_template, template_file)
+    assigns['content_for_layout'] = compiled_test[:tmpl].render!(assigns)
+    compiled_test[:layout].render!(assigns) if layout
+  end
+
+  def compile_all_tests
+    @compiled_tests = []
+    each_test do |liquid, layout, assigns, page_template, template_name|
+      @compiled_tests << compile_test(liquid, layout, assigns, page_template, template_name)
+    end
+    @compiled_tests
+  end
+
+  def compile_test(template, layout, assigns, page_template, template_file)
+    tmpl = init_template(page_template, template_file)
+    parsed_template = tmpl.parse(template).dup
+
+    if layout
+      parsed_layout = tmpl.parse(layout)
+      { tmpl: parsed_template, assigns: assigns, layout: parsed_layout }
+    else
+      { tmpl: parsed_template, assigns: assigns }
+    end
+  end
+
+  # utility method with similar functionality needed in `compile_all_tests` and `run`
+  def each_test
+    # Dup assigns because will make some changes to them
+    assigns = Database.tables.dup
+
+    @tests.each do |test_hash|
+      # Compute page_template outside of profiler run, uninteresting to profiler
+      page_template = File.basename(test_hash[:template_name], File.extname(test_hash[:template_name]))
+      yield(test_hash[:liquid], test_hash[:layout], assigns, page_template, test_hash[:template_name])
+    end
+  end
+
+  # set up a new Liquid::Template object for use in `compile_and_render` and `compile_test`
+  def init_template(page_template, template_file)
     tmpl = Liquid::Template.new
     tmpl.assigns['page_title'] = 'Page title'
     tmpl.assigns['template'] = page_template
     tmpl.registers[:file_system] = ThemeRunner::FileSystem.new(File.dirname(template_file))
-
-    content_for_layout = tmpl.parse(template).render!(assigns)
-
-    if layout
-      assigns['content_for_layout'] = content_for_layout
-      tmpl.parse(layout).render!(assigns)
-    else
-      content_for_layout
-    end
+    tmpl
   end
 end

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
 
@@ -124,8 +124,10 @@ class DropsTest < Minitest::Test
   def test_rendering_warns_on_tainted_attr
     with_taint_mode(:warn) do
       tpl = Liquid::Template.parse('{{ product.user_input }}')
-      tpl.render!('product' => ProductDrop.new)
-      assert_match /tainted/, tpl.warnings.first
+      context = Context.new('product' => ProductDrop.new)
+      tpl.render!(context)
+      assert_equal [Liquid::TaintedError], context.warnings.map(&:class)
+      assert_equal "variable 'product.user_input' is tainted and was not escaped", context.warnings.first.to_s(false)
     end
   end
 
@@ -155,14 +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
@@ -229,7 +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 +94,23 @@ 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_with_line_numbers_adds_numbers_to_parser_errors_with_whitespace_trim
+    err = assert_raises(SyntaxError) do
+      Liquid::Template.parse(%q(
+          foobar
+
+          {%- "cat" | foobar -%}
+
+          bla
+        ),
+        line_numbers: true
+      )
+    end
+
+    assert_match(/Liquid syntax error \(line 4\)/, err.message)
   end
 
   def test_parsing_warn_with_line_numbers_adds_numbers_to_lexer_errors
@@ -186,22 +202,40 @@ class ErrorHandlingTest < Minitest::Test
     end
   end
 
-  def test_exception_handler_with_string_result
-    template = Liquid::Template.parse('This is an argument error: {{ errors.argument_error }}')
-    output = template.render({ 'errors' => ErrorDrop.new }, exception_handler: ->(e) { '' })
-    assert_equal 'This is an argument error: ', output
-    assert_equal [ArgumentError], template.errors.map(&:class)
-  end
-
-  class InternalError < Liquid::Error
-  end
-
-  def test_exception_handler_with_exception_result
+  def test_default_exception_renderer_with_internal_error
     template = Liquid::Template.parse('This is a runtime error: {{ errors.runtime_error }}', line_numbers: true)
-    handler = ->(e) { e.is_a?(Liquid::Error) ? e : InternalError.new('internal') }
-    output = template.render({ 'errors' => ErrorDrop.new }, exception_handler: handler)
+
+    output = template.render({ 'errors' => ErrorDrop.new })
+
     assert_equal 'This is a runtime error: Liquid error (line 1): internal', output
-    assert_equal [InternalError], template.errors.map(&:class)
+    assert_equal [Liquid::InternalError], template.errors.map(&:class)
+  end
+
+  def test_setting_default_exception_renderer
+    old_exception_renderer = Liquid::Template.default_exception_renderer
+    exceptions = []
+    Liquid::Template.default_exception_renderer = ->(e) { exceptions << e; '' }
+    template = Liquid::Template.parse('This is a runtime error: {{ errors.argument_error }}')
+
+    output = template.render({ 'errors' => ErrorDrop.new })
+
+    assert_equal 'This is a runtime error: ', output
+    assert_equal [Liquid::ArgumentError], template.errors.map(&:class)
+  ensure
+    Liquid::Template.default_exception_renderer = old_exception_renderer if old_exception_renderer
+  end
+
+  def test_exception_renderer_exposing_non_liquid_error
+    template = Liquid::Template.parse('This is a runtime error: {{ errors.runtime_error }}', line_numbers: true)
+    exceptions = []
+    handler = ->(e) { exceptions << e; e.cause }
+
+    output = template.render({ 'errors' => ErrorDrop.new }, exception_renderer: handler)
+
+    assert_equal 'This is a runtime error: runtime error', output
+    assert_equal [Liquid::InternalError], exceptions.map(&:class)
+    assert_equal exceptions, template.errors
+    assert_equal '#<RuntimeError: runtime error>', exceptions.first.cause.inspect
   end
 
   class TestFileSystem

test/integration/filter_test.rb

@@ -39,13 +39,13 @@ class FiltersTest < Minitest::Test
     @context['var'] = 1000
     @context.add_filters(MoneyFilter)
 
