Expand usage tracking

* Use `Regexp#match?` when `MatchData` is not used

* Add `TargetRubyVersion: 2.4` to RuboCop config

.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.
@@ -76,26 +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: 119
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: always, never
-Style/FrozenStringLiteralComment:
-  Enabled: false
-
-# 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:

Gemfile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 git_source(:github) do |repo_name|
   "https://github.com/#{repo_name}.git"

Rakefile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rake'
 require 'rake/testtask'
 $LOAD_PATH.unshift(File.expand_path("../lib", __FILE__))

example/server/example_servlet.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ProductsFilter
   def price(integer)
     format("$%.2d USD", integer / 100.0)

example/server/liquid_servlet.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class LiquidServlet < WEBrick::HTTPServlet::AbstractServlet
   def do_GET(req, res)
     handle(:get, req, res)

example/server/server.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'webrick'
 require 'rexml/document'
 

lib/liquid.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Copyright (c) 2005 Tobias Luetke
 #
 # Permission is hereby granted, free of charge, to any person obtaining
@@ -21,10 +23,10 @@
 
 module Liquid
   FilterSeparator             = /\|/
-  ArgumentSeparator           = ','.freeze
+  ArgumentSeparator           = ','
-  FilterArgumentSeparator     = ':'.freeze
+  FilterArgumentSeparator     = ':'
-  VariableAttributeSeparator  = '.'.freeze
+  VariableAttributeSeparator  = '.'
-  WhitespaceControl           = '-'.freeze
+  WhitespaceControl           = '-'
   TagStart                    = /\{\%/
   TagEnd                      = /\%\}/
   VariableSignature           = /\(?[\w\-\.\[\]]\)?/
@@ -76,6 +78,7 @@ require 'liquid/tokenizer'
 require 'liquid/parse_context'
 require 'liquid/partial_cache'
 require 'liquid/usage'
+require 'liquid/static_registers'
 
 # Load all the tags of the standard library
 #

lib/liquid/block.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Block < Tag
     MAX_DEPTH = 100
@@ -27,16 +29,16 @@ module Liquid
     end
 
     def unknown_tag(tag, _params, _tokens)
-      if tag == 'else'.freeze
+      if tag == 'else'
-        raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_else".freeze,
+        raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_else",
           block_name: block_name)
-      elsif tag.start_with?('end'.freeze)
+      elsif tag.start_with?('end')
-        raise SyntaxError, parse_context.locale.t("errors.syntax.invalid_delimiter".freeze,
+        raise SyntaxError, parse_context.locale.t("errors.syntax.invalid_delimiter",
           tag: tag,
           block_name: block_name,
           block_delimiter: block_delimiter)
       else
-        raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag".freeze, tag: tag)
+        raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag", tag: tag)
       end
     end
 
@@ -52,7 +54,7 @@ module Liquid
 
     def parse_body(body, tokens)
       if parse_context.depth >= MAX_DEPTH
-        raise StackLevelError, "Nesting too deep".freeze
+        raise StackLevelError, "Nesting too deep"
       end
       parse_context.depth += 1
       begin
@@ -61,7 +63,7 @@ module Liquid
 
           return false if end_tag_name == block_delimiter
           unless end_tag_name
-            raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed".freeze, block_name: block_name)
+            raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)
           end
 
           # this tag is not registered with the system

lib/liquid/block_body.rb

@@ -1,11 +1,13 @@
+# frozen_string_literal: true
+
 module Liquid
   class BlockBody
     LiquidTagToken = /\A\s*(\w+)\s*(.*?)\z/o
     FullToken = /\A#{TagStart}#{WhitespaceControl}?(\s*)(\w+)(\s*)(.*?)#{WhitespaceControl}?#{TagEnd}\z/om
     ContentOfVariable = /\A#{VariableStart}#{WhitespaceControl}?(.*?)#{WhitespaceControl}?#{VariableEnd}\z/om
     WhitespaceOrNothing = /\A\s*\z/
-    TAGSTART = "{%".freeze
+    TAGSTART = "{%"
-    VARSTART = "{{".freeze
+    VARSTART = "{{"
 
     attr_reader :nodelist
 
@@ -25,7 +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
@@ -34,7 +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
@@ -50,7 +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)
@@ -64,15 +66,15 @@ module Liquid
           if parse_context.line_number
             # newlines inside the tag should increase the line number,
             # particularly important for multiline {% liquid %} tags
-            parse_context.line_number += Regexp.last_match(1).count("\n".freeze) + Regexp.last_match(3).count("\n".freeze)
+            parse_context.line_number += Regexp.last_match(1).count("\n") + Regexp.last_match(3).count("\n")
           end
 
