styling fixes

* Disable rendering of tag based on register

* Improvements to disable tag

* Resolve disbale tag tests

* Test disable_tags register

* disabled_tags is now always avaiable

* Allow multiple tags to be disabled at once

* Move disabled check to block_body

* Code improvements

* Remove redundant nil check

* Improve disabled tag error output

* Improve disable tag API

* Code improvements

* Switch disabled? to not mutate output

* Fix array handling shortcut in disable_tags

.rubocop.yml

@@ -1,5 +1,5 @@
 inherit_from:
-  - https://shopify.github.io/ruby-style-guide/rubocop.yml
+  - 'https://shopify.github.io/ruby-style-guide/rubocop.yml'
   - .rubocop_todo.yml
 
 require: rubocop-performance
@@ -8,9 +8,10 @@ Performance:
   Enabled: true
 
 AllCops:
+  TargetRubyVersion: 2.4
   Exclude:
     - 'vendor/bundle/**/*'
-      
+
 Naming/MethodName:
   Exclude:
-    - 'example/server/liquid_servlet.rb'
+    - 'example/server/liquid_servlet.rb'

.rubocop_todo.yml

@@ -6,26 +6,6 @@
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
-# Offense count: 2
-Lint/AmbiguousOperator:
-  Exclude:
-    - 'test/unit/condition_unit_test.rb'
-
-# Offense count: 21
-# Configuration parameters: AllowSafeAssignment.
-Lint/AssignmentInCondition:
-  Exclude:
-    - 'lib/liquid/block_body.rb'
-    - 'lib/liquid/lexer.rb'
-    - 'lib/liquid/standardfilters.rb'
-    - 'lib/liquid/tags/for.rb'
-    - 'lib/liquid/tags/if.rb'
-    - 'lib/liquid/tags/raw.rb'
-    - 'lib/liquid/variable.rb'
-    - 'performance/profile.rb'
-    - 'test/test_helper.rb'
-    - 'test/unit/tokenizer_unit_test.rb'
-
 # Offense count: 2
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle.
@@ -34,17 +14,6 @@ Lint/InheritException:
   Exclude:
     - 'lib/liquid/interrupts.rb'
 
-# Offense count: 2
-Lint/UselessAssignment:
-  Exclude:
-    - 'performance/shopify/database.rb'
-
-# Offense count: 1
-# Configuration parameters: CheckForMethodsWithNoSideEffects.
-Lint/Void:
-  Exclude:
-    - 'lib/liquid/parse_context.rb'
-
 # Offense count: 98
 # Cop supports --auto-correct.
 # Configuration parameters: AutoCorrect, AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
@@ -76,19 +45,4 @@ Style/ClassVars:
   Exclude:
     - 'lib/liquid/condition.rb'
     - 'lib/liquid/strainer.rb'
-    - 'lib/liquid/template.rb'
+    - 'lib/liquid/template.rb'
-
-# Offense count: 1
-# Configuration parameters: AllowCoercion.
-Style/DateTime:
-  Exclude:
-    - 'test/unit/context_unit_test.rb'
-
-# Offense count: 9
-# Cop supports --auto-correct.
-# Configuration parameters: AllowAsExpressionSeparator.
-Style/Semicolon:
-  Exclude:
-    - 'test/integration/error_handling_test.rb'
-    - 'test/integration/template_test.rb'
-    - 'test/unit/context_unit_test.rb'

.travis.yml

@@ -7,8 +7,6 @@ rvm:
   - &latest_ruby 2.6
   - 2.7
   - ruby-head
-  - jruby-head
-  - truffleruby
 
 matrix:
   include:
@@ -17,8 +15,6 @@ matrix:
       name: Profiling Memory Usage
   allow_failures:
     - rvm: ruby-head
-    - rvm: jruby-head
-    - rvm: truffleruby
 
 branches:
   only:

lib/liquid.rb

@@ -78,7 +78,10 @@ require 'liquid/tokenizer'
 require 'liquid/parse_context'
 require 'liquid/partial_cache'
 require 'liquid/usage'
+require 'liquid/register'
+require 'liquid/static_registers'
 
 # Load all the tags of the standard library
 #
 Dir["#{__dir__}/liquid/tags/*.rb"].each { |f| require f }
+Dir["#{__dir__}/liquid/registers/*.rb"].each { |f| require f }

lib/liquid/block_body.rb

@@ -27,7 +27,7 @@ module Liquid
     end
 
     private def parse_for_liquid_tag(tokenizer, parse_context)
-      while token = tokenizer.shift
+      while (token = tokenizer.shift)
         unless token.empty? || token =~ WhitespaceOrNothing
           unless token =~ LiquidTagToken
             # line isn't empty but didn't match tag syntax, yield and let the
@@ -36,7 +36,7 @@ module Liquid
           end
           tag_name = Regexp.last_match(1)
           markup = Regexp.last_match(2)
-          unless tag = registered_tags[tag_name]
+          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
@@ -52,7 +52,7 @@ module Liquid
     end
 
     private def parse_for_document(tokenizer, parse_context, &block)
-      while token = tokenizer.shift
+      while (token = tokenizer.shift)
         next if token.empty?
         case
         when token.start_with?(TAGSTART)
@@ -74,7 +74,7 @@ module Liquid
             next parse_for_liquid_tag(liquid_tag_tokenizer, parse_context, &block)
           end
 