-    assert_equal ' 1000$ ', Variable.new("var | money").render(@context)
+    assert_equal ' 1000$ ', Template.parse("{{var | money}}").render(@context)
   end
 
   def test_underscore_in_filter_name
     @context['var'] = 1000
     @context.add_filters(MoneyFilter)
-    assert_equal ' 1000$ ', Variable.new("var | money_with_underscore").render(@context)
+    assert_equal ' 1000$ ', Template.parse("{{var | money_with_underscore}}").render(@context)
   end
 
   def test_second_filter_overwrites_first
@@ -53,20 +53,20 @@ class FiltersTest < Minitest::Test
     @context.add_filters(MoneyFilter)
     @context.add_filters(CanadianMoneyFilter)
 
-    assert_equal ' 1000$ CAD ', Variable.new("var | money").render(@context)
+    assert_equal ' 1000$ CAD ', Template.parse("{{var | money}}").render(@context)
   end
 
   def test_size
     @context['var'] = 'abcd'
     @context.add_filters(MoneyFilter)
 
-    assert_equal 4, Variable.new("var | size").render(@context)
+    assert_equal '4', Template.parse("{{var | size}}").render(@context)
   end
 
   def test_join
     @context['var'] = [1, 2, 3, 4]
 
-    assert_equal "1 2 3 4", Variable.new("var | join").render(@context)
+    assert_equal "1 2 3 4", Template.parse("{{var | join}}").render(@context)
   end
 
   def test_sort
@@ -76,11 +76,11 @@ class FiltersTest < Minitest::Test
     @context['arrays'] = ['flower', 'are']
     @context['case_sensitive'] = ['sensitive', 'Expected', 'case']
 
-    assert_equal [1, 2, 3, 4], Variable.new("numbers | sort").render(@context)
-    assert_equal ['alphabetic', 'as', 'expected'], Variable.new("words | sort").render(@context)
-    assert_equal [3], Variable.new("value | sort").render(@context)
-    assert_equal ['are', 'flower'], Variable.new("arrays | sort").render(@context)
-    assert_equal ['Expected', 'case', 'sensitive'], Variable.new("case_sensitive | sort").render(@context)
+    assert_equal '1 2 3 4', Template.parse("{{numbers | sort | join}}").render(@context)
+    assert_equal 'alphabetic as expected', Template.parse("{{words | sort | join}}").render(@context)
+    assert_equal '3', Template.parse("{{value | sort}}").render(@context)
+    assert_equal 'are flower', Template.parse("{{arrays | sort | join}}").render(@context)
+    assert_equal 'Expected case sensitive', Template.parse("{{case_sensitive | sort | join}}").render(@context)
   end
 
   def test_sort_natural
@@ -89,19 +89,13 @@ class FiltersTest < Minitest::Test
     @context['objects'] = [TestObject.new('A'), TestObject.new('b'), TestObject.new('C')]
 
     # Test strings
-    assert_equal ['Assert', 'case', 'Insensitive'], Variable.new("words | sort_natural").render(@context)
+    assert_equal 'Assert case Insensitive', Template.parse("{{words | sort_natural | join}}").render(@context)
 
     # Test hashes
-    sorted = Variable.new("hashes | sort_natural: 'a'").render(@context)
-    assert_equal sorted[0]['a'], 'A'
-    assert_equal sorted[1]['a'], 'b'
-    assert_equal sorted[2]['a'], 'C'
+    assert_equal 'A b C', Template.parse("{{hashes | sort_natural: 'a' | map: 'a' | join}}").render(@context)
 
     # Test objects
-    sorted = Variable.new("objects | sort_natural: 'a'").render(@context)
-    assert_equal sorted[0].a, 'A'
-    assert_equal sorted[1].a, 'b'
-    assert_equal sorted[2].a, 'C'
+    assert_equal 'A b C', Template.parse("{{objects | sort_natural: 'a' | map: 'a' | join}}").render(@context)
   end
 
   def test_compact
@@ -110,49 +104,44 @@ class FiltersTest < Minitest::Test
     @context['objects'] = [TestObject.new('A'), TestObject.new(nil), TestObject.new('C')]
 
     # Test strings
-    assert_equal ['a', 'b', 'c'], Variable.new("words | compact").render(@context)
+    assert_equal 'a b c', Template.parse("{{words | compact | join}}").render(@context)
 
     # Test hashes
-    sorted = Variable.new("hashes | compact: 'a'").render(@context)
-    assert_equal sorted[0]['a'], 'A'
-    assert_equal sorted[1]['a'], 'C'
-    assert_nil sorted[2]
+    assert_equal 'A C', Template.parse("{{hashes | compact: 'a' | map: 'a' | join}}").render(@context)
 
     # Test objects
-    sorted = Variable.new("objects | compact: 'a'").render(@context)
-    assert_equal sorted[0].a, 'A'
-    assert_equal sorted[1].a, 'C'
-    assert_nil sorted[2]
+    assert_equal 'A C', Template.parse("{{objects | compact: 'a' | map: 'a' | join}}").render(@context)
   end
 
   def test_strip_html
     @context['var'] = "<b>bla blub</a>"
 
-    assert_equal "bla blub", Variable.new("var | strip_html").render(@context)
+    assert_equal "bla blub", Template.parse("{{ var | strip_html }}").render(@context)
   end
 
   def test_strip_html_ignore_comments_with_html
     @context['var'] = "<!-- split and some <ul> tag --><b>bla blub</a>"
 
-    assert_equal "bla blub", Variable.new("var | strip_html").render(@context)
+    assert_equal "bla blub", Template.parse("{{ var | strip_html }}").render(@context)
   end
 
   def test_capitalize
     @context['var'] = "blub"
 