-          if tag_name == 'liquid'.freeze
+          if tag_name == 'liquid'
             liquid_tag_tokenizer = Tokenizer.new(markup, line_number: parse_context.line_number, for_liquid_tag: true)
             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
@@ -113,14 +115,14 @@ module Liquid
     end
 
     def render(context)
-      render_to_output_buffer(context, '')
+      render_to_output_buffer(context, +'')
     end
 
     def render_to_output_buffer(context, output)
       context.resource_limits.render_score += @nodelist.length
 
       idx = 0
-      while node = @nodelist[idx]
+      while (node = @nodelist[idx])
         previous_output_size = output.bytesize
 
         case node
@@ -129,7 +131,7 @@ module Liquid
         when Variable
           render_node(context, output, node)
         when Block
-          render_node(context, node.blank? ? '' : output, node)
+          render_node(context, node.blank? ? +'' : output, node)
           break if context.interrupt? # might have happened in a for-block
         when Continue, Break
           # If we get an Interrupt that means the block must stop processing. An
@@ -163,7 +165,7 @@ module Liquid
     def raise_if_resource_limits_reached(context, length)
       context.resource_limits.render_length += length
       return unless context.resource_limits.reached?
-      raise MemoryError, "Memory limits exceeded".freeze
+      raise MemoryError, "Memory limits exceeded"
     end
 
     def create_variable(token, parse_context)
@@ -175,11 +177,11 @@ module Liquid
     end
 
     def raise_missing_tag_terminator(token, parse_context)
-      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_termination".freeze, token: token, tag_end: TagEnd.inspect)
+      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_termination", token: token, tag_end: TagEnd.inspect)
     end
 
     def raise_missing_variable_terminator(token, parse_context)
-      raise SyntaxError, parse_context.locale.t("errors.syntax.variable_termination".freeze, token: token, tag_end: VariableEnd.inspect)
+      raise SyntaxError, parse_context.locale.t("errors.syntax.variable_termination", token: token, tag_end: VariableEnd.inspect)
     end
 
     def registered_tags

lib/liquid/condition.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Container for liquid nodes which conveniently wraps decision making logic
   #
@@ -8,14 +10,14 @@ module Liquid
   #
   class Condition #:nodoc:
     @@operators = {
-      '=='.freeze => ->(cond, left, right) {  cond.send(:equal_variables, left, right) },
+      '==' => ->(cond, left, right) {  cond.send(:equal_variables, left, right) },
-      '!='.freeze => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
+      '!=' => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
-      '<>'.freeze => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
+      '<>' => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
-      '<'.freeze => :<,
+      '<' => :<,
-      '>'.freeze => :>,
+      '>' => :>,
-      '>='.freeze => :>=,
+      '>=' => :>=,
-      '<='.freeze => :<=,
+      '<=' => :<=,
-      'contains'.freeze => lambda do |_cond, left, right|
+      'contains' => lambda do |_cond, left, right|
         if left && right && left.respond_to?(:include?)
           right = right.to_s if left.is_a?(String)
           left.include?(right)
@@ -78,7 +80,7 @@ module Liquid
     end
 
     def inspect
-      "#<Condition #{[@left, @operator, @right].compact.join(' '.freeze)}>"
+      "#<Condition #{[@left, @operator, @right].compact.join(' ')}>"
     end
 
     protected

lib/liquid/context.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Context keeps the variable stack and resolves variables, as well as keywords
   #
@@ -16,29 +18,32 @@ 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.is_a?(Array) ? environments : [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
       @resource_limits     = resource_limits || ResourceLimits.new(Template.default_resource_limits)
       @base_scope_depth    = 0
-      @interrupts          = []
+      squash_instance_assigns_with_environments
-      @filters             = []
-      @global_filter       = nil
 
       self.exception_renderer = Template.default_exception_renderer
       if rethrow_errors
         self.exception_renderer = ->(_e) { raise }
       end
+
+      @interrupts = []
+      @filters = []
+      @global_filter = nil
     end
     # rubocop:enable Metrics/ParameterLists
 
@@ -131,7 +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
@@ -214,12 +219,16 @@ module Liquid
     def try_variable_find_in_environments(key, raise_on_not_found:)
       @environments.each do |environment|
         found_variable = lookup_and_evaluate(environment, key, raise_on_not_found: raise_on_not_found)
+        Usage.increment("environment_has_a_default_proc") if environment.respond_to?(:default_proc) && environment.default_proc
+        Usage.increment("environment_has_key_but_is_nil") if environment.respond_to?(:key?) && environment.key?(key) && found_variable.nil?
         if !found_variable.nil? || @strict_variables && raise_on_not_found
           return found_variable
         end
       end
       @static_environments.each do |environment|
         found_variable = lookup_and_evaluate(environment, key, raise_on_not_found: raise_on_not_found)
+        Usage.increment("static_environment_has_a_default_proc") if environment.respond_to?(:default_proc) && environment.default_proc
+        Usage.increment("static_environment_has_key_but_is_nil") if environment.respond_to?(:key?) && environment.key?(key) && found_variable.nil?
         if !found_variable.nil? || @strict_variables && raise_on_not_found
           return found_variable
         end
@@ -228,7 +237,7 @@ module Liquid
     end
 
     def check_overflow
-      raise StackLevelError, "Nesting too deep".freeze if overflow?
+      raise StackLevelError, "Nesting too deep" if overflow?
     end
 
     def overflow?
@@ -241,5 +250,16 @@ module Liquid
     rescue Liquid::InternalError => exc
       exc
     end
+
+    def squash_instance_assigns_with_environments
+      @scopes.last.each_key do |k|
+        @environments.each do |env|
+          if env.key?(k)
+            scopes.last[k] = lookup_and_evaluate(env, k)
+            break
+          end
+        end
+      end
+    end # squash_instance_assigns_with_environments
   end # Context
 end # Liquid