-          unless tag = registered_tags[tag_name]
+          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
@@ -122,7 +122,7 @@ module Liquid
       context.resource_limits.render_score += @nodelist.length
 
       idx = 0
-      while node = @nodelist[idx]
+      while (node = @nodelist[idx])
         previous_output_size = output.bytesize
 
         case node
@@ -154,7 +154,13 @@ module Liquid
     private
 
     def render_node(context, output, node)
-      node.render_to_output_buffer(context, output)
+      if node.disabled?(context)
+        output << node.disabled_error_message
+        return
+      end
+      disable_tags(context, node.disabled_tags) do
+        node.render_to_output_buffer(context, output)
+      end
     rescue UndefinedVariable, UndefinedDropMethod, UndefinedFilter => e
       context.handle_error(e, node.line_number)
     rescue ::StandardError => e
@@ -162,6 +168,11 @@ module Liquid
       output << context.handle_error(e, line_number)
     end
 
+    def disable_tags(context, tags, &block)
+      return yield if tags.empty?
+      context.registers[:disabled_tags].disable(tags, &block)
+    end
+
     def raise_if_resource_limits_reached(context, length)
       context.resource_limits.render_length += length
       return unless context.resource_limits.reached?

lib/liquid/context.rb

@@ -18,18 +18,17 @@ module Liquid
     attr_accessor :exception_renderer, :template_name, :partial, :global_filter, :strict_variables, :strict_filters
 
     # rubocop:disable Metrics/ParameterLists
-    def self.build(environments: {}, outer_scope: {}, registers: {}, rethrow_errors: false, resource_limits: nil, static_registers: {}, static_environments: {})
+    def self.build(environments: {}, outer_scope: {}, registers: {}, rethrow_errors: false, resource_limits: nil, static_environments: {})
-      new(environments, outer_scope, registers, rethrow_errors, resource_limits, static_registers, static_environments)
+      new(environments, outer_scope, registers, rethrow_errors, resource_limits, static_environments)
     end
 
-    def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil, static_registers = {}, static_environments = {})
+    def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil, static_environments = {})
       @environments = [environments]
       @environments.flatten!
 
       @static_environments = [static_environments].flat_map(&:freeze).freeze
       @scopes              = [(outer_scope || {})]
       @registers           = registers
-      @static_registers    = static_registers.freeze
       @errors              = []
       @partial             = false
       @strict_variables    = false
@@ -137,7 +136,7 @@ module Liquid
       Context.build(
         resource_limits: resource_limits,
         static_environments: static_environments,
-        static_registers: static_registers
+        registers: StaticRegisters.new(registers)
       ).tap do |subcontext|
         subcontext.base_scope_depth = base_scope_depth + 1
         subcontext.exception_renderer = exception_renderer

lib/liquid/drop.rb

@@ -69,7 +69,7 @@ module Liquid
 
         if include?(Enumerable)
           blacklist += Enumerable.public_instance_methods
-          blacklist -= [:sort, :count, :first, :min, :max, :include?]
+          blacklist -= [:sort, :count, :first, :min, :max]
         end
 
         whitelist = [:to_liquid] + (public_instance_methods - blacklist)

lib/liquid/file_system.rb

@@ -59,7 +59,7 @@ module Liquid
     end
 
     def full_path(template_path)
-      raise FileSystemError, "Illegal template name '#{template_path}'" unless template_path =~ %r{\A[^./][a-zA-Z0-9_/]+\z}
+      raise FileSystemError, "Illegal template name '#{template_path}'" unless %r{\A[^./][a-zA-Z0-9_/]+\z}.match?(template_path)
 
       full_path = if template_path.include?('/')
         File.join(root, File.dirname(template_path), @pattern % File.basename(template_path))

lib/liquid/lexer.rb

@@ -33,15 +33,21 @@ module Liquid
       until @ss.eos?
         @ss.skip(WHITESPACE_OR_NOTHING)
         break if @ss.eos?
-        tok = if t = @ss.scan(COMPARISON_OPERATOR) then [:comparison, t]
+        tok = if (t = @ss.scan(COMPARISON_OPERATOR))
-        elsif t = @ss.scan(SINGLE_STRING_LITERAL) then [:string, t]
+          [:comparison, t]
-        elsif t = @ss.scan(DOUBLE_STRING_LITERAL) then [:string, t]
+        elsif (t = @ss.scan(SINGLE_STRING_LITERAL))
-        elsif t = @ss.scan(NUMBER_LITERAL) then [:number, t]
+          [:string, t]
-        elsif t = @ss.scan(IDENTIFIER) then [:id, t]
+        elsif (t = @ss.scan(DOUBLE_STRING_LITERAL))
-        elsif t = @ss.scan(DOTDOT) then [:dotdot, t]
+          [:string, t]
+        elsif (t = @ss.scan(NUMBER_LITERAL))
+          [:number, t]
+        elsif (t = @ss.scan(IDENTIFIER))
+          [:id, t]
+        elsif (t = @ss.scan(DOTDOT))
+          [:dotdot, t]
         else
           c = @ss.getch
-          if s = SPECIALS[c]
+          if (s = SPECIALS[c])
             [s, c]
           else
             raise SyntaxError, "Unexpected character #{c}"