-    assert_equal "Blub", Variable.new("var | capitalize").render(@context)
+    assert_equal "Blub", Template.parse("{{ var | capitalize }}").render(@context)
   end
 
   def test_nonexistent_filter_is_ignored
     @context['var'] = 1000
 
-    assert_equal 1000, Variable.new("var | xyzzy").render(@context)
+    assert_equal '1000', Template.parse("{{ var | xyzzy }}").render(@context)
   end
 
   def test_filter_with_keyword_arguments
     @context['surname'] = 'john'
+    @context['input'] = 'hello %{first_name}, %{last_name}'
     @context.add_filters(SubstituteFilter)
-    output = Variable.new(%( 'hello %{first_name}, %{last_name}' | substitute: first_name: surname, last_name: 'doe' )).render(@context)
+    output = Template.parse(%({{ input | substitute: first_name: surname, last_name: 'doe' }})).render(@context)
     assert_equal 'hello john, doe', output
   end
 
@@ -181,7 +170,7 @@ class FiltersInTemplate < Minitest::Test
   end
 end # FiltersTest
 
-class TestObject
+class TestObject < Liquid::Drop
   attr_accessor :a
   def initialize(a)
     @a = a

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/parsing_quirks_test.rb

@@ -115,4 +115,8 @@ class ParsingQuirksTest < Minitest::Test
       assert_template_result('12345', "{% for i in (1...5) %}{{ i }}{% endfor %}")
     end
   end
+
+  def test_contains_in_id
+    assert_template_result(' YES ', '{% if containsallshipments == true %} YES {% endif %}', 'containsallshipments' => true)
+  end
 end # ParsingQuirksTest

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 )
@@ -59,4 +63,18 @@ class SecurityTest < Minitest::Test
 
     assert_equal [], (Symbol.all_symbols - current_symbols)
   end
+
+  def test_max_depth_nested_blocks_does_not_raise_exception
+    depth = Liquid::Block::MAX_DEPTH
+    code = "{% if true %}" * depth + "rendered" + "{% endif %}" * depth
+    assert_equal "rendered", Template.parse(code).render!
+  end
+
+  def test_more_than_max_depth_nested_blocks_raises_exception
+    depth = Liquid::Block::MAX_DEPTH + 1
+    code = "{% if true %}" * depth + "rendered" + "{% endif %}" * depth
+    assert_raises(Liquid::StackLevelError) do
+      Template.parse(code).render!
+    end
+  end
 end # SecurityTest

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
 
@@ -105,20 +115,29 @@ class StandardFiltersTest < Minitest::Test
     assert_equal '...', @filters.truncate('1234567890', 0)
     assert_equal '1234567890', @filters.truncate('1234567890')
     assert_equal "测试...", @filters.truncate("测试测试测试测试", 5)
+    assert_equal '12341', @filters.truncate("1234567890", 5, 1)
   end
 
   def test_split
     assert_equal ['12', '34'], @filters.split('12~34', '~')
     assert_equal ['A? ', ' ,Z'], @filters.split('A? ~ ~ ~ ,Z', '~ ~ ~')
     assert_equal ['A?Z'], @filters.split('A?Z', '~')
-    # Regexp works although Liquid does not support.
-    assert_equal ['A', 'Z'], @filters.split('AxZ', /x/)
     assert_equal [], @filters.split(nil, ' ')
+    assert_equal ['A', 'Z'], @filters.split('A1Z', 1)
   end
 
   def test_escape
     assert_equal '&lt;strong&gt;', @filters.escape('<strong>')
+    assert_equal '1', @filters.escape(1)
+    assert_equal '2001-02-03', @filters.escape(Date.new(2001, 2, 3))
+    assert_nil @filters.escape(nil)
+  end
+
+  def test_h
     assert_equal '&lt;strong&gt;', @filters.h('<strong>')
+    assert_equal '1', @filters.h(1)
+    assert_equal '2001-02-03', @filters.h(Date.new(2001, 2, 3))
+    assert_nil @filters.h(nil)
   end
 
   def test_escape_once
@@ -127,7 +146,18 @@ class StandardFiltersTest < Minitest::Test
 
   def test_url_encode
     assert_equal 'foo%2B1%40example.com', @filters.url_encode('foo+1@example.com')
-    assert_equal nil, @filters.url_encode(nil)
+    assert_equal '1', @filters.url_encode(1)
+    assert_equal '2001-02-03', @filters.url_encode(Date.new(2001, 2, 3))
+    assert_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 '1', @filters.url_decode(1)
+    assert_equal '2001-02-03', @filters.url_decode(Date.new(2001, 2, 3))
+    assert_nil @filters.url_decode(nil)
   end
 
   def test_truncatewords
@@ -136,6 +166,7 @@ class StandardFiltersTest < Minitest::Test
     assert_equal 'one two three', @filters.truncatewords('one two three')
     assert_equal 'Two small (13&#8221; x 5.5&#8221; x 10&#8221; high) baskets fit inside one large basket (13&#8221;...', @filters.truncatewords('Two small (13&#8221; x 5.5&#8221; x 10&#8221; high) baskets fit inside one large basket (13&#8221; x 16&#8221; x 10.5&#8221; high) with cover.', 15)
     assert_equal "测试测试测试测试", @filters.truncatewords('测试测试测试测试', 5)
+    assert_equal 'one two1', @filters.truncatewords("one two three", 2, 1)
   end
 
   def test_strip_html
@@ -151,6 +182,7 @@ class StandardFiltersTest < Minitest::Test
   def test_join
     assert_equal '1 2 3 4', @filters.join([1, 2, 3, 4])
     assert_equal '1 - 2 - 3 - 4', @filters.join([1, 2, 3, 4], ' - ')
+    assert_equal '1121314', @filters.join([1, 2, 3, 4], 1)
   end
 