lib/liquid/document.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Document < BlockBody
     def self.parse(tokens, parse_context)
@@ -17,10 +19,10 @@ module Liquid
 
     def unknown_tag(tag, parse_context)
       case tag
-      when 'else'.freeze, 'end'.freeze
+      when 'else', 'end'
-        raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_outer_tag".freeze, tag: tag)
+        raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_outer_tag", tag: tag)
       else
-        raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag".freeze, tag: tag)
+        raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag", tag: tag)
       end
     end
   end

lib/liquid/drop.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'set'
 
 module Liquid
@@ -67,7 +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/errors.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Error < ::StandardError
     attr_accessor :line_number
@@ -5,7 +7,7 @@ module Liquid
     attr_accessor :markup_context
 
     def to_s(with_prefix = true)
-      str = ""
+      str = +""
       str << message_prefix if with_prefix
       str << super()
 
@@ -20,7 +22,7 @@ module Liquid
     private
 
     def message_prefix
-      str = ""
+      str = +""
       str << if is_a?(SyntaxError)
         "Liquid syntax error"
       else

lib/liquid/expression.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Expression
     class MethodLiteral
@@ -14,11 +16,11 @@ module Liquid
     end
 
     LITERALS = {
-      nil => nil, 'nil'.freeze => nil, 'null'.freeze => nil, ''.freeze => nil,
+      nil => nil, 'nil' => nil, 'null' => nil, '' => nil,
-      'true'.freeze => true,
+      'true' => true,
-      'false'.freeze => false,
+      'false' => false,
-      'blank'.freeze => MethodLiteral.new(:blank?, '').freeze,
+      'blank' => MethodLiteral.new(:blank?, '').freeze,
-      'empty'.freeze => MethodLiteral.new(:empty?, '').freeze
+      'empty' => MethodLiteral.new(:empty?, '').freeze
     }.freeze
 
     SINGLE_QUOTED_STRING = /\A'(.*)'\z/m

lib/liquid/extensions.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'time'
 require 'date'
 

lib/liquid/file_system.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # A Liquid file system is a way to let your templates retrieve other templates for use with the include tag.
   #
@@ -44,7 +46,7 @@ module Liquid
   class LocalFileSystem
     attr_accessor :root
 
-    def initialize(root, pattern = "_%s.liquid".freeze)
+    def initialize(root, pattern = "_%s.liquid")
       @root = root
       @pattern = pattern
     end
@@ -57,9 +59,9 @@ 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?('/'.freeze)
+      full_path = if template_path.include?('/')
         File.join(root, File.dirname(template_path), @pattern % File.basename(template_path))
       else
         File.join(root, @pattern % template_path)

lib/liquid/forloop_drop.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class ForloopDrop < Drop
     def initialize(name, length, parentloop)

lib/liquid/i18n.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'yaml'
 
 module Liquid
@@ -31,7 +33,7 @@ module Liquid
     end
 
     def deep_fetch_translation(name)
-      name.split('.'.freeze).reduce(locale) do |level, cur|
+      name.split('.').reduce(locale) do |level, cur|
         level[cur] || raise(TranslationError, "Translation for #{name} does not exist in locale #{path}")
       end
     end

lib/liquid/interrupts.rb

@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 module Liquid
   # An interrupt is any command that breaks processing of a block (ex: a for loop).
   class Interrupt
     attr_reader :message
 
     def initialize(message = nil)
-      @message = message || "interrupt".freeze
+      @message = message || "interrupt"
     end
   end
 

lib/liquid/lexer.rb

@@ -1,17 +1,19 @@
+# frozen_string_literal: true
+
 require "strscan"
 module Liquid
   class Lexer
     SPECIALS = {
-      '|'.freeze => :pipe,
+      '|' => :pipe,
-      '.'.freeze => :dot,
+      '.' => :dot,
-      ':'.freeze => :colon,
+      ':' => :colon,
-      ','.freeze => :comma,
+      ',' => :comma,
-      '['.freeze => :open_square,
+      '[' => :open_square,
-      ']'.freeze => :close_square,
+      ']' => :close_square,
-      '('.freeze => :open_round,
+      '(' => :open_round,
-      ')'.freeze => :close_round,
+      ')' => :close_round,
-      '?'.freeze => :question,
+      '?' => :question,
-      '-'.freeze => :dash,
+      '-' => :dash,
     }.freeze
     IDENTIFIER = /[a-zA-Z_][\w-]*\??/
     SINGLE_STRING_LITERAL = /'[^\']*'/
@@ -31,15 +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/parse_context.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class ParseContext
     attr_accessor :locale, :line_number, :trim_whitespace, :depth
@@ -19,7 +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/parser.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Parser
     def initialize(input)
@@ -66,10 +68,10 @@ module Liquid
     end
 
     def argument
-      str = ""
+      str = +""
       # might be a keyword argument (identifier: expression)
       if look(:id) && look(:colon, 1)
-        str << consume << consume << ' '.freeze
+        str << consume << consume << ' '
       end
 
       str << expression

lib/liquid/parser_switching.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   module ParserSwitching
     def parse_with_selected_parser(markup)

lib/liquid/partial_cache.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class PartialCache
     def self.load(template_name, context:, parse_context:)

lib/liquid/profiler.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'liquid/profiler/hooks'
 