lib/liquid/locales/en.yml

@@ -25,3 +25,5 @@
       render: "Syntax error in tag 'render' - Template name must be a quoted string"
     argument:
       include: "Argument error in tag 'include' - Illegal template name"
+    disabled:
+      tag: "usage is not allowed in this context"

lib/liquid/parse_context.rb

@@ -21,7 +21,6 @@ module Liquid
       @partial = value
       @options = value ? partial_options : @template_options
       @error_mode = @options[:error_mode] || Template.error_mode
-      value
     end
 
     def partial_options

lib/liquid/register.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+module Liquid
+  class Register
+  end
+end

lib/liquid/registers/disabled_tags.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+module Liquid
+  class DisabledTags < Register
+    def initialize
+      @disabled_tags = {}
+    end
+
+    def disabled?(tag)
+      @disabled_tags.key?(tag) && @disabled_tags[tag] > 0
+    end
+
+    def disable(tags)
+      tags.each(&method(:increment))
+      yield
+    ensure
+      tags.each(&method(:decrement))
+    end
+
+    private
+
+    def increment(tag)
+      @disabled_tags[tag] ||= 0
+      @disabled_tags[tag] += 1
+    end
+
+    def decrement(tag)
+      @disabled_tags[tag] -= 1
+    end
+  end
+
+  Template.add_register(:disabled_tags, DisabledTags.new)
+end

lib/liquid/standardfilters.rb

@@ -193,6 +193,23 @@ module Liquid
       end
     end
 
+    # Sort elements of an array in numeric order
+    # provide optional property with which to sort an array of hashes or drops
+    def sort_numeric(input, property = nil)
+      ary = InputIterator.new(input)
+      if property.nil?
+        ary.sort do |a, b|
+          Utils.to_number(a) <=> Utils.to_number(b)
+        end
+      elsif ary.empty? # The next two cases assume a non-empty array.
+        []
+      elsif ary.first.respond_to?(:[]) && !ary.first[property].nil?
+        ary.sort do |a, b|
+          Utils.to_number(a[property]) <=> Utils.to_number(b[property])
+        end
+      end
+    end
+
     # Remove duplicate elements from an array
     # provide optional property with which to determine uniqueness
     def uniq(input, property = nil)
@@ -327,7 +344,7 @@ module Liquid
     def date(input, format)
       return input if format.to_s.empty?
 
-      return input unless date = Utils.to_date(input)
+      return input unless (date = Utils.to_date(input))
 
       date.strftime(format.to_s)
     end

lib/liquid/static_registers.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module Liquid
+  class StaticRegisters
+    attr_reader :static, :registers
+
+    def initialize(registers = {})
+      @static = registers.is_a?(StaticRegisters) ? registers.static : registers
+      @registers = {}
+    end
+
+    def []=(key, value)
+      @registers[key] = value
+    end
+
+    def [](key)
+      if @registers.key?(key)
+        @registers[key]
+      else
+        @static[key]
+      end
+    end
+
+    def delete(key)
+      @registers.delete(key)
+    end
+
+    def fetch(key, default = nil)
+      key?(key) ? self[key] : default
+    end
+
+    def key?(key)
+      @registers.key?(key) || @static.key?(key)
+    end
+  end
+end

lib/liquid/tag.rb

@@ -13,7 +13,15 @@ module Liquid
         tag
       end
 
+      def disable_tags(*tags)
+        disabled_tags.push(*tags)
+      end
+
       private :new
+
+      def disabled_tags
+        @disabled_tags ||= []
+      end
     end
 
     def initialize(tag_name, markup, parse_context)
@@ -38,6 +46,14 @@ module Liquid
       ''
     end
 
+    def disabled?(context)
+      context.registers[:disabled_tags].disabled?(tag_name)
+    end
+
+    def disabled_error_message
+      "#{tag_name} #{options[:locale].t('errors.disabled.tag')}"
+    end
+
     # For backwards compatibility with custom tags. In a future release, the semantics
     # of the `render_to_output_buffer` method will become the default and the `render`
     # method will be removed.
@@ -49,5 +65,9 @@ module Liquid
     def blank?
       false
     end
+
+    def disabled_tags
+      self.class.disabled_tags
+    end
   end
 end

lib/liquid/tags/for.rb

@@ -111,7 +111,7 @@ module Liquid
       @reversed = p.id?('reversed')
 
       while p.look(:id) && p.look(:colon, 1)
-        unless attribute = p.id?('limit') || p.id?('offset')
+        unless (attribute = p.id?('limit') || p.id?('offset'))
           raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_attribute")
         end
         p.consume

lib/liquid/tags/if.rb

@@ -94,7 +94,7 @@ module Liquid
     def parse_binary_comparisons(p)
       condition = parse_comparison(p)
       first_condition = condition
-      while op = (p.id?('and') || p.id?('or'))
+      while (op = (p.id?('and') || p.id?('or')))
         child_condition = parse_comparison(p)
         condition.send(op, child_condition)
         condition = child_condition
@@ -104,7 +104,7 @@ module Liquid
 