   def test_sort
@@ -158,6 +190,32 @@ 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_when_property_is_sometimes_missing_puts_nils_last
+    input = [
+      { "price" => 4, "handle" => "alpha" },
+      { "handle" => "beta" },
+      { "price" => 1, "handle" => "gamma" },
+      { "handle" => "delta" },
+      { "price" => 2, "handle" => "epsilon" }
+    ]
+    expectation = [
+      { "price" => 1, "handle" => "gamma" },
+      { "price" => 2, "handle" => "epsilon" },
+      { "price" => 4, "handle" => "alpha" },
+      { "handle" => "delta" },
+      { "handle" => "beta" }
+    ]
+    assert_equal expectation, @filters.sort(input, "price")
+  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 +235,14 @@ 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 +291,19 @@ 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 +317,10 @@ 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")
@@ -259,26 +342,30 @@ class StandardFiltersTest < Minitest::Test
     assert_equal "#{Date.today.year}", @filters.date('today', '%Y')
     assert_equal "#{Date.today.year}", @filters.date('Today', '%Y')
 
-    assert_equal nil, @filters.date(nil, "%B")
+    assert_nil @filters.date(nil, "%B")
 
     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
     assert_equal 1, @filters.first([1, 2, 3])
     assert_equal 3, @filters.last([1, 2, 3])
-    assert_equal nil, @filters.first([])
-    assert_equal nil, @filters.last([])
+    assert_nil @filters.first([])
+    assert_nil @filters.last([])
   end
 
   def test_replace
     assert_equal '2 2 2 2', @filters.replace('1 1 1 1', '1', 2)
     assert_equal '2 2 2 2', @filters.replace('1 1 1 1', 1, 2)
+    assert_equal "\\& \\& \\& \\&", @filters.replace('1 1 1 1', '1', "\\&")
     assert_equal '2 1 1 1', @filters.replace_first('1 1 1 1', '1', 2)
     assert_equal '2 1 1 1', @filters.replace_first('1 1 1 1', 1, 2)
+    assert_equal '\\& 1 1 1', @filters.replace_first("1 1 1 1", '1', "\\&")
     assert_template_result '2 1 1 1', "{{ '1 1 1 1' | replace_first: '1', 2 }}"
   end
 
@@ -321,20 +408,38 @@ 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 +453,8 @@ 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 +462,8 @@ 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 +473,9 @@ 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 +484,8 @@ 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 +494,8 @@ 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 +509,7 @@ 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
@@ -418,8 +533,18 @@ class StandardFiltersTest < Minitest::Test
     assert_template_result('a', "{{ 'a' | to_number }}")
   end
 
-  def test_strip_html_whitespace
-    html = "<a>\n\n   <b>  \n  <c>a</c> \r\n   </b>   </a>"
-    assert_template_result('<a><b><c>a</c></b></a>', "{{ a | strip_html_whitespace }}", { 'a' => html })
+  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/for_tag_test.rb

@@ -38,6 +38,12 @@ HERE
 
   def test_for_with_range
     assert_template_result(' 1  2  3 ', '{%for item in (1..3) %} {{item}} {%endfor%}')
+
+    assert_raises(Liquid::ArgumentError) do
+      Template.parse('{% for i in (a..2) %}{% endfor %}').render!("a" => [1, 2])
+    end
+
+    assert_template_result(' 0  1  2  3 ', '{% for item in (a..3) %} {{item}} {% endfor %}', "a" => "invalid integer")
   end
 
   def test_for_with_variable_range

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/include_tag_test.rb

@@ -137,7 +137,7 @@ class IncludeTagTest < Minitest::Test
 
     Liquid::Template.file_system = infinite_file_system.new
 
-    assert_raises(Liquid::StackLevelError, SystemStackError) do
+    assert_raises(Liquid::StackLevelError) do
       Template.parse("{% include 'loop' %}").render!
     end
   end
@@ -217,6 +217,17 @@ class IncludeTagTest < Minitest::Test
     end
   end
 
+  def test_render_raise_argument_error_when_template_is_undefined
+    assert_raises(Liquid::ArgumentError) do
+      template = Liquid::Template.parse('{% include undefined_variable %}')
+      template.render!
+    end
+    assert_raises(Liquid::ArgumentError) do
+      template = Liquid::Template.parse('{% include nil %}')
+      template.render!
+    end
+  end
+
   def test_including_via_variable_value
     assert_template_result "from TestFileSystem", "{% assign page = 'pick_a_source' %}{% include page %}"
 
@@ -224,4 +235,11 @@ class IncludeTagTest < Minitest::Test
 
     assert_template_result "Product: Draft 151cm ", "{% assign page = 'product' %}{% include page for foo %}", "foo" => { 'title' => 'Draft 151cm' }
   end
+
+  def test_including_with_strict_variables
+    template = Liquid::Template.parse("{% include 'simple' %}", error_mode: :warn)
+    template.render(nil, strict_variables: true)
+
+    assert_equal [], template.errors
+  end
 end # IncludeTagTest

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/tags/standard_tag_test.rb

@@ -293,9 +293,4 @@ class StandardTagTest < Minitest::Test
   def test_multiline_tag
     assert_template_result '0 1 2 3', "0{%\nfor i in (1..3)\n%} {{\ni\n}}{%\nendfor\n%}"
   end
-
-  def test_spaceless
-    html = "<a>\n\n   <b>  \n  <c>a</c> \r\n   </b>   </a>"
-    assert_template_result '<a><b><c>a</c></b></a>', "{% spaceless %}#{html}{% endspaceless %}"
-  end
 end # StandardTagTest

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
@@ -198,17 +215,118 @@ class TemplateTest < Minitest::Test
     assert_equal 'ruby error in drop', e.message
   end
 