 module Liquid

lib/liquid/profiler/hooks.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class BlockBody
     def render_node_with_profiling(context, output, node)

lib/liquid/range_lookup.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class RangeLookup
     def self.parse(start_markup, end_markup)

lib/liquid/resource_limits.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class ResourceLimits
     attr_accessor :render_length, :render_score, :assign_score,

lib/liquid/standardfilters.rb

@@ -1,14 +1,16 @@
+# frozen_string_literal: true
+
 require 'cgi'
 require 'bigdecimal'
 
 module Liquid
   module StandardFilters
     HTML_ESCAPE = {
-      '&'.freeze => '&'.freeze,
+      '&' => '&',
-      '>'.freeze => '>'.freeze,
+      '>' => '>',
-      '<'.freeze => '&lt;'.freeze,
+      '<' => '&lt;',
-      '"'.freeze => '&quot;'.freeze,
+      '"' => '&quot;',
-      "'".freeze => '&#39;'.freeze,
+      "'" => '&#39;',
     }.freeze
     HTML_ESCAPE_ONCE_REGEXP = /["><']|&(?!([a-zA-Z]+|(#\d+));)/
     STRIP_HTML_BLOCKS = Regexp.union(
@@ -72,7 +74,7 @@ module Liquid
     end
 
     # Truncate a string down to x characters
-    def truncate(input, length = 50, truncate_string = "...".freeze)
+    def truncate(input, length = 50, truncate_string = "...")
       return if input.nil?
       input_str = input.to_s
       length = Utils.to_integer(length)
@@ -82,13 +84,13 @@ module Liquid
       input_str.length > length ? input_str[0...l].concat(truncate_string_str) : input_str
     end
 
-    def truncatewords(input, words = 15, truncate_string = "...".freeze)
+    def truncatewords(input, words = 15, truncate_string = "...")
       return if input.nil?
       wordlist = input.to_s.split
       words = Utils.to_integer(words)
       l = words - 1
       l = 0 if l < 0
-      wordlist.length > l ? wordlist[0..l].join(" ".freeze).concat(truncate_string.to_s) : input
+      wordlist.length > l ? wordlist[0..l].join(" ").concat(truncate_string.to_s) : input
     end
 
     # Split input string into an array of substrings separated by given pattern.
@@ -113,7 +115,7 @@ module Liquid
     end
 
     def strip_html(input)
-      empty = ''.freeze
+      empty = ''
       result = input.to_s.gsub(STRIP_HTML_BLOCKS, empty)
       result.gsub!(STRIP_HTML_TAGS, empty)
       result
@@ -121,11 +123,11 @@ module Liquid
 
     # Remove all newlines from the string
     def strip_newlines(input)
-      input.to_s.gsub(/\r?\n/, ''.freeze)
+      input.to_s.gsub(/\r?\n/, '')
     end
 
     # Join elements of the array with certain character between them
-    def join(input, glue = ' '.freeze)
+    def join(input, glue = ' ')
       InputIterator.new(input).join(glue)
     end
 
@@ -220,7 +222,7 @@ module Liquid
       InputIterator.new(input).map do |e|
         e = e.call if e.is_a?(Proc)
 
-        if property == "to_liquid".freeze
+        if property == "to_liquid"
           e
         elsif e.respond_to?(:[])
           r = e[property]
@@ -250,23 +252,23 @@ module Liquid
     end
 
     # Replace occurrences of a string with another
-    def replace(input, string, replacement = ''.freeze)
+    def replace(input, string, replacement = '')
       input.to_s.gsub(string.to_s, replacement.to_s)
     end
 
     # Replace the first occurrences of a string with another
-    def replace_first(input, string, replacement = ''.freeze)
+    def replace_first(input, string, replacement = '')
       input.to_s.sub(string.to_s, replacement.to_s)
     end
 
     # remove a substring
     def remove(input, string)
-      input.to_s.gsub(string.to_s, ''.freeze)
+      input.to_s.gsub(string.to_s, '')
     end
 
     # remove the first occurrences of a substring
     def remove_first(input, string)
-      input.to_s.sub(string.to_s, ''.freeze)
+      input.to_s.sub(string.to_s, '')
     end
 
     # add one string to another
@@ -288,7 +290,7 @@ module Liquid
 
     # Add <br /> tags in front of all newlines in input string
     def newline_to_br(input)
-      input.to_s.gsub(/\n/, "<br />\n".freeze)
+      input.to_s.gsub(/\n/, "<br />\n")
     end
 
     # Reformat a date using Ruby's core Time#strftime( string ) -> string
@@ -325,7 +327,7 @@ 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
@@ -419,9 +421,8 @@ module Liquid
       result.is_a?(BigDecimal) ? result.to_f : result
     end
 
-    def default(input, default_value = ''.freeze)
+    def default(input, default_value = '')
       if !input || input.respond_to?(:empty?) && input.empty?
-        Usage.increment("default_filter_received_false_value") if input == false # See https://github.com/Shopify/liquid/issues/1127
         default_value
       else
         input