     def parse_comparison(p)
       a = Expression.parse(p.expression)
-      if op = p.consume?(:comparison)
+      if (op = p.consume?(:comparison))
         b = Expression.parse(p.expression)
         Condition.new(a, op, b)
       else

lib/liquid/tags/raw.rb

@@ -13,7 +13,7 @@ module Liquid
 
     def parse(tokens)
       @body = +''
-      while token = tokens.shift
+      while (token = tokens.shift)
         if token =~ FullTokenPossiblyInvalid
           @body << Regexp.last_match(1) if Regexp.last_match(1) != ""
           return if block_delimiter == Regexp.last_match(2)
@@ -40,7 +40,7 @@ module Liquid
     protected
 
     def ensure_valid_markup(tag_name, markup, parse_context)
-      unless markup =~ Syntax
+      unless Syntax.match?(markup)
         raise SyntaxError, parse_context.locale.t("errors.syntax.tag_unexpected_args", tag: tag_name)
       end
     end

lib/liquid/tags/render.rb

@@ -4,6 +4,8 @@ module Liquid
   class Render < Tag
     SYNTAX = /(#{QuotedString})#{QuotedFragment}*/o
 
+    disable_tags "include"
+
     attr_reader :template_name_expr, :attributes
 
     def initialize(tag_name, markup, options)
@@ -22,6 +24,10 @@ module Liquid
     end
 
     def render_to_output_buffer(context, output)
+      render_tag(context, output)
+    end
+
+    def render_tag(context, output)
       # Though we evaluate this here we will only ever parse it as a string literal.
       template_name = context.evaluate(@template_name_expr)
       raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name

lib/liquid/template.rb

@@ -92,6 +92,14 @@ module Liquid
         @tags ||= TagRegistry.new
       end
 
+      def add_register(name, klass)
+        registers[name.to_sym] = klass
+      end
+
+      def registers
+        @registers ||= {}
+      end
+
       def error_mode
         @error_mode ||= :lax
       end
@@ -191,18 +199,26 @@ module Liquid
 
       output = nil
 
+      context_register = context.registers.is_a?(StaticRegisters) ? context.registers.static : context.registers
+
       case args.last
       when Hash
         options = args.pop
         output = options[:output] if options[:output]
 
-        registers.merge!(options[:registers]) if options[:registers].is_a?(Hash)
+        options[:registers]&.each do |key, register|
+          context_register[key] = register
+        end
 
         apply_options_to_context(context, options)
       when Module, Array
         context.add_filters(args.pop)
       end
 
+      Template.registers.each do |key, register|
+        context_register[key] = register
+      end
+
       # Retrying a render resets resource usage
       context.resource_limits.reset
 

lib/liquid/utils.rb

@@ -52,7 +52,7 @@ module Liquid
       when Numeric
         obj
       when String
-        obj.strip =~ /\A-?\d+\.\d+\z/ ? BigDecimal(obj) : obj.to_i
+        /\A-?\d+\.\d+\z/.match?(obj.strip) ? BigDecimal(obj) : obj.to_i
       else
         if obj.respond_to?(:to_number)
           obj.to_number

lib/liquid/variable.rb

@@ -104,13 +104,21 @@ module Liquid
       output
     end
 
+    def disabled?(_context)
+      false
+    end
+
+    def disabled_tags
+      []
+    end
+
     private
 
     def parse_filter_expressions(filter_name, unparsed_args)
       filter_args = []
       keyword_args = nil
       unparsed_args.each do |a|
-        if matches = a.match(JustTagAttributes)
+        if (matches = a.match(JustTagAttributes))
           keyword_args ||= {}
           keyword_args[matches[1]] = Expression.parse(matches[2])
         else

performance/profile.rb

@@ -15,7 +15,7 @@ profiler.run
     end
   end
 
-  if profile_type == :cpu && graph_filename = ENV['GRAPH_FILENAME']
+  if profile_type == :cpu && (graph_filename = ENV['GRAPH_FILENAME'])
     File.open(graph_filename, 'w') do |f|
       StackProf::Report.new(results).print_graphviz(nil, f)
     end

performance/shopify/database.rb

@@ -32,8 +32,8 @@ module Database
       db['article']    = db['blog']['articles'].first
 
       db['cart']       = {
-        'total_price' => db['line_items'].values.inject(0) { |sum, item| sum += item['line_price'] * item['quantity'] },
+        'total_price' => db['line_items'].values.inject(0) { |sum, item| sum + item['line_price'] * item['quantity'] },
-        'item_count' => db['line_items'].values.inject(0) { |sum, item| sum += item['quantity'] },
+        'item_count' => db['line_items'].values.inject(0) { |sum, item| sum + item['quantity'] },
         'items' => db['line_items'].values,
       }
 

test/integration/drop_test.rb

@@ -272,4 +272,11 @@ class DropsTest < Minitest::Test
     assert_equal 'ProductDrop', Liquid::Template.parse("{{ product }}").render!('product' => ProductDrop.new)
     assert_equal 'EnumerableDrop', Liquid::Template.parse('{{ collection }}').render!('collection' => EnumerableDrop.new)
   end
+
+  def test_invokable_methods
+    assert_equal %w(to_liquid catchall user_input context texts).to_set, ProductDrop.invokable_methods
+    assert_equal %w(to_liquid scopes_as_array loop_pos scopes).to_set, ContextDrop.invokable_methods
+    assert_equal %w(to_liquid size max min first count).to_set, EnumerableDrop.invokable_methods
+    assert_equal %w(to_liquid max min sort count first).to_set, RealEnumerableDrop.invokable_methods
+  end
 end # DropsTest