-  def test_exception_handler_doesnt_reraise_if_it_returns_false
+  def test_exception_renderer_that_returns_string
     exception = nil
-    Template.parse("{{ 1 | divided_by: 0 }}").render({}, exception_handler: ->(e) { exception = e; false })
+    handler = ->(e) { exception = e; '<!-- error -->' }
+
+    output = Template.parse("{{ 1 | divided_by: 0 }}").render({}, exception_renderer: handler)
+
     assert exception.is_a?(Liquid::ZeroDivisionError)
+    assert_equal '<!-- error -->', output
   end
 
-  def test_exception_handler_does_reraise_if_it_returns_true
+  def test_exception_renderer_that_raises
     exception = nil
     assert_raises(Liquid::ZeroDivisionError) do
-      Template.parse("{{ 1 | divided_by: 0 }}").render({}, exception_handler: ->(e) { exception = e; true })
+      Template.parse("{{ 1 | divided_by: 0 }}").render({}, exception_renderer: ->(e) { exception = e; raise })
     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_nil_value_does_not_raise
+    Liquid::Template.error_mode = :strict
+    t = Template.parse("some{{x}}thing")
+    result = t.render!({ 'x' => nil }, strict_variables: true)
+
+    assert_equal 0, t.errors.count
+    assert_equal 'something', result
+  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/integration/trim_mode_test.rb

@@ -0,0 +1,525 @@
+require 'test_helper'
+
+class TrimModeTest < Minitest::Test
+  include Liquid
+
+  # Make sure the trim isn't applied to standard output
+  def test_standard_output
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {{ 'John' }}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          John
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_variable_output_with_multiple_blank_lines
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+
+
+          {{- 'John' -}}
+
+
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>John</p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_tag_output_with_multiple_blank_lines
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+
+
+          {%- if true -%}
+          yes
+          {%- endif -%}
+
+
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>yes</p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  # Make sure the trim isn't applied to standard tags
+  def test_standard_tags
+    whitespace = '          '
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {% if true %}
+          yes
+          {% endif %}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+#{whitespace}
+          yes
+#{whitespace}
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {% if false %}
+          no
+          {% endif %}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+#{whitespace}
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  # Make sure the trim isn't too agressive
+  def test_no_trim_output
+    text = '<p>{{- \'John\' -}}</p>'
+    expected = '<p>John</p>'
+    assert_template_result(expected, text)
+  end
+
+  # Make sure the trim isn't too agressive
+  def test_no_trim_tags
+    text = '<p>{%- if true -%}yes{%- endif -%}</p>'
+    expected = '<p>yes</p>'
+    assert_template_result(expected, text)
+
+    text = '<p>{%- if false -%}no{%- endif -%}</p>'
+    expected = '<p></p>'
+    assert_template_result(expected, text)
+  end
+
+  def test_single_line_outer_tag
+    text = '<p> {%- if true %} yes {% endif -%} </p>'
+    expected = '<p> yes </p>'
+    assert_template_result(expected, text)
+
+    text = '<p> {%- if false %} no {% endif -%} </p>'
+    expected = '<p></p>'
+    assert_template_result(expected, text)
+  end
+
+  def test_single_line_inner_tag
+    text = '<p> {% if true -%} yes {%- endif %} </p>'
+    expected = '<p> yes </p>'
+    assert_template_result(expected, text)
+
+    text = '<p> {% if false -%} no {%- endif %} </p>'
+    expected = '<p>  </p>'
+    assert_template_result(expected, text)
+  end
+
+  def test_single_line_post_tag
+    text = '<p> {% if true -%} yes {% endif -%} </p>'
+    expected = '<p> yes </p>'
+    assert_template_result(expected, text)
+
+    text = '<p> {% if false -%} no {% endif -%} </p>'
+    expected = '<p> </p>'
+    assert_template_result(expected, text)
+  end
+
+  def test_single_line_pre_tag
+    text = '<p> {%- if true %} yes {%- endif %} </p>'
+    expected = '<p> yes </p>'
+    assert_template_result(expected, text)
+
+    text = '<p> {%- if false %} no {%- endif %} </p>'
+    expected = '<p> </p>'
+    assert_template_result(expected, text)
+  end
+
+  def test_pre_trim_output
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {{- 'John' }}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>John
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_pre_trim_tags
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {%- if true %}
+          yes
+          {%- endif %}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          yes
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {%- if false %}
+          no
+          {%- endif %}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_post_trim_output
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {{ 'John' -}}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          John</p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_post_trim_tags
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {% if true -%}
+          yes
+          {% endif -%}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          yes
+          </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {% if false -%}
+          no
+          {% endif -%}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_pre_and_post_trim_tags
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {%- if true %}
+          yes
+          {% endif -%}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          yes
+          </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {%- if false %}
+          no
+          {% endif -%}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p></p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_post_and_pre_trim_tags
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {% if true -%}
+          yes
+          {%- endif %}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          yes
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+
+    whitespace = '          '
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {% if false -%}
+          no
+          {%- endif %}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+#{whitespace}
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_trim_output
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {{- 'John' -}}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>John</p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_trim_tags
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {%- if true -%}
+          yes
+          {%- endif -%}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>yes</p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {%- if false -%}
+          no
+          {%- endif -%}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p></p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_whitespace_trim_output
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {{- 'John' -}},
+          {{- '30' -}}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>John,30</p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_whitespace_trim_tags
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {%- if true -%}
+          yes
+          {%- endif -%}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>yes</p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {%- if false -%}
+          no
+          {%- endif -%}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p></p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_complex_trim_output
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {{- 'John' -}}
+          {{- '30' -}}
+        </p>
+        <b>
+          {{ 'John' -}}
+          {{- '30' }}
+        </b>
+        <i>
+          {{- 'John' }}
+          {{ '30' -}}
+        </i>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>John30</p>
+        <b>
+          John30
+        </b>
+        <i>John
+          30</i>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_complex_trim
+    text = <<-END_TEMPLATE
+      <div>
+        {%- if true -%}
+          {%- if true -%}
+            <p>
+              {{- 'John' -}}
+            </p>
+          {%- endif -%}
+        {%- endif -%}
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div><p>John</p></div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_raw_output
+    whitespace = '        '
+    text = <<-END_TEMPLATE
+      <div>
+        {% raw %}
+          {%- if true -%}
+            <p>
+              {{- 'John' -}}
+            </p>
+          {%- endif -%}
+        {% endraw %}
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+#{whitespace}
+          {%- if true -%}
+            <p>
+              {{- 'John' -}}
+            </p>
+          {%- endif -%}
+#{whitespace}
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+end # TrimModeTest