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/strainer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'set'
 
 module Liquid

lib/liquid/tablerowloop_drop.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class TablerowloopDrop < Drop
     def initialize(length, cols)

lib/liquid/tag.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Tag
     attr_reader :nodelist, :tag_name, :line_number, :parse_context
@@ -33,7 +35,7 @@ module Liquid
     end
 
     def render(_context)
-      ''.freeze
+      ''
     end
 
     # For backwards compatibility with custom tags. In a future release, the semantics

lib/liquid/tags/assign.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Assign sets a variable in your template.
   #
@@ -11,7 +13,7 @@ module Liquid
     Syntax = /(#{VariableSignature}+)\s*=\s*(.*)\s*/om
 
     def self.syntax_error_translation_key
-      "errors.syntax.assign".freeze
+      "errors.syntax.assign"
     end
 
     attr_reader :to, :from
@@ -59,5 +61,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('assign'.freeze, Assign)
+  Template.register_tag('assign', Assign)
 end

lib/liquid/tags/break.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Break tag to be used to break out of a for loop.
   #
@@ -14,5 +16,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('break'.freeze, Break)
+  Template.register_tag('break', Break)
 end

lib/liquid/tags/capture.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Capture stores the result of a block into a variable without rendering it inplace.
   #
@@ -35,5 +37,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('capture'.freeze, Capture)
+  Template.register_tag('capture', Capture)
 end

lib/liquid/tags/case.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Case < Block
     Syntax     = /(#{QuotedFragment})/o
@@ -12,7 +14,7 @@ module Liquid
       if markup =~ Syntax
         @left = Expression.parse(Regexp.last_match(1))
       else
-        raise SyntaxError, options[:locale].t("errors.syntax.case".freeze)
+        raise SyntaxError, options[:locale].t("errors.syntax.case")
       end
     end
 
@@ -27,9 +29,9 @@ module Liquid
 
     def unknown_tag(tag, markup, tokens)
       case tag
-      when 'when'.freeze
+      when 'when'
         record_when_condition(markup)
-      when 'else'.freeze
+      when 'else'
         record_else_condition(markup)
       else
         super
@@ -58,12 +60,12 @@ module Liquid
 
       while markup
         unless markup =~ WhenSyntax
-          raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_when".freeze)
+          raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_when")
         end
 
         markup = Regexp.last_match(2)
 
-        block = Condition.new(@left, '=='.freeze, Expression.parse(Regexp.last_match(1)))
+        block = Condition.new(@left, '==', Expression.parse(Regexp.last_match(1)))
         block.attach(body)
         @blocks << block
       end
@@ -71,7 +73,7 @@ module Liquid
 
     def record_else_condition(markup)
       unless markup.strip.empty?
-        raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_else".freeze)
+        raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_else")
       end
 
       block = ElseCondition.new
@@ -86,5 +88,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('case'.freeze, Case)
+  Template.register_tag('case', Case)
 end

lib/liquid/tags/comment.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Comment < Block
     def render_to_output_buffer(_context, output)
@@ -12,5 +14,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('comment'.freeze, Comment)
+  Template.register_tag('comment', Comment)
 end

lib/liquid/tags/continue.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Continue tag to be used to break out of a for loop.
   #
@@ -14,5 +16,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('continue'.freeze, Continue)
+  Template.register_tag('continue', Continue)
 end

lib/liquid/tags/cycle.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Cycle is usually used within a loop to alternate between values, like colors or DOM classes.
   #
@@ -27,7 +29,7 @@ module Liquid
         @variables = variables_from_string(markup)
         @name = @variables.to_s
       else
-        raise SyntaxError, options[:locale].t("errors.syntax.cycle".freeze)
+        raise SyntaxError, options[:locale].t("errors.syntax.cycle")
       end
     end
 

lib/liquid/tags/decrement.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # decrement is used in a place where one needs to insert a counter
   #     into a template, and needs the counter to survive across
@@ -32,5 +34,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('decrement'.freeze, Decrement)
+  Template.register_tag('decrement', Decrement)
 end

lib/liquid/tags/echo.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Echo outputs an expression
   #
@@ -16,9 +18,9 @@ module Liquid
     end
 
     def render(context)
-      @variable.render_to_output_buffer(context, '')
+      @variable.render_to_output_buffer(context, +'')
     end
   end
 
-  Template.register_tag('echo'.freeze, Echo)
+  Template.register_tag('echo', Echo)
 end

lib/liquid/tags/for.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # "For" iterates over an array or collection.
   # Several useful variables are available to you within the loop.
@@ -66,7 +68,7 @@ module Liquid
     end
 
     def unknown_tag(tag, markup, tokens)
-      return super unless tag == 'else'.freeze
+      return super unless tag == 'else'
       @else_block = BlockBody.new
     end
 