test/integration/error_handling_test.rb

@@ -211,7 +211,10 @@ class ErrorHandlingTest < Minitest::Test
   def test_setting_default_exception_renderer
     old_exception_renderer = Liquid::Template.default_exception_renderer
     exceptions = []
-    Liquid::Template.default_exception_renderer = ->(e) { exceptions << e; '' }
+    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)
@@ -225,7 +228,10 @@ class ErrorHandlingTest < Minitest::Test
   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 }
+    handler = ->(e) {
+      exceptions << e
+      e.cause
+    }
 
     output = template.render({ 'errors' => ErrorDrop.new }, exception_renderer: handler)
 

test/integration/registers/disabled_tags_test.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class DisabledTagsTest < Minitest::Test
+  include Liquid
+
+  class DisableRaw < Block
+    disable_tags "raw"
+  end
+
+  class DisableRawEcho < Block
+    disable_tags "raw", "echo"
+  end
+
+  def test_disables_raw
+    with_custom_tag('disable', DisableRaw) do
+      assert_template_result 'raw usage is not allowed in this contextfoo', '{% disable %}{% raw %}Foobar{% endraw %}{% echo "foo" %}{% enddisable %}'
+    end
+  end
+
+  def test_disables_echo_and_raw
+    with_custom_tag('disable', DisableRawEcho) do
+      assert_template_result 'raw usage is not allowed in this contextecho usage is not allowed in this context', '{% disable %}{% raw %}Foobar{% endraw %}{% echo "foo" %}{% enddisable %}'
+    end
+  end
+end

test/integration/standard_filter_test.rb

@@ -198,6 +198,12 @@ 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_numeric
+    assert_equal ['1', '2', '3', '10'], @filters.sort_numeric(['10', '3', '2', '1'])
+    assert_equal [{ "a" => '1' }, { "a" => '2' }, { "a" => '3' }, { "a" => '10' }],
+      @filters.sort_numeric([{ "a" => '10' }, { "a" => '3' }, { "a" => '1' }, { "a" => '2' }], "a")
+  end
+
   def test_sort_with_nils
     assert_equal [1, 2, 3, 4, nil], @filters.sort([nil, 4, 3, 2, 1])
     assert_equal [{ "a" => 1 }, { "a" => 2 }, { "a" => 3 }, { "a" => 4 }, {}], @filters.sort([{ "a" => 4 }, { "a" => 3 }, {}, { "a" => 1 }, { "a" => 2 }], "a")
@@ -292,6 +298,10 @@ class StandardFiltersTest < Minitest::Test
     assert_equal [], @filters.sort_natural([], "a")
   end
 
+  def test_sort_numeric_empty_array
+    assert_equal [], @filters.sort_numeric([], "a")
+  end
+
   def test_sort_natural_invalid_property
     foo = [
       [1],

test/integration/tags/render_tag_test.rb

@@ -89,14 +89,12 @@ class RenderTagTest < Minitest::Test
     end
   end
 
-  def test_includes_and_renders_count_towards_the_same_recursion_limit
+  def test_sub_contexts_count_towards_the_same_recursion_limit
     Liquid::Template.file_system = StubFileSystem.new(
-      'loop_render' => '{% render "loop_include" %}',
+      'loop_render' => '{% render "loop_render" %}',
-      'loop_include' => '{% include "loop_render" %}'
     )
-
+    assert_raises Liquid::StackLevelError do
-    assert_raises Liquid::StackLevelError  do
+      Template.parse('{% render "loop_render" %}').render!
-      Template.parse('{% render "loop_include" %}').render!
     end
   end
 
@@ -148,4 +146,23 @@ class RenderTagTest < Minitest::Test
     Liquid::Template.file_system = StubFileSystem.new('decr' => '{% decrement %}')
     assert_template_result '-1-2-1', '{% decrement %}{% decrement %}{% render "decr" %}'
   end
+
+  def test_includes_will_not_render_inside_render_tag
+    Liquid::Template.file_system = StubFileSystem.new(
+      'foo' => 'bar',
+      'test_include' => '{% include "foo" %}'
+    )
+
+    assert_template_result 'include usage is not allowed in this context', '{% render "test_include" %}'
+  end
+
+  def test_includes_will_not_render_inside_nested_sibling_tags
+    Liquid::Template.file_system = StubFileSystem.new(
+      'foo' => 'bar',
+      'nested_render_with_sibling_include' => '{% render "test_include" %}{% include "foo" %}',
+      'test_include' => '{% include "foo" %}'
+    )
+
+    assert_template_result 'include usage is not allowed in this contextinclude usage is not allowed in this context', '{% render "nested_render_with_sibling_include" %}'
+  end
 end

