Merge pull request #1143 from Shopify/styling-fixes-1

Apply simple rubocop fixes

lib/liquid/block.rb

@@ -28,15 +28,15 @@ module Liquid
 
     def unknown_tag(tag, _params, _tokens)
       if tag == 'else'.freeze
-        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unexpected_else".freeze,
-          block_name: block_name))
+        raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_else".freeze,
+          block_name: block_name)
       elsif tag.start_with?('end'.freeze)
-        raise SyntaxError.new(parse_context.locale.t("errors.syntax.invalid_delimiter".freeze,
+        raise SyntaxError, parse_context.locale.t("errors.syntax.invalid_delimiter".freeze,
           tag: tag,
           block_name: block_name,
-          block_delimiter: block_delimiter))
+          block_delimiter: block_delimiter)
       else
-        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unknown_tag".freeze, tag: tag))
+        raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag".freeze, tag: tag)
       end
     end
 
@@ -61,7 +61,7 @@ module Liquid
 
           return false if end_tag_name == block_delimiter
           unless end_tag_name
-            raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_never_closed".freeze, block_name: block_name))
+            raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed".freeze, block_name: block_name)
           end
 
           # this tag is not registered with the system

lib/liquid/block_body.rb

@@ -32,8 +32,8 @@ module Liquid
             # caller raise a syntax error
             return yield token, token
           end
-          tag_name = $1
-          markup = $2
+          tag_name = Regexp.last_match(1)
+          markup = Regexp.last_match(2)
           unless tag = registered_tags[tag_name]
             # end parsing if we reach an unknown tag and let the caller decide
             # determine how to proceed
@@ -58,13 +58,13 @@ module Liquid
           unless token =~ FullToken
             raise_missing_tag_terminator(token, parse_context)
           end
-          tag_name = $2
-          markup = $4
+          tag_name = Regexp.last_match(2)
+          markup = Regexp.last_match(4)
 
           if parse_context.line_number
             # newlines inside the tag should increase the line number,
             # particularly important for multiline {% liquid %} tags
-            parse_context.line_number += $1.count("\n".freeze) + $3.count("\n".freeze)
+            parse_context.line_number += Regexp.last_match(1).count("\n".freeze) + Regexp.last_match(3).count("\n".freeze)
           end
 
           if tag_name == 'liquid'.freeze
@@ -101,7 +101,7 @@ module Liquid
     def whitespace_handler(token, parse_context)
       if token[2] == WhitespaceControl
         previous_token = @nodelist.last
-        if previous_token.is_a? String
+        if previous_token.is_a?(String)
           previous_token.rstrip!
         end
       end
@@ -163,7 +163,7 @@ module Liquid
     def raise_if_resource_limits_reached(context, length)
       context.resource_limits.render_length += length
       return unless context.resource_limits.reached?
-      raise MemoryError.new("Memory limits exceeded".freeze)
+      raise MemoryError, "Memory limits exceeded".freeze
     end
 
     def create_variable(token, parse_context)
@@ -175,11 +175,11 @@ module Liquid
     end
 
     def raise_missing_tag_terminator(token, parse_context)
-      raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_termination".freeze, token: token, tag_end: TagEnd.inspect))
+      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_termination".freeze, token: token, tag_end: TagEnd.inspect)
     end
 
     def raise_missing_variable_terminator(token, parse_context)
-      raise SyntaxError.new(parse_context.locale.t("errors.syntax.variable_termination".freeze, token: token, tag_end: VariableEnd.inspect))
+      raise SyntaxError, parse_context.locale.t("errors.syntax.variable_termination".freeze, token: token, tag_end: VariableEnd.inspect)
     end
 