@@ -95,22 +97,22 @@ module Liquid
           set_attribute(key, value)
         end
       else
-        raise SyntaxError, options[:locale].t("errors.syntax.for".freeze)
+        raise SyntaxError, options[:locale].t("errors.syntax.for")
       end
     end
 
     def strict_parse(markup)
       p = Parser.new(markup)
       @variable_name = p.consume(:id)
-      raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_in".freeze) unless p.id?('in'.freeze)
+      raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_in") unless p.id?('in')
       collection_name = p.expression
       @name = "#{@variable_name}-#{collection_name}"
       @collection_name = Expression.parse(collection_name)
-      @reversed = p.id?('reversed'.freeze)
+      @reversed = p.id?('reversed')
 
       while p.look(:id) && p.look(:colon, 1)
-        unless attribute = p.id?('limit'.freeze) || p.id?('offset'.freeze)
+        unless (attribute = p.id?('limit') || p.id?('offset'))
-          raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_attribute".freeze)
+          raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_attribute")
         end
         p.consume
         set_attribute(attribute, p.expression)
@@ -162,7 +164,7 @@ module Liquid
         for_stack.push(loop_vars)
 
         begin
-          context['forloop'.freeze] = loop_vars
+          context['forloop'] = loop_vars
 
           segment.each do |item|
             context[@variable_name] = item
@@ -185,13 +187,13 @@ module Liquid
 
     def set_attribute(key, expr)
       case key
-      when 'offset'.freeze
+      when 'offset'
-        @from = if expr == 'continue'.freeze
+        @from = if expr == 'continue'
           :continue
         else
           Expression.parse(expr)
         end
-      when 'limit'.freeze
+      when 'limit'
         @limit = Expression.parse(expr)
       end
     end
@@ -211,5 +213,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('for'.freeze, For)
+  Template.register_tag('for', For)
 end

lib/liquid/tags/if.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # If is the conditional block
   #
@@ -19,7 +21,7 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
       @blocks = []
-      push_block('if'.freeze, markup)
+      push_block('if', markup)
     end
 
     def nodelist
@@ -32,7 +34,7 @@ module Liquid
     end
 
     def unknown_tag(tag, markup, tokens)
-      if ['elsif'.freeze, 'else'.freeze].include?(tag)
+      if ['elsif', 'else'].include?(tag)
         push_block(tag, markup)
       else
         super
@@ -52,7 +54,7 @@ module Liquid
     private
 
     def push_block(tag, markup)
-      block = if tag == 'else'.freeze
+      block = if tag == 'else'
         ElseCondition.new
       else
         parse_with_selected_parser(markup)
@@ -64,17 +66,17 @@ module Liquid
 
     def lax_parse(markup)
       expressions = markup.scan(ExpressionsAndOperators)
-      raise SyntaxError, options[:locale].t("errors.syntax.if".freeze) unless expressions.pop =~ Syntax
+      raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop =~ Syntax
 
       condition = Condition.new(Expression.parse(Regexp.last_match(1)), Regexp.last_match(2), Expression.parse(Regexp.last_match(3)))
 
       until expressions.empty?
         operator = expressions.pop.to_s.strip
 
-        raise SyntaxError, options[:locale].t("errors.syntax.if".freeze) unless expressions.pop.to_s =~ Syntax
+        raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop.to_s =~ Syntax
 
         new_condition = Condition.new(Expression.parse(Regexp.last_match(1)), Regexp.last_match(2), Expression.parse(Regexp.last_match(3)))
-        raise SyntaxError, options[:locale].t("errors.syntax.if".freeze) unless BOOLEAN_OPERATORS.include?(operator)
+        raise SyntaxError, options[:locale].t("errors.syntax.if") unless BOOLEAN_OPERATORS.include?(operator)
         new_condition.send(operator, condition)
         condition = new_condition
       end
@@ -92,7 +94,7 @@ module Liquid
     def parse_binary_comparisons(p)
       condition = parse_comparison(p)
       first_condition = condition
-      while op = (p.id?('and'.freeze) || p.id?('or'.freeze))
+      while (op = (p.id?('and') || p.id?('or')))
         child_condition = parse_comparison(p)
         condition.send(op, child_condition)
         condition = child_condition
@@ -102,7 +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
@@ -117,5 +119,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('if'.freeze, If)
+  Template.register_tag('if', If)
 end

lib/liquid/tags/ifchanged.rb

@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 module Liquid
   class Ifchanged < Block
     def render_to_output_buffer(context, output)
-      block_output = ''
+      block_output = +''
       super(context, block_output)
 
       if block_output != context.registers[:ifchanged]
@@ -13,5 +15,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('ifchanged'.freeze, Ifchanged)
+  Template.register_tag('ifchanged', Ifchanged)
 end

lib/liquid/tags/include.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Include allows templates to relate with other templates
   #
@@ -35,7 +37,7 @@ module Liquid
         end
 
       else
-        raise SyntaxError, options[:locale].t("errors.syntax.include".freeze)
+        raise SyntaxError, options[:locale].t("errors.syntax.include")
       end
     end
 
@@ -52,7 +54,7 @@ module Liquid
         parse_context: parse_context
       )
 
-      context_variable_name = template_name.split('/'.freeze).last
+      context_variable_name = template_name.split('/').last
 
       variable = if @variable_name_expr
         context.evaluate(@variable_name_expr)
@@ -101,5 +103,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('include'.freeze, Include)
+  Template.register_tag('include', Include)
 end

lib/liquid/tags/increment.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # increment is used in a place where one needs to insert a counter
   #     into a template, and needs the counter to survive across
@@ -29,5 +31,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('increment'.freeze, Increment)
+  Template.register_tag('increment', Increment)
 end

lib/liquid/tags/raw.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Raw < Block
     Syntax = /\A\s*\z/
@@ -10,16 +12,16 @@ module Liquid
     end
 
     def parse(tokens)
-      @body = ''
+      @body = +''
-      while token = tokens.shift
+      while (token = tokens.shift)
         if token =~ FullTokenPossiblyInvalid
-          @body << Regexp.last_match(1) if Regexp.last_match(1) != "".freeze
+          @body << Regexp.last_match(1) if Regexp.last_match(1) != ""
           return if block_delimiter == Regexp.last_match(2)
         end
         @body << token unless token.empty?
       end
 