test/integration/variable_test.rb

@@ -89,4 +89,8 @@ class VariableTest < Minitest::Test
   def test_multiline_variable
     assert_equal 'worked', Template.parse("{{\ntest\n}}").render!('test' => 'worked')
   end
+
+  def test_render_symbol
+    assert_template_result 'bar', '{{ foo }}', 'foo' => :bar
+  end
 end

test/test_helper.rb

@@ -2,7 +2,6 @@
 
 ENV["MT_NO_EXPECTATIONS"] = "1"
 require 'minitest/autorun'
-require 'spy/integration'
 
 $LOAD_PATH.unshift(File.join(File.expand_path(__dir__), '..', 'lib'))
 require 'liquid.rb'

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
@@ -60,34 +64,42 @@ class ConditionUnitTest < Minitest::Test
     assert_evaluates_argument_error '1', '<=', 0
   end
 
+  def test_hash_compare_backwards_compatibility
+    assert_nil Condition.new({}, '>', 2).evaluate
+    assert_nil Condition.new(2, '>', {}).evaluate
+    assert_equal false, Condition.new({}, '==', 2).evaluate
+    assert_equal true, Condition.new({ 'a' => 1 }, '==', { 'a' => 1 }).evaluate
+    assert_equal true, Condition.new({ 'a' => 2 }, 'contains', 'a').evaluate
+  end
+
   def test_contains_works_on_arrays
     @context = Liquid::Context.new
     @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 +133,8 @@ 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 +143,24 @@ 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

@@ -70,10 +70,6 @@ class ContextUnitTest < Minitest::Test
     @context = Liquid::Context.new
   end
 
-  def teardown
-    Spy.teardown
-  end
-
   def test_variables
     @context['string'] = 'string'
     assert_equal 'string', @context['string']
@@ -98,12 +94,12 @@ class ContextUnitTest < Minitest::Test
     assert_equal false, @context['bool']
 
     @context['nil'] = nil
-    assert_equal nil, @context['nil']
-    assert_equal nil, @context['nil']
+    assert_nil @context['nil']
+    assert_nil @context['nil']
   end
 
   def test_variables_not_existing
-    assert_equal nil, @context['does_not_exist']
+    assert_nil @context['does_not_exist']
   end
 
   def test_scoping
@@ -185,7 +181,7 @@ class ContextUnitTest < Minitest::Test
     @context['test'] = 'test'
     assert_equal 'test', @context['test']
     @context.pop
-    assert_equal nil, @context['test']
+    assert_nil @context['test']
   end
 
   def test_hierachical_data
@@ -267,7 +263,7 @@ 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]']
@@ -300,12 +296,12 @@ class ContextUnitTest < Minitest::Test
     @context['hash'] = { 'first' => 'Hello' }
 
     assert_equal 1, @context['array.first']
-    assert_equal nil, @context['array["first"]']
+    assert_nil @context['array["first"]']
     assert_equal 'Hello', @context['hash["first"]']
   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']
@@ -450,14 +446,10 @@ class ContextUnitTest < Minitest::Test
     assert_equal @context, @context['category'].context
   end
 
-  def test_use_empty_instead_of_any_in_interrupt_handling_to_avoid_lots_of_unnecessary_object_allocations
-    mock_any = Spy.on_instance_method(Array, :any?)
-    mock_empty = Spy.on_instance_method(Array, :empty?)
-
-    @context.interrupt?
-
-    refute mock_any.has_been_called?
-    assert mock_empty.has_been_called?
+  def test_interrupt_avoids_object_allocations
+    assert_no_object_allocations do
+      @context.interrupt?
+    end
   end
 
   def test_context_initialization_with_a_proc_in_environment
@@ -466,4 +458,32 @@ 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
+
+  private
+
+  def assert_no_object_allocations
+    unless RUBY_ENGINE == 'ruby'
+      skip "stackprof needed to count object allocations"
+    end
+    require 'stackprof'
+
+    profile = StackProf.run(mode: :object) do
+      yield
+    end
+    assert_equal 0, profile[:samples]
+  end
 end # ContextTest

test/unit/lexer_unit_test.rb

@@ -19,7 +19,7 @@ class LexerUnitTest < Minitest::Test
   end
 
   def test_comparison
-    tokens = Lexer.new('== <> contains').tokenize
+    tokens = Lexer.new('== <> contains ').tokenize
     assert_equal [[:comparison, '=='], [:comparison, '<>'], [:comparison, 'contains'], [:end_of_string]], tokens
   end
 