     def registered_tags

lib/liquid/condition.rb

@@ -11,18 +11,18 @@ module Liquid
       '=='.freeze => ->(cond, left, right) {  cond.send(:equal_variables, left, right) },
       '!='.freeze => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
       '<>'.freeze => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
-      '<'.freeze  => :<,
-      '>'.freeze  => :>,
+      '<'.freeze => :<,
+      '>'.freeze => :>,
       '>='.freeze => :>=,
       '<='.freeze => :<=,
-      'contains'.freeze => lambda do |cond, left, right|
+      'contains'.freeze => lambda do |_cond, left, right|
         if left && right && left.respond_to?(:include?)
           right = right.to_s if left.is_a?(String)
           left.include?(right)
         else
           false
         end
-      end
+      end,
     }
 
     def self.operators
@@ -36,7 +36,7 @@ module Liquid
       @left = left
       @operator = operator
       @right = right
-      @child_relation  = nil
+      @child_relation = nil
       @child_condition = nil
     end
 
@@ -116,7 +116,7 @@ module Liquid
       left = context.evaluate(left)
       right = context.evaluate(right)
 
-      operation = self.class.operators[op] || raise(Liquid::ArgumentError.new("Unknown operator #{op}"))
+      operation = self.class.operators[op] || raise(Liquid::ArgumentError, "Unknown operator #{op}")
 
       if operation.respond_to?(:call)
         operation.call(self, left, right)
@@ -124,7 +124,7 @@ module Liquid
         begin
           left.send(operation, right)
         rescue ::ArgumentError => e
-          raise Liquid::ArgumentError.new(e.message)
+          raise Liquid::ArgumentError, e.message
         end
       end
     end

lib/liquid/context.rb

@@ -37,7 +37,7 @@ module Liquid
 
       self.exception_renderer = Template.default_exception_renderer
       if rethrow_errors
-        self.exception_renderer = ->(e) { raise }
+        self.exception_renderer = ->(_e) { raise }
       end
 
       @interrupts = []
@@ -201,7 +201,7 @@ module Liquid
       value = obj[key]
 
       if value.is_a?(Proc) && obj.respond_to?(:[]=)
-        obj[key] = (value.arity == 0) ? value.call : value.call(self)
+        obj[key] = value.arity == 0 ? value.call : value.call(self)
       else
         value
       end

lib/liquid/document.rb

@@ -7,7 +7,7 @@ module Liquid
     end
 
     def parse(tokens, parse_context)
-      super do |end_tag_name, end_tag_params|
+      super do |end_tag_name, _end_tag_params|
         unknown_tag(end_tag_name, parse_context) if end_tag_name
       end
     rescue SyntaxError => e
@@ -18,9 +18,9 @@ module Liquid
     def unknown_tag(tag, parse_context)
       case tag
       when 'else'.freeze, 'end'.freeze
-        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unexpected_outer_tag".freeze, tag: tag))
+        raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_outer_tag".freeze, tag: tag)
       else
-        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unknown_tag".freeze, tag: tag))
+        raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag".freeze, tag: tag)
       end
     end
   end

lib/liquid/drop.rb

@@ -25,7 +25,7 @@ module Liquid
 
     # Catch all for the method
     def liquid_method_missing(method)
-      return nil unless @context && @context.strict_variables
+      return nil unless @context&.strict_variables
       raise Liquid::UndefinedDropMethod, "undefined method #{method}"
     end
 

lib/liquid/errors.rb

@@ -21,10 +21,10 @@ module Liquid
 
     def message_prefix
       str = ""
-      if is_a?(SyntaxError)
-        str << "Liquid syntax error"
+      str << if is_a?(SyntaxError)
+        "Liquid syntax error"
       else
-        str << "Liquid error"
+        "Liquid error"
       end
 
       if line_number

lib/liquid/expression.rb

@@ -15,7 +15,7 @@ module Liquid
 
     LITERALS = {
       nil => nil, 'nil'.freeze => nil, 'null'.freeze => nil, ''.freeze => nil,
-      'true'.freeze  => true,
+      'true'.freeze => true,
       'false'.freeze => false,
       'blank'.freeze => MethodLiteral.new(:blank?, '').freeze,
       'empty'.freeze => MethodLiteral.new(:empty?, '').freeze
@@ -33,13 +33,13 @@ module Liquid
       else
         case markup
         when SINGLE_QUOTED_STRING, DOUBLE_QUOTED_STRING
-          $1
+          Regexp.last_match(1)
         when INTEGERS_REGEX
-          $1.to_i
+          Regexp.last_match(1).to_i
         when RANGES_REGEX
-          RangeLookup.parse($1, $2)
+          RangeLookup.parse(Regexp.last_match(1), Regexp.last_match(2))
         when FLOATS_REGEX
-          $1.to_f
+          Regexp.last_match(1).to_f
         else
           VariableLookup.parse(markup)
         end