-      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed".freeze, block_name: block_name)
+      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)
     end
 
     def render_to_output_buffer(_context, output)
@@ -38,11 +40,11 @@ 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".freeze, tag: tag_name)
+        raise SyntaxError, parse_context.locale.t("errors.syntax.tag_unexpected_args", tag: tag_name)
       end
     end
   end
 
-  Template.register_tag('raw'.freeze, Raw)
+  Template.register_tag('raw', Raw)
 end

lib/liquid/tags/render.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Render < Tag
     SYNTAX = /(#{QuotedString})#{QuotedFragment}*/o
@@ -7,7 +9,7 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
 
-      raise SyntaxError, options[:locale].t("errors.syntax.render".freeze) unless markup =~ SYNTAX
+      raise SyntaxError, options[:locale].t("errors.syntax.render") unless markup =~ SYNTAX
 
       template_name = Regexp.last_match(1)
 
@@ -50,5 +52,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('render'.freeze, Render)
+  Template.register_tag('render', Render)
 end

lib/liquid/tags/table_row.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class TableRow < Block
     Syntax = /(\w+)\s+in\s+(#{QuotedFragment}+)/o
@@ -14,26 +16,26 @@ module Liquid
           @attributes[key] = Expression.parse(value)
         end
       else
-        raise SyntaxError, options[:locale].t("errors.syntax.table_row".freeze)
+        raise SyntaxError, options[:locale].t("errors.syntax.table_row")
       end
     end
 
     def render_to_output_buffer(context, output)
-      (collection = context.evaluate(@collection_name)) || (return ''.freeze)
+      (collection = context.evaluate(@collection_name)) || (return '')
 
-      from = @attributes.key?('offset'.freeze) ? context.evaluate(@attributes['offset'.freeze]).to_i : 0
+      from = @attributes.key?('offset') ? context.evaluate(@attributes['offset']).to_i : 0
-      to = @attributes.key?('limit'.freeze) ? from + context.evaluate(@attributes['limit'.freeze]).to_i : nil
+      to = @attributes.key?('limit') ? from + context.evaluate(@attributes['limit']).to_i : nil
 
       collection = Utils.slice_collection(collection, from, to)
 
       length = collection.length
 
-      cols = context.evaluate(@attributes['cols'.freeze]).to_i
+      cols = context.evaluate(@attributes['cols']).to_i
 
       output << "<tr class=\"row1\">\n"
       context.stack do
         tablerowloop = Liquid::TablerowloopDrop.new(length, cols)
-        context['tablerowloop'.freeze] = tablerowloop
+        context['tablerowloop'] = tablerowloop
 
         collection.each do |item|
           context[@variable_name] = item
@@ -61,5 +63,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('tablerow'.freeze, TableRow)
+  Template.register_tag('tablerow', TableRow)
 end

lib/liquid/tags/unless.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative 'if'
 
 module Liquid
@@ -24,5 +26,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('unless'.freeze, Unless)
+  Template.register_tag('unless', Unless)
 end

lib/liquid/template.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Templates are central to liquid.
   # Interpretating templates is a two step process. First you compile the
@@ -143,12 +145,7 @@ module Liquid
     end
 
     def instance_assigns
-      @instance_assigns ||= []
+      @instance_assigns ||= {}
-    end
-
-    def new_outer_scope
-      @instance_assigns.unshift(last = {})
-      last
     end
 
     def errors
@@ -170,7 +167,7 @@ module Liquid
     #    filters and tags and might be useful to integrate liquid more with its host application
     #
     def render(*args)
-      return ''.freeze if @root.nil?
+      return '' if @root.nil?
 
       context = case args.first
       when Liquid::Context
@@ -183,11 +180,11 @@ module Liquid
         c
       when Liquid::Drop
         drop = args.shift
-        drop.context = Context.new([drop, assigns].concat(instance_assigns), new_outer_scope, registers, @rethrow_errors, @resource_limits)
+        drop.context = Context.new([drop, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits)
       when Hash
-        Context.new([args.shift, assigns].concat(instance_assigns), new_outer_scope, registers, @rethrow_errors, @resource_limits)
+        Context.new([args.shift, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits)
       when nil
-        Context.new([assigns].concat(instance_assigns), new_outer_scope, registers, @rethrow_errors, @resource_limits)
+        Context.new(assigns, instance_assigns, registers, @rethrow_errors, @resource_limits)
       else
         raise ArgumentError, "Expected Hash or Liquid::Context as parameter"
       end
@@ -213,7 +210,7 @@ module Liquid
         # render the nodelist.
         # for performance reasons we get an array back here. join will make a string out of it.
         with_profiling(context) do
-          @root.render_to_output_buffer(context, output || '')
+          @root.render_to_output_buffer(context, output || +'')
         end
       rescue Liquid::MemoryError => e
         context.handle_error(e)

lib/liquid/tokenizer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Tokenizer
     attr_reader :line_number, :for_liquid_tag

lib/liquid/usage.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   module Usage
     def self.increment(name)