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 +77,88 @@ 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
+
+  module LateAddedFilter
+    def late_added_filter(input)
+      "filtered"
+    end
+  end
+
+  def test_global_filter_clears_cache
+    assert_equal 'input', Strainer.create(nil).invoke('late_added_filter', 'input')
+    Strainer.global_filter(LateAddedFilter)
+    assert_equal 'filtered', Strainer.create(nil).invoke('late_added_filter', 'input')
+  end
+
+  def test_add_filter_does_not_include_already_included_module
+    mod = Module.new do
+      class << self
+        attr_accessor :include_count
+        def included(mod)
+          self.include_count += 1
+        end
+      end
+      self.include_count = 0
+    end
+    strainer = Context.new.strainer
+    strainer.class.add_filter(mod)
+    strainer.class.add_filter(mod)
+    assert_equal 1, mod.include_count
+  end
 end # StrainerTest

test/unit/tag_unit_test.rb

@@ -4,13 +4,18 @@ class TagUnitTest < Minitest::Test
   include Liquid
 
   def test_tag
-    tag = Tag.parse('tag', [], [], {})
+    tag = Tag.parse('tag', "", Tokenizer.new(""), ParseContext.new)
     assert_equal 'liquid::tag', tag.name
     assert_equal '', tag.render(Context.new)
   end
 
   def test_return_raw_text_of_tag
-    tag = Tag.parse("long_tag", "param1, param2, param3", [], {})
+    tag = Tag.parse("long_tag", "param1, param2, param3", Tokenizer.new(""), ParseContext.new)
     assert_equal("long_tag param1, param2, param3", tag.raw)
   end
+
+  def test_tag_name_should_return_name_of_the_tag
+    tag = Tag.parse("some_tag", "", Tokenizer.new(""), ParseContext.new)
+    assert_equal 'some_tag', tag.tag_name
+  end
 end

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

test/unit/tokenizer_unit_test.rb

@@ -22,20 +22,34 @@ class TokenizerTest < Minitest::Test
   end
 
   def test_calculate_line_numbers_per_token_with_profiling
-    assert_equal [1],       tokenize("{{funk}}", true).map(&:line_number)
-    assert_equal [1, 1, 1], tokenize(" {{funk}} ", true).map(&:line_number)
-    assert_equal [1, 2, 2], tokenize("\n{{funk}}\n", true).map(&:line_number)
-    assert_equal [1, 1, 3], tokenize(" {{\n funk \n}} ", true).map(&:line_number)
+    assert_equal [1],       tokenize_line_numbers("{{funk}}")
+    assert_equal [1, 1, 1], tokenize_line_numbers(" {{funk}} ")
+    assert_equal [1, 2, 2], tokenize_line_numbers("\n{{funk}}\n")
+    assert_equal [1, 1, 3], tokenize_line_numbers(" {{\n funk \n}} ")
   end
 
   private
 
-  def tokenize(source, line_numbers = false)
-    tokenizer = Liquid::Tokenizer.new(source, line_numbers)
+  def tokenize(source)
+    tokenizer = Liquid::Tokenizer.new(source)
     tokens = []
     while t = tokenizer.shift
       tokens << t
     end
     tokens
   end
+
+  def tokenize_line_numbers(source)
+    tokenizer = Liquid::Tokenizer.new(source, true)
+    line_numbers = []
+    loop do
+      line_number = tokenizer.line_number
+      if tokenizer.shift
+        line_numbers << line_number
+      else
+        break
+      end
+    end
+    line_numbers
+  end
 end

test/unit/variable_unit_test.rb

@@ -4,133 +4,133 @@ class VariableUnitTest < Minitest::Test
   include Liquid
 
   def test_variable
-    var = Variable.new('hello')
+    var = create_variable('hello')
     assert_equal VariableLookup.new('hello'), var.name
   end
 
   def test_filters
-    var = Variable.new('hello | textileze')
+    var = create_variable('hello | textileze')
     assert_equal VariableLookup.new('hello'), var.name
     assert_equal [['textileze', []]], var.filters
 
-    var = Variable.new('hello | textileze | paragraph')
+    var = create_variable('hello | textileze | paragraph')
     assert_equal VariableLookup.new('hello'), var.name
     assert_equal [['textileze', []], ['paragraph', []]], var.filters
 
-    var = Variable.new(%( hello | strftime: '%Y'))
+    var = create_variable(%( hello | strftime: '%Y'))
     assert_equal VariableLookup.new('hello'), var.name
     assert_equal [['strftime', ['%Y']]], var.filters
 
-    var = Variable.new(%( 'typo' | link_to: 'Typo', true ))
+    var = create_variable(%( 'typo' | link_to: 'Typo', true ))
     assert_equal 'typo', var.name
     assert_equal [['link_to', ['Typo', true]]], var.filters
 
-    var = Variable.new(%( 'typo' | link_to: 'Typo', false ))
+    var = create_variable(%( 'typo' | link_to: 'Typo', false ))
     assert_equal 'typo', var.name
     assert_equal [['link_to', ['Typo', false]]], var.filters
 
-    var = Variable.new(%( 'foo' | repeat: 3 ))
+    var = create_variable(%( 'foo' | repeat: 3 ))
     assert_equal 'foo', var.name
     assert_equal [['repeat', [3]]], var.filters
 
-    var = Variable.new(%( 'foo' | repeat: 3, 3 ))
+    var = create_variable(%( 'foo' | repeat: 3, 3 ))
     assert_equal 'foo', var.name
     assert_equal [['repeat', [3, 3]]], var.filters
 
-    var = Variable.new(%( 'foo' | repeat: 3, 3, 3 ))
+    var = create_variable(%( 'foo' | repeat: 3, 3, 3 ))
     assert_equal 'foo', var.name
     assert_equal [['repeat', [3, 3, 3]]], var.filters
 
-    var = Variable.new(%( hello | strftime: '%Y, okay?'))
+    var = create_variable(%( hello | strftime: '%Y, okay?'))
     assert_equal VariableLookup.new('hello'), var.name
     assert_equal [['strftime', ['%Y, okay?']]], var.filters
 