lib/liquid/file_system.rb

@@ -57,7 +57,7 @@ module Liquid
     end
 
     def full_path(template_path)
-      raise FileSystemError, "Illegal template name '#{template_path}'" unless template_path =~ /\A[^.\/][a-zA-Z0-9_\/]+\z/
+      raise FileSystemError, "Illegal template name '#{template_path}'" unless template_path =~ %r{\A[^./][a-zA-Z0-9_/]+\z}
 
       full_path = if template_path.include?('/'.freeze)
         File.join(root, File.dirname(template_path), @pattern % File.basename(template_path))

lib/liquid/i18n.rb

@@ -26,13 +26,13 @@ module Liquid
     def interpolate(name, vars)
       name.gsub(/%\{(\w+)\}/) do
         # raise TranslationError, "Undefined key #{$1} for interpolation in translation #{name}"  unless vars[$1.to_sym]
-        (vars[$1.to_sym]).to_s
+        (vars[Regexp.last_match(1).to_sym]).to_s
       end
     end
 
     def deep_fetch_translation(name)
       name.split('.'.freeze).reduce(locale) do |level, cur|
-        level[cur] or raise TranslationError, "Translation for #{name} does not exist in locale #{path}"
+        level[cur] || raise(TranslationError, "Translation for #{name} does not exist in locale #{path}")
       end
     end
   end

lib/liquid/lexer.rb

@@ -11,7 +11,7 @@ module Liquid
       '('.freeze => :open_round,
       ')'.freeze => :close_round,
       '?'.freeze => :question,
-      '-'.freeze => :dash
+      '-'.freeze => :dash,
     }.freeze
     IDENTIFIER = /[a-zA-Z_][\w-]*\??/
     SINGLE_STRING_LITERAL = /'[^\']*'/
@@ -31,13 +31,12 @@ module Liquid
       until @ss.eos?
         @ss.skip(WHITESPACE_OR_NOTHING)
         break if @ss.eos?
-        tok = case
-        when t = @ss.scan(COMPARISON_OPERATOR) then [:comparison, t]
-        when t = @ss.scan(SINGLE_STRING_LITERAL) then [:string, t]
-        when t = @ss.scan(DOUBLE_STRING_LITERAL) then [:string, t]
-        when t = @ss.scan(NUMBER_LITERAL) then [:number, t]
-        when t = @ss.scan(IDENTIFIER) then [:id, t]
-        when t = @ss.scan(DOTDOT) then [:dotdot, t]
+        tok = if t = @ss.scan(COMPARISON_OPERATOR) then [:comparison, t]
+        elsif t = @ss.scan(SINGLE_STRING_LITERAL) then [:string, t]
+        elsif t = @ss.scan(DOUBLE_STRING_LITERAL) then [:string, t]
+        elsif t = @ss.scan(NUMBER_LITERAL) then [:number, t]
+        elsif t = @ss.scan(IDENTIFIER) then [:id, t]
+        elsif t = @ss.scan(DOTDOT) then [:dotdot, t]
         else
           c = @ss.getch
           if s = SPECIALS[c]

lib/liquid/parse_context.rb

@@ -28,7 +28,7 @@ module Liquid
         if dont_pass == true
           { locale: locale }
         elsif dont_pass.is_a?(Array)
-          @template_options.reject { |k, v| dont_pass.include?(k) }
+          @template_options.reject { |k, _v| dont_pass.include?(k) }
         else
           @template_options
         end