test/integration/template_test.rb

@@ -81,7 +81,10 @@ class TemplateTest < Minitest::Test
 
   def test_lambda_is_called_once_from_persistent_assigns_over_multiple_parses_and_renders
     t = Template.new
-    t.assigns['number'] = -> { @global ||= 0; @global += 1 }
+    t.assigns['number'] = -> {
+      @global ||= 0
+      @global += 1
+    }
     assert_equal '1', t.parse("{{number}}").render!
     assert_equal '1', t.parse("{{number}}").render!
     assert_equal '1', t.render!
@@ -90,7 +93,10 @@ class TemplateTest < Minitest::Test
 
   def test_lambda_is_called_once_from_custom_assigns_over_multiple_parses_and_renders
     t = Template.new
-    assigns = { 'number' => -> { @global ||= 0; @global += 1 } }
+    assigns = { 'number' => -> {
+                              @global ||= 0
+                              @global += 1
+                            } }
     assert_equal '1', t.parse("{{number}}").render!(assigns)
     assert_equal '1', t.parse("{{number}}").render!(assigns)
     assert_equal '1', t.render!(assigns)
@@ -237,7 +243,10 @@ class TemplateTest < Minitest::Test
 
   def test_exception_renderer_that_returns_string
     exception = nil
-    handler = ->(e) { exception = e; '<!-- error -->' }
+    handler = ->(e) {
+      exception = e
+      '<!-- error -->'
+    }
 
     output = Template.parse("{{ 1 | divided_by: 0 }}").render({}, exception_renderer: handler)
 
@@ -248,7 +257,10 @@ class TemplateTest < Minitest::Test
   def test_exception_renderer_that_raises
     exception = nil
     assert_raises(Liquid::ZeroDivisionError) do
-      Template.parse("{{ 1 | divided_by: 0 }}").render({}, exception_renderer: ->(e) { exception = e; raise })
+      Template.parse("{{ 1 | divided_by: 0 }}").render({}, exception_renderer: ->(e) {
+                                                                                 exception = e
+                                                                                 raise
+                                                                               })
     end
     assert exception.is_a?(Liquid::ZeroDivisionError)
   end

test/test_helper.rb

@@ -9,7 +9,7 @@ require 'liquid.rb'
 require 'liquid/profiler'
 
 mode = :strict
-if env_mode = ENV['LIQUID_PARSER_MODE']
+if (env_mode = ENV['LIQUID_PARSER_MODE'])
   puts "-- #{env_mode.upcase} ERROR MODE"
   mode = env_mode.to_sym
 end

test/unit/condition_unit_test.rb

@@ -26,9 +26,9 @@ class ConditionUnitTest < Minitest::Test
     assert_evaluates_true 1, '<=', 1
     # negative numbers
     assert_evaluates_true 1, '>', -1
-    assert_evaluates_true -1, '<', 1
+    assert_evaluates_true(-1, '<', 1)
     assert_evaluates_true 1.0, '>', -1.0
-    assert_evaluates_true -1.0, '<', 1.0
+    assert_evaluates_true(-1.0, '<', 1.0)
   end
 
   def test_default_operators_evalute_false

test/unit/context_unit_test.rb

@@ -85,7 +85,7 @@ class ContextUnitTest < Minitest::Test
     @context['date'] = Date.today
     assert_equal Date.today, @context['date']
 
-    now = DateTime.now
+    now = Time.now
     @context['datetime'] = now
     assert_equal now, @context['datetime']
 
@@ -405,7 +405,11 @@ class ContextUnitTest < Minitest::Test
   end
 
   def test_lambda_is_called_once
-    @context['callcount'] = proc { @global ||= 0; @global += 1; @global.to_s }
+    @context['callcount'] = proc {
+      @global ||= 0
+      @global += 1
+      @global.to_s
+    }
 
     assert_equal '1', @context['callcount']
     assert_equal '1', @context['callcount']
@@ -415,7 +419,11 @@ class ContextUnitTest < Minitest::Test
   end
 
   def test_nested_lambda_is_called_once
-    @context['callcount'] = { "lambda" => proc { @global ||= 0; @global += 1; @global.to_s } }
+    @context['callcount'] = { "lambda" => proc {
+                                            @global ||= 0
+                                            @global += 1
+                                            @global.to_s
+                                          } }
 
     assert_equal '1', @context['callcount.lambda']
     assert_equal '1', @context['callcount.lambda']
@@ -425,7 +433,11 @@ class ContextUnitTest < Minitest::Test
   end
 
   def test_lambda_in_array_is_called_once
-    @context['callcount'] = [1, 2, proc { @global ||= 0; @global += 1; @global.to_s }, 4, 5]
+    @context['callcount'] = [1, 2, proc {
+                                     @global ||= 0
+                                     @global += 1
+                                     @global.to_s
+                                   }, 4, 5]
 
     assert_equal '1', @context['callcount[2]']
     assert_equal '1', @context['callcount[2]']
@@ -518,15 +530,23 @@ class ContextUnitTest < Minitest::Test
     registers = {
       my_register: :my_value,
     }
-    super_context = Context.new({}, {}, registers)
+    super_context = Context.new({}, {}, StaticRegisters.new(registers))
+    super_context.registers[:my_register] = :my_alt_value
     subcontext = super_context.new_isolated_subcontext
-    assert_nil subcontext.registers[:my_register]
+    assert_equal :my_value, subcontext.registers[:my_register]
   end
 