-    var = Variable.new(%( hello | things: "%Y, okay?", 'the other one'))
+    var = create_variable(%( hello | things: "%Y, okay?", 'the other one'))
     assert_equal VariableLookup.new('hello'), var.name
     assert_equal [['things', ['%Y, okay?', 'the other one']]], var.filters
   end
 
   def test_filter_with_date_parameter
-    var = Variable.new(%( '2006-06-06' | date: "%m/%d/%Y"))
+    var = create_variable(%( '2006-06-06' | date: "%m/%d/%Y"))
     assert_equal '2006-06-06', var.name
     assert_equal [['date', ['%m/%d/%Y']]], var.filters
   end
 
   def test_filters_without_whitespace
-    var = Variable.new('hello | textileze | paragraph')
+    var = create_variable('hello | textileze | paragraph')
     assert_equal VariableLookup.new('hello'), var.name
     assert_equal [['textileze', []], ['paragraph', []]], var.filters
 
-    var = Variable.new('hello|textileze|paragraph')
+    var = create_variable('hello|textileze|paragraph')
     assert_equal VariableLookup.new('hello'), var.name
     assert_equal [['textileze', []], ['paragraph', []]], var.filters
 
-    var = Variable.new("hello|replace:'foo','bar'|textileze")
+    var = create_variable("hello|replace:'foo','bar'|textileze")
     assert_equal VariableLookup.new('hello'), var.name
     assert_equal [['replace', ['foo', 'bar']], ['textileze', []]], var.filters
   end
 
   def test_symbol
-    var = Variable.new("http://disney.com/logo.gif | image: 'med' ", error_mode: :lax)
+    var = create_variable("http://disney.com/logo.gif | image: 'med' ", error_mode: :lax)
     assert_equal VariableLookup.new('http://disney.com/logo.gif'), var.name
     assert_equal [['image', ['med']]], var.filters
   end
 
   def test_string_to_filter
-    var = Variable.new("'http://disney.com/logo.gif' | image: 'med' ")
+    var = create_variable("'http://disney.com/logo.gif' | image: 'med' ")
     assert_equal 'http://disney.com/logo.gif', var.name
     assert_equal [['image', ['med']]], var.filters
   end
 
   def test_string_single_quoted
-    var = Variable.new(%( "hello" ))
+    var = create_variable(%( "hello" ))
     assert_equal 'hello', var.name
   end
 
   def test_string_double_quoted
-    var = Variable.new(%( 'hello' ))
+    var = create_variable(%( 'hello' ))
     assert_equal 'hello', var.name
   end
 
   def test_integer
-    var = Variable.new(%( 1000 ))
+    var = create_variable(%( 1000 ))
     assert_equal 1000, var.name
   end
 
   def test_float
-    var = Variable.new(%( 1000.01 ))
+    var = create_variable(%( 1000.01 ))
     assert_equal 1000.01, var.name
   end
 
   def test_dashes
-    assert_equal VariableLookup.new('foo-bar'), Variable.new('foo-bar').name
-    assert_equal VariableLookup.new('foo-bar-2'), Variable.new('foo-bar-2').name
+    assert_equal VariableLookup.new('foo-bar'), create_variable('foo-bar').name
+    assert_equal VariableLookup.new('foo-bar-2'), create_variable('foo-bar-2').name
 
     with_error_mode :strict do
-      assert_raises(Liquid::SyntaxError) { Variable.new('foo - bar') }
-      assert_raises(Liquid::SyntaxError) { Variable.new('-foo') }
-      assert_raises(Liquid::SyntaxError) { Variable.new('2foo') }
+      assert_raises(Liquid::SyntaxError) { create_variable('foo - bar') }
+      assert_raises(Liquid::SyntaxError) { create_variable('-foo') }
+      assert_raises(Liquid::SyntaxError) { create_variable('2foo') }
     end
   end
 
   def test_string_with_special_chars
-    var = Variable.new(%( 'hello! $!@.;"ddasd" ' ))
+    var = create_variable(%( 'hello! $!@.;"ddasd" ' ))
     assert_equal 'hello! $!@.;"ddasd" ', var.name
   end
 
   def test_string_dot
-    var = Variable.new(%( test.test ))
+    var = create_variable(%( test.test ))
     assert_equal VariableLookup.new('test.test'), var.name
   end
 
   def test_filter_with_keyword_arguments
-    var = Variable.new(%( hello | things: greeting: "world", farewell: 'goodbye'))
+    var = create_variable(%( hello | things: greeting: "world", farewell: 'goodbye'))
     assert_equal VariableLookup.new('hello'), var.name
     assert_equal [['things', [], { 'greeting' => 'world', 'farewell' => 'goodbye' }]], var.filters
   end
 
   def test_lax_filter_argument_parsing
-    var = Variable.new(%( number_of_comments | pluralize: 'comment': 'comments' ), error_mode: :lax)
+    var = create_variable(%( number_of_comments | pluralize: 'comment': 'comments' ), error_mode: :lax)
     assert_equal VariableLookup.new('number_of_comments'), var.name
     assert_equal [['pluralize', ['comment', 'comments']]], var.filters
   end
@@ -138,13 +138,13 @@ class VariableUnitTest < Minitest::Test
   def test_strict_filter_argument_parsing
     with_error_mode(:strict) do
       assert_raises(SyntaxError) do
-        Variable.new(%( number_of_comments | pluralize: 'comment': 'comments' ))
+        create_variable(%( number_of_comments | pluralize: 'comment': 'comments' ))
       end
     end
   end
 
   def test_output_raw_source_of_variable
-    var = Variable.new(%( name_of_variable | upcase ))
+    var = create_variable(%( name_of_variable | upcase ))
     assert_equal " name_of_variable | upcase ", var.raw
   end
 
@@ -153,4 +153,10 @@ class VariableUnitTest < Minitest::Test
     assert_equal 'a', lookup.name
     assert_equal ['b', 'c'], lookup.lookups
   end
+
+  private
+
+  def create_variable(markup, options = {})
+    Variable.new(markup, ParseContext.new(options))
+  end
 end