lib/liquid/parse_tree_visitor.rb

@@ -28,7 +28,7 @@ module Liquid
         item, new_context = @callbacks[node.class].call(node, context)
         [
           item,
-          ParseTreeVisitor.for(node, @callbacks).visit(new_context || context)
+          ParseTreeVisitor.for(node, @callbacks).visit(new_context || context),
         ]
       end
     end

lib/liquid/parser.rb

@@ -51,7 +51,7 @@ module Liquid
       token = @tokens[@p]
       if token[0] == :id
         variable_signature
-      elsif SINGLE_TOKEN_EXPRESSION_TYPES.include? token[0]
+      elsif SINGLE_TOKEN_EXPRESSION_TYPES.include?(token[0])
         consume
       elsif token.first == :open_round
         consume

lib/liquid/standardfilters.rb

@@ -8,13 +8,13 @@ module Liquid
       '>'.freeze => '>'.freeze,
       '<'.freeze => '&lt;'.freeze,
       '"'.freeze => '&quot;'.freeze,
-      "'".freeze => '&#39;'.freeze
+      "'".freeze => '&#39;'.freeze,
     }.freeze
     HTML_ESCAPE_ONCE_REGEXP = /["><']|&(?!([a-zA-Z]+|(#\d+));)/
     STRIP_HTML_BLOCKS = Regexp.union(
-      /<script.*?<\/script>/m,
+      %r{<script.*?</script>}m,
       /<!--.*?-->/m,
-      /<style.*?<\/style>/m
+      %r{<style.*?</style>}m
     )
     STRIP_HTML_TAGS = /<.*?>/m
 
@@ -276,7 +276,7 @@ module Liquid
 
     def concat(input, array)
       unless array.respond_to?(:to_ary)
-        raise ArgumentError.new("concat filter requires an array argument")
+        raise ArgumentError, "concat filter requires an array argument"
       end
       InputIterator.new(input).concat(array)
     end
@@ -430,7 +430,7 @@ module Liquid
     private
 
     def raise_property_error(property)
-      raise Liquid::ArgumentError.new("cannot select the property '#{property}'")
+      raise Liquid::ArgumentError, "cannot select the property '#{property}'"
     end
 
     def apply_operation(input, operand, operation)

lib/liquid/strainer.rb

@@ -27,7 +27,7 @@ module Liquid
 
     def self.add_filter(filter)
       raise ArgumentError, "Expected module but got: #{filter.class}" unless filter.is_a?(Module)
-      unless self.include?(filter)
+      unless include?(filter)
         invokable_non_public_methods = (filter.private_instance_methods + filter.protected_instance_methods).select { |m| invokable?(m) }
         if invokable_non_public_methods.any?
           raise MethodOverrideError, "Filter overrides registered public methods as non public: #{invokable_non_public_methods.join(', ')}"
@@ -54,7 +54,7 @@ module Liquid
     def invoke(method, *args)
       if self.class.invokable?(method)
         send(method, *args)
-      elsif @context && @context.strict_filters
+      elsif @context&.strict_filters
         raise Liquid::UndefinedFilter, "undefined filter #{method}"
       else
         args.first

lib/liquid/tags/assign.rb

@@ -19,10 +19,10 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
       if markup =~ Syntax
-        @to = $1
-        @from = Variable.new($2, options)
+        @to = Regexp.last_match(1)
+        @from = Variable.new(Regexp.last_match(2), options)
       else
-        raise SyntaxError.new(options[:locale].t(self.class.syntax_error_translation_key))
+        raise SyntaxError, options[:locale].t(self.class.syntax_error_translation_key)
       end
     end
 

lib/liquid/tags/capture.rb

@@ -16,9 +16,9 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
       if markup =~ Syntax
-        @to = $1
+        @to = Regexp.last_match(1)
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.capture"))
+        raise SyntaxError, options[:locale].t("errors.syntax.capture")
       end
     end
 

lib/liquid/tags/case.rb

@@ -10,17 +10,15 @@ module Liquid
       @blocks = []
 