lib/liquid/utils.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   module Utils
     def self.slice_collection(collection, from, to)
@@ -50,7 +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
@@ -69,7 +71,7 @@ module Liquid
       end
 
       case obj
-      when 'now'.freeze, 'today'.freeze
+      when 'now', 'today'
         Time.now
       when /\A\d+\z/, Integer
         Time.at(obj.to_i)

lib/liquid/variable.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Holds variables. Variables are only loaded "just in time"
   # and are not evaluated as part of the render stage
@@ -108,7 +110,7 @@ module Liquid
       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

lib/liquid/variable_lookup.rb

@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 module Liquid
   class VariableLookup
     SQUARE_BRACKETED = /\A\[(.*)\]\z/m
-    COMMAND_METHODS = ['size'.freeze, 'first'.freeze, 'last'.freeze].freeze
+    COMMAND_METHODS = ['size', 'first', 'last'].freeze
 
     attr_reader :name, :lookups
 

lib/liquid/version.rb

@@ -1,5 +1,6 @@
 # encoding: utf-8
+# frozen_string_literal: true
 
 module Liquid
-  VERSION = "4.0.3".freeze
+  VERSION = "4.0.3"
 end

liquid.gemspec

@@ -1,4 +1,5 @@
 # encoding: utf-8
+# frozen_string_literal: true
 
 lib = File.expand_path('../lib/', __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)

performance/benchmark.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'benchmark/ips'
 require_relative 'theme_runner'
 

performance/profile.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'stackprof'
 require_relative 'theme_runner'
 
@@ -13,7 +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/comment_form.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CommentForm < Liquid::Block
   Syntax = /(#{Liquid::VariableSignature}+)/
 

performance/shopify/database.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'yaml'
 
 module Database
@@ -30,8 +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,
       }
 

performance/shopify/json_filter.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'json'
 
 module JsonFilter

performance/shopify/liquid.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 $LOAD_PATH.unshift(__dir__ + '/../../lib')
 require_relative '../../lib/liquid'
 

performance/shopify/money_filter.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MoneyFilter
   def money_with_currency(money)
     return '' if money.nil?

performance/shopify/paginate.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Paginate < Liquid::Block
   Syntax = /(#{Liquid::QuotedFragment})\s*(by\s*(\d+))?/
 

performance/shopify/shop_filter.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ShopFilter
   def asset_url(input)
     "/files/1/[shop_id]/[shop_id]/assets/#{input}"

performance/shopify/tag_filter.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module TagFilter
   def link_to_tag(label, tag)
     "<a title=\"Show tag #{tag}\" href=\"/collections/#{@context['handle']}/#{tag}\">#{label}</a>"

performance/shopify/weight_filter.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module WeightFilter
   def weight(grams)
     format("%.2f", grams / 1000)

performance/theme_runner.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This profiler run simulates Shopify.
 # We are looking in the tests directory for liquid files and render them within the designated layout file.
 # We will also export a substantial database to liquid which the templates can render values of.

test/integration/assign_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class AssignTest < Minitest::Test

test/integration/blank_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class FoobarTag < Liquid::Tag

test/integration/block_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class BlockTest < Minitest::Test

test/integration/capture_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class CaptureTest < Minitest::Test

test/integration/context_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ContextTest < Minitest::Test

test/integration/document_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class DocumentTest < Minitest::Test

test/integration/drop_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ContextDrop < Liquid::Drop
@@ -31,7 +33,7 @@ class ProductDrop < Liquid::Drop
 
   class CatchallDrop < Liquid::Drop
     def liquid_method_missing(method)
-      'catchall_method: ' << method.to_s
+      "catchall_method: #{method}"
     end
   end
 
@@ -48,7 +50,7 @@ class ProductDrop < Liquid::Drop
   end
 
   def user_input
-    "foo".taint
+    (+"foo").taint
   end
 
   protected
@@ -270,4 +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

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ErrorHandlingTest < Minitest::Test
@@ -209,7 +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)
@@ -223,7 +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/filter_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 module MoneyFilter

test/integration/hash_ordering_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class HashOrderingTest < Minitest::Test

test/integration/output_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 module FunnyFilter

test/integration/parsing_quirks_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ParsingQuirksTest < Minitest::Test

test/integration/render_profiling_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class RenderProfilingTest < Minitest::Test

test/integration/security_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 module SecurityFilter

test/integration/standard_filter_test.rb

@@ -1,4 +1,5 @@
 # encoding: utf-8
+# frozen_string_literal: true
 
 require 'test_helper'
 

test/integration/tags/break_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class BreakTagTest < Minitest::Test

test/integration/tags/continue_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ContinueTagTest < Minitest::Test

test/integration/tags/echo_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class EchoTest < Minitest::Test

test/integration/tags/for_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ThingWithValue < Liquid::Drop

test/integration/tags/if_else_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class IfElseTagTest < Minitest::Test

test/integration/tags/include_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class TestFileSystem

test/integration/tags/increment_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class IncrementTagTest < Minitest::Test

test/integration/tags/liquid_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class LiquidTagTest < Minitest::Test

test/integration/tags/raw_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class RawTagTest < Minitest::Test

test/integration/tags/render_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class RenderTagTest < Minitest::Test

test/integration/tags/standard_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class StandardTagTest < Minitest::Test