   def test_new_isolated_subcontext_inherits_static_registers
-    super_context = Context.build(static_registers: { my_register: :my_value })
+    super_context = Context.build(registers: { my_register: :my_value })
     subcontext = super_context.new_isolated_subcontext
-    assert_equal :my_value, subcontext.static_registers[:my_register]
+    assert_equal :my_value, subcontext.registers[:my_register]
+  end
+
+  def test_new_isolated_subcontext_registers_do_not_pollute_context
+    super_context = Context.build(registers: { my_register: :my_value })
+    subcontext = super_context.new_isolated_subcontext
+    subcontext.registers[:my_register] = :my_alt_value
+    assert_equal :my_value, super_context.registers[:my_register]
   end
 
   def test_new_isolated_subcontext_inherits_filters

test/unit/registers/disabled_tags_unit_test.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class DisabledTagsUnitTest < Minitest::Test
+  include Liquid
+
+  def test_disables_tag_specified
+    register = DisabledTags.new
+    register.disable(%w(foo bar)) do
+      assert_equal true, register.disabled?("foo")
+      assert_equal true, register.disabled?("bar")
+      assert_equal false, register.disabled?("unknown")
+    end
+  end
+
+  def test_disables_nested_tags
+    register = DisabledTags.new
+    register.disable(["foo"]) do
+      register.disable(["foo"]) do
+        assert_equal true, register.disabled?("foo")
+        assert_equal false, register.disabled?("bar")
+      end
+      register.disable(["bar"]) do
+        assert_equal true, register.disabled?("foo")
+        assert_equal true, register.disabled?("bar")
+        register.disable(["foo"]) do
+          assert_equal true, register.disabled?("foo")
+          assert_equal true, register.disabled?("bar")
+        end
+      end
+      assert_equal true, register.disabled?("foo")
+      assert_equal false, register.disabled?("bar")
+    end
+  end
+end