       if markup =~ Syntax
-        @left = Expression.parse($1)
+        @left = Expression.parse(Regexp.last_match(1))
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.case".freeze))
+        raise SyntaxError, options[:locale].t("errors.syntax.case".freeze)
       end
     end
 
     def parse(tokens)
       body = BlockBody.new
-      while parse_body(body, tokens)
-        body = @blocks.last.attachment
-      end
+      body = @blocks.last.attachment while parse_body(body, tokens)
     end
 
     def nodelist
@@ -60,12 +58,12 @@ module Liquid
 
       while markup
         unless markup =~ WhenSyntax
-          raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_when".freeze))
+          raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_when".freeze)
         end
 
-        markup = $2
+        markup = Regexp.last_match(2)
 
-        block = Condition.new(@left, '=='.freeze, Expression.parse($1))
+        block = Condition.new(@left, '=='.freeze, Expression.parse(Regexp.last_match(1)))
         block.attach(body)
         @blocks << block
       end
@@ -73,7 +71,7 @@ module Liquid
 
     def record_else_condition(markup)
       unless markup.strip.empty?
-        raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_else".freeze))
+        raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_else".freeze)
       end
 
       block = ElseCondition.new

lib/liquid/tags/cycle.rb

@@ -21,13 +21,13 @@ module Liquid
       super
       case markup
       when NamedSyntax
-        @variables = variables_from_string($2)
-        @name = Expression.parse($1)
+        @variables = variables_from_string(Regexp.last_match(2))
+        @name = Expression.parse(Regexp.last_match(1))
       when SimpleSyntax
         @variables = variables_from_string(markup)
         @name = @variables.to_s
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.cycle".freeze))
+        raise SyntaxError, options[:locale].t("errors.syntax.cycle".freeze)
       end
     end
 
@@ -59,7 +59,7 @@ module Liquid
     def variables_from_string(markup)
       markup.split(',').collect do |var|
         var =~ /\s*(#{QuotedFragment})\s*/o
-        $1 ? Expression.parse($1) : nil
+        Regexp.last_match(1) ? Expression.parse(Regexp.last_match(1)) : nil
       end.compact
     end
 

lib/liquid/tags/for.rb

@@ -86,23 +86,23 @@ module Liquid
 
     def lax_parse(markup)
       if markup =~ Syntax
-        @variable_name = $1
-        collection_name = $2
-        @reversed = !!$3
+        @variable_name = Regexp.last_match(1)
+        collection_name = Regexp.last_match(2)
+        @reversed = !!Regexp.last_match(3)
         @name = "#{@variable_name}-#{collection_name}"
         @collection_name = Expression.parse(collection_name)
         markup.scan(TagAttributes) do |key, value|
           set_attribute(key, value)
         end
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.for".freeze))
+        raise SyntaxError, options[:locale].t("errors.syntax.for".freeze)
       end
     end
 
     def strict_parse(markup)
       p = Parser.new(markup)
       @variable_name = p.consume(:id)
-      raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_in".freeze)) unless p.id?('in'.freeze)
+      raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_in".freeze) unless p.id?('in'.freeze)
       collection_name = p.expression
       @name = "#{@variable_name}-#{collection_name}"
       @collection_name = Expression.parse(collection_name)
@@ -110,7 +110,7 @@ module Liquid
 
       while p.look(:id) && p.look(:colon, 1)
         unless attribute = p.id?('limit'.freeze) || p.id?('offset'.freeze)
-          raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_attribute".freeze))
+          raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_attribute".freeze)
         end
         p.consume
         set_attribute(attribute, p.expression)
@@ -170,11 +170,10 @@ module Liquid
             loop_vars.send(:increment!)
 
             # Handle any interrupts if they exist.
-            if context.interrupt?
-              interrupt = context.pop_interrupt
-              break if interrupt.is_a? BreakInterrupt
-              next if interrupt.is_a? ContinueInterrupt
-            end
+            next unless context.interrupt?
+            interrupt = context.pop_interrupt
+            break if interrupt.is_a?(BreakInterrupt)
+            next if interrupt.is_a?(ContinueInterrupt)
           end
         ensure
           for_stack.pop

lib/liquid/tags/if.rb

@@ -64,17 +64,17 @@ module Liquid
 
     def lax_parse(markup)
       expressions = markup.scan(ExpressionsAndOperators)
-      raise(SyntaxError.new(options[:locale].t("errors.syntax.if".freeze))) unless expressions.pop =~ Syntax
+      raise SyntaxError, options[:locale].t("errors.syntax.if".freeze) unless expressions.pop =~ Syntax
 
-      condition = Condition.new(Expression.parse($1), $2, Expression.parse($3))
+      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.new(options[:locale].t("errors.syntax.if".freeze))) unless expressions.pop.to_s =~ Syntax
+        raise SyntaxError, options[:locale].t("errors.syntax.if".freeze) unless expressions.pop.to_s =~ Syntax
 
-        new_condition = Condition.new(Expression.parse($1), $2, Expression.parse($3))
-        raise(SyntaxError.new(options[:locale].t("errors.syntax.if".freeze))) unless BOOLEAN_OPERATORS.include?(operator)
+        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)
         new_condition.send(operator, condition)
         condition = new_condition
       end

lib/liquid/tags/include.rb

@@ -23,8 +23,8 @@ module Liquid
 
       if markup =~ Syntax
 
-        template_name = $1
-        variable_name = $3
+        template_name = Regexp.last_match(1)
+        variable_name = Regexp.last_match(3)
 
         @variable_name_expr = variable_name ? Expression.parse(variable_name) : nil
         @template_name_expr = Expression.parse(template_name)
@@ -35,7 +35,7 @@ module Liquid
         end
 
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.include".freeze))
+        raise SyntaxError, options[:locale].t("errors.syntax.include".freeze)
       end
     end
 
@@ -44,7 +44,7 @@ module Liquid
 
     def render_to_output_buffer(context, output)
       template_name = context.evaluate(@template_name_expr)
-      raise ArgumentError.new(options[:locale].t("errors.argument.include")) unless template_name
+      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name
 
       partial = PartialCache.load(
         template_name,
@@ -95,7 +95,7 @@ module Liquid
       def children
         [
           @node.template_name_expr,
-          @node.variable_name_expr
+          @node.variable_name_expr,
         ] + @node.attributes.values
       end
     end

lib/liquid/tags/raw.rb

@@ -13,13 +13,13 @@ module Liquid
       @body = ''
       while token = tokens.shift
         if token =~ FullTokenPossiblyInvalid
-          @body << $1 if $1 != "".freeze
-          return if block_delimiter == $2
+          @body << Regexp.last_match(1) if Regexp.last_match(1) != "".freeze
+          return if block_delimiter == Regexp.last_match(2)
         end
         @body << token unless token.empty?
       end
 
-      raise SyntaxError.new(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".freeze, block_name: block_name)
     end
 
     def render_to_output_buffer(_context, output)
@@ -39,7 +39,7 @@ module Liquid
 
     def ensure_valid_markup(tag_name, markup, parse_context)
       unless markup =~ Syntax
-        raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_unexpected_args".freeze, tag: tag_name))
+        raise SyntaxError, parse_context.locale.t("errors.syntax.tag_unexpected_args".freeze, tag: tag_name)
       end
     end
   end

lib/liquid/tags/render.rb

@@ -7,9 +7,9 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
 
-      raise SyntaxError.new(options[:locale].t("errors.syntax.render".freeze)) unless markup =~ SYNTAX
+      raise SyntaxError, options[:locale].t("errors.syntax.render".freeze) unless markup =~ SYNTAX
 
-      template_name = $1
+      template_name = Regexp.last_match(1)
 
       @template_name_expr = Expression.parse(template_name)
 