test/unit/static_registers_unit_test.rb

@@ -0,0 +1,248 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class StaticRegistersUnitTest < Minitest::Test
+  include Liquid
+
+  def set
+    static_register = StaticRegisters.new
+    static_register[nil] = true
+    static_register[1] = :one
+    static_register[:one] = "one"
+    static_register["two"] = "three"
+    static_register["two"] = 3
+    static_register[false] = nil
+
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, static_register.registers)
+
+    static_register
+  end
+
+  def test_get
+    static_register = set
+
+    assert_equal true, static_register[nil]
+    assert_equal :one, static_register[1]
+    assert_equal "one", static_register[:one]
+    assert_equal 3, static_register["two"]
+    assert_nil static_register[false]
+    assert_nil static_register["unknown"]
+  end
+
+  def test_delete
+    static_register = set
+
+    assert_equal true, static_register.delete(nil)
+    assert_equal :one, static_register.delete(1)
+    assert_equal "one", static_register.delete(:one)
+    assert_equal 3, static_register.delete("two")
+    assert_nil static_register.delete(false)
+    assert_nil static_register.delete("unknown")
+
+    assert_equal({}, static_register.registers)
+  end
+
+  def test_fetch
+    static_register = set
+
+    assert_equal true, static_register.fetch(nil)
+    assert_equal :one, static_register.fetch(1)
+    assert_equal "one", static_register.fetch(:one)
+    assert_equal 3, static_register.fetch("two")
+    assert_nil static_register.fetch(false)
+    assert_nil static_register.fetch("unknown")
+  end
+
+  def test_fetch_default
+    static_register = StaticRegisters.new
+
+    assert_equal true, static_register.fetch(nil, true)
+    assert_equal :one, static_register.fetch(1, :one)
+    assert_equal "one", static_register.fetch(:one, "one")
+    assert_equal 3, static_register.fetch("two", 3)
+    assert_nil static_register.fetch(false, nil)
+  end
+
+  def test_key
+    static_register = set
+
+    assert_equal true, static_register.key?(nil)
+    assert_equal true, static_register.key?(1)
+    assert_equal true, static_register.key?(:one)
+    assert_equal true, static_register.key?("two")
+    assert_equal true, static_register.key?(false)
+    assert_equal false, static_register.key?("unknown")
+    assert_equal false, static_register.key?(true)
+  end
+
+  def set_with_static
+    static_register = StaticRegisters.new(nil => true, 1 => :one, :one => "one", "two" => 3, false => nil)
+    static_register[nil] = false
+    static_register["two"] = 4
+    static_register[true] = "foo"
+
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, static_register.static)
+    assert_equal({ nil => false, "two" => 4, true => "foo" }, static_register.registers)
+
+    static_register
+  end
+
+  def test_get_with_static
+    static_register = set_with_static
+
+    assert_equal false, static_register[nil]
+    assert_equal :one, static_register[1]
+    assert_equal "one", static_register[:one]
+    assert_equal 4, static_register["two"]
+    assert_equal "foo", static_register[true]
+    assert_nil static_register[false]
+  end
+
+  def test_delete_with_static
+    static_register = set_with_static
+
+    assert_equal false, static_register.delete(nil)
+    assert_equal 4, static_register.delete("two")
+    assert_equal "foo", static_register.delete(true)
+    assert_nil static_register.delete("unknown")
+    assert_nil static_register.delete(:one)
+
+    assert_equal({}, static_register.registers)
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, static_register.static)
+  end
+
+  def test_fetch_with_static
+    static_register = set_with_static
+
+    assert_equal false, static_register.fetch(nil)
+    assert_equal :one, static_register.fetch(1)
+    assert_equal "one", static_register.fetch(:one)
+    assert_equal 4, static_register.fetch("two")
+    assert_equal "foo", static_register.fetch(true)
+    assert_nil static_register.fetch(false)
+  end
+
+  def test_key_with_static
+    static_register = set_with_static
+
+    assert_equal true, static_register.key?(nil)
+    assert_equal true, static_register.key?(1)
+    assert_equal true, static_register.key?(:one)
+    assert_equal true, static_register.key?("two")
+    assert_equal true, static_register.key?(false)
+    assert_equal false, static_register.key?("unknown")
+    assert_equal true, static_register.key?(true)
+  end
+
+  def test_static_register_can_be_frozen
+    static_register = set_with_static
+
+    static = static_register.static.freeze
+
+    assert_raises(RuntimeError) do
+      static["two"] = "foo"
+    end
+
+    assert_raises(RuntimeError) do
+      static["unknown"] = "foo"
+    end
+
+    assert_raises(RuntimeError) do
+      static.delete("two")
+    end
+  end
+
+  def test_new_static_retains_static
+    static_register = StaticRegisters.new(nil => true, 1 => :one, :one => "one", "two" => 3, false => nil)
+    static_register["one"] = 1
+    static_register["two"] = 2
+    static_register["three"] = 3
+
+    new_register = StaticRegisters.new(static_register)
+    assert_equal({}, new_register.registers)
+
+    new_register["one"] = 4
+    new_register["two"] = 5
+    new_register["three"] = 6
+
+    newest_register = StaticRegisters.new(new_register)
+    assert_equal({}, newest_register.registers)
+
+    newest_register["one"] = 7
+    newest_register["two"] = 8
+    newest_register["three"] = 9
+
+    assert_equal({ "one" => 1, "two" => 2, "three" => 3 }, static_register.registers)
+    assert_equal({ "one" => 4, "two" => 5, "three" => 6 }, new_register.registers)
+    assert_equal({ "one" => 7, "two" => 8, "three" => 9 }, newest_register.registers)
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, static_register.static)
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, new_register.static)
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, newest_register.static)
+  end
+
+  def test_multiple_instances_are_unique
+    static_register = StaticRegisters.new(nil => true, 1 => :one, :one => "one", "two" => 3, false => nil)
+    static_register["one"] = 1
+    static_register["two"] = 2
+    static_register["three"] = 3
+
+    new_register = StaticRegisters.new(foo: :bar)
+    assert_equal({}, new_register.registers)
+
+    new_register["one"] = 4
+    new_register["two"] = 5
+    new_register["three"] = 6
+
+    newest_register = StaticRegisters.new(bar: :foo)
+    assert_equal({}, newest_register.registers)
+
+    newest_register["one"] = 7
+    newest_register["two"] = 8
+    newest_register["three"] = 9
+
+    assert_equal({ "one" => 1, "two" => 2, "three" => 3 }, static_register.registers)
+    assert_equal({ "one" => 4, "two" => 5, "three" => 6 }, new_register.registers)
+    assert_equal({ "one" => 7, "two" => 8, "three" => 9 }, newest_register.registers)
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, static_register.static)
+    assert_equal({ foo: :bar }, new_register.static)
+    assert_equal({ bar: :foo }, newest_register.static)
+  end
+
+  def test_can_update_static_directly_and_updates_all_instances
+    static_register = StaticRegisters.new(nil => true, 1 => :one, :one => "one", "two" => 3, false => nil)
+    static_register["one"] = 1
+    static_register["two"] = 2
+    static_register["three"] = 3
+
+    new_register = StaticRegisters.new(static_register)
+    assert_equal({}, new_register.registers)
+
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, static_register.static)
+
+    new_register["one"] = 4
+    new_register["two"] = 5
+    new_register["three"] = 6
+    new_register.static["four"] = 10
+
+    newest_register = StaticRegisters.new(new_register)
+    assert_equal({}, newest_register.registers)
+
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil, "four" => 10 }, new_register.static)
+
+    newest_register["one"] = 7
+    newest_register["two"] = 8
+    newest_register["three"] = 9
+    new_register.static["four"] = 5
+    new_register.static["five"] = 15
+
+    assert_equal({ "one" => 1, "two" => 2, "three" => 3 }, static_register.registers)
+    assert_equal({ "one" => 4, "two" => 5, "three" => 6 }, new_register.registers)
+    assert_equal({ "one" => 7, "two" => 8, "three" => 9 }, newest_register.registers)
+
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil, "four" => 5, "five" => 15 }, newest_register.static)
+
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil, "four" => 5, "five" => 15 }, static_register.static)
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil, "four" => 5, "five" => 15 }, new_register.static)
+  end
+end

test/unit/tokenizer_unit_test.rb

@@ -35,7 +35,7 @@ class TokenizerTest < Minitest::Test
   def tokenize(source)
     tokenizer = Liquid::Tokenizer.new(source)
     tokens = []
-    while t = tokenizer.shift
+    while (t = tokenizer.shift)
       tokens << t
     end
     tokens