@@ -22,7 +22,7 @@ module Liquid
     def render_to_output_buffer(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.new(options[:locale].t("errors.argument.include")) unless template_name
+      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name
 
       partial = PartialCache.load(
         template_name,

lib/liquid/tags/table_row.rb

@@ -7,19 +7,19 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
       if markup =~ Syntax
-        @variable_name = $1
-        @collection_name = Expression.parse($2)
+        @variable_name = Regexp.last_match(1)
+        @collection_name = Expression.parse(Regexp.last_match(2))
         @attributes = {}
         markup.scan(TagAttributes) do |key, value|
           @attributes[key] = Expression.parse(value)
         end
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.table_row".freeze))
+        raise SyntaxError, options[:locale].t("errors.syntax.table_row".freeze)
       end
     end
 
     def render_to_output_buffer(context, output)
-      collection = context.evaluate(@collection_name) or return ''.freeze
+      (collection = context.evaluate(@collection_name)) || (return ''.freeze)
 
       from = @attributes.key?('offset'.freeze) ? context.evaluate(@attributes['offset'.freeze]).to_i : 0
       to = @attributes.key?('limit'.freeze) ? from + context.evaluate(@attributes['limit'.freeze]).to_i : nil

lib/liquid/template.rb

@@ -172,7 +172,7 @@ module Liquid
         c = args.shift
 
         if @rethrow_errors
-          c.exception_renderer = ->(e) { raise }
+          c.exception_renderer = ->(_e) { raise }
         end
 
         c

lib/liquid/tokenizer.rb

@@ -10,7 +10,7 @@ module Liquid
     end
 
     def shift
-      token = @tokens.shift or return
+      (token = @tokens.shift) || return
 
       if @line_number
         @line_number += @for_liquid_tag ? 1 : token.count("\n")
@@ -29,7 +29,7 @@ module Liquid
       tokens = @source.split(TemplateParser)
 
       # removes the rogue empty element at the beginning of the array
-      tokens.shift if tokens[0] && tokens[0].empty?
+      tokens.shift if tokens[0]&.empty?
 
       tokens
     end

lib/liquid/utils.rb

@@ -50,7 +50,7 @@ module Liquid
       when Numeric
         obj
       when String
-        (obj.strip =~ /\A-?\d+\.\d+\z/) ? BigDecimal(obj) : obj.to_i
+        obj.strip =~ /\A-?\d+\.\d+\z/ ? BigDecimal(obj) : obj.to_i
       else
         if obj.respond_to?(:to_number)
           obj.to_number

lib/liquid/variable.rb

@@ -43,11 +43,11 @@ module Liquid
       @filters = []
       return unless markup =~ MarkupWithQuotedFragment
 
-      name_markup = $1
-      filter_markup = $2
+      name_markup = Regexp.last_match(1)
+      filter_markup = Regexp.last_match(2)
       @name = Expression.parse(name_markup)
       if filter_markup =~ FilterMarkupRegex
-        filters = $1.scan(FilterParser)
+        filters = Regexp.last_match(1).scan(FilterParser)
         filters.each do |f|
           next unless f =~ /\w+/
           filtername = Regexp.last_match(0)
@@ -121,7 +121,7 @@ module Liquid
     end
 
     def evaluate_filter_expressions(context, filter_args, filter_kwargs)
-      parsed_args = filter_args.map{ |expr| context.evaluate(expr) }
+      parsed_args = filter_args.map { |expr| context.evaluate(expr) }
       if filter_kwargs
         parsed_kwargs = {}
         filter_kwargs.each do |key, expr|

lib/liquid/variable_lookup.rb

@@ -14,7 +14,7 @@ module Liquid
 
       name = lookups.shift
       if name =~ SQUARE_BRACKETED
-        name = Expression.parse($1)
+        name = Expression.parse(Regexp.last_match(1))
       end
       @name = name
 
@@ -24,7 +24,7 @@ module Liquid
       @lookups.each_index do |i|
         lookup = lookups[i]
         if lookup =~ SQUARE_BRACKETED
-          lookups[i] = Expression.parse($1)
+          lookups[i] = Expression.parse(Regexp.last_match(1))
         elsif COMMAND_METHODS.include?(lookup)
           @command_flags |= 1 << i
         end