Remove hasnling false scopes

Remove lazy load stacks and instead only create a new scope when a tag is known to need one

.rubocop_todo.yml

@@ -1,6 +1,6 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2019-08-27 22:42:50 +1000 using RuboCop version 0.74.0.
+# on 2019-08-29 00:43:36 +1000 using RuboCop version 0.74.0.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
@@ -46,7 +46,7 @@ Layout/ClosingHeredocIndentation:
   Exclude:
     - 'test/integration/tags/for_tag_test.rb'
 
-# Offense count: 25
+# Offense count: 27
 # Cop supports --auto-correct.
 Layout/EmptyLineAfterGuardClause:
   Exclude:
@@ -104,7 +104,7 @@ Lint/Void:
   Exclude:
     - 'lib/liquid/parse_context.rb'
 
-# Offense count: 52
+# Offense count: 53
 Metrics/AbcSize:
   Max: 56
 
@@ -112,7 +112,7 @@ Metrics/AbcSize:
 Metrics/CyclomaticComplexity:
   Max: 13
 
-# Offense count: 114
+# Offense count: 118
 # Configuration parameters: CountComments, ExcludedMethods.
 Metrics/MethodLength:
   Max: 38
@@ -144,11 +144,12 @@ Naming/UncommunicativeMethodParamName:
     - 'test/integration/template_test.rb'
     - 'test/unit/condition_unit_test.rb'
 
-# Offense count: 3
+# Offense count: 5
 # Configuration parameters: EnforcedStyle.
 # SupportedStyles: inline, group
 Style/AccessModifierDeclarations:
   Exclude:
+    - 'lib/liquid/block_body.rb'
     - 'lib/liquid/tag.rb'
     - 'lib/liquid/tags/include.rb'
     - 'test/unit/strainer_unit_test.rb'
@@ -220,7 +221,7 @@ Style/FormatStringToken:
     - 'test/integration/filter_test.rb'
     - 'test/integration/hash_ordering_test.rb'
 
-# Offense count: 103
+# Offense count: 106
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle.
 # SupportedStyles: always, never
@@ -244,7 +245,7 @@ Style/GuardClause:
     - 'lib/liquid/variable.rb'
     - 'test/unit/tokenizer_unit_test.rb'
 
-# Offense count: 52
+# Offense count: 53
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle.
 # SupportedStyles: literals, strict
@@ -336,7 +337,7 @@ Style/WhileUntilModifier:
   Exclude:
     - 'lib/liquid/tags/case.rb'
 
-# Offense count: 650
+# Offense count: 665
 # Cop supports --auto-correct.
 # Configuration parameters: AutoCorrect, AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
 # URISchemes: http, https

lib/liquid/context.rb

@@ -25,8 +25,6 @@ module Liquid
       @resource_limits  = resource_limits || ResourceLimits.new(Template.default_resource_limits)
       squash_instance_assigns_with_environments
 
-      @this_stack_used = false
-
       self.exception_renderer = Template.default_exception_renderer
       if rethrow_errors
         self.exception_renderer = ->(e) { raise }
@@ -111,19 +109,11 @@ module Liquid
     #   end
     #
     #   context['var]  #=> nil
-    def stack(new_scope = nil)
-      old_stack_used = @this_stack_used
-      if new_scope
-        push(new_scope)
-        @this_stack_used = true
-      else
-        @this_stack_used = false
-      end
-
+    def stack(new_scope = {})
+      push(new_scope)
       yield
     ensure
-      pop if @this_stack_used
-      @this_stack_used = old_stack_used
+      pop
     end
 
     def clear_instance_assigns
@@ -132,10 +122,6 @@ module Liquid
 
     # Only allow String, Numeric, Hash, Array, Proc, Boolean or <tt>Liquid::Drop</tt>
     def []=(key, value)
-      unless @this_stack_used
-        @this_stack_used = true
-        push({})
-      end
       @scopes[0][key] = value
     end
 

lib/liquid/tags/case.rb

@@ -39,16 +39,14 @@ module Liquid
     end
 
     def render_to_output_buffer(context, output)
-      context.stack do
-        execute_else_block = true
+      execute_else_block = true
 
-        @blocks.each do |block|
-          if block.else?
-            block.attachment.render_to_output_buffer(context, output) if execute_else_block
-          elsif block.evaluate(context)
-            execute_else_block = false
-            block.attachment.render_to_output_buffer(context, output)
-          end
+      @blocks.each do |block|
+        if block.else?
+          block.attachment.render_to_output_buffer(context, output) if execute_else_block
+        elsif block.evaluate(context)
+          execute_else_block = false
+          block.attachment.render_to_output_buffer(context, output)
         end
       end
 

lib/liquid/tags/cycle.rb

@@ -34,25 +34,23 @@ module Liquid
     def render_to_output_buffer(context, output)
       context.registers[:cycle] ||= {}
 
-      context.stack do
-        key = context.evaluate(@name)
-        iteration = context.registers[:cycle][key].to_i
+      key = context.evaluate(@name)
+      iteration = context.registers[:cycle][key].to_i
 
-        val = context.evaluate(@variables[iteration])
+      val = context.evaluate(@variables[iteration])
 
-        if val.is_a?(Array)
-          val = val.join
-        elsif !val.is_a?(String)
-          val = val.to_s
-        end
-
-        output << val
-
-        iteration += 1
-        iteration  = 0 if iteration >= @variables.size
-        context.registers[:cycle][key] = iteration
+      if val.is_a?(Array)
+        val = val.join
+      elsif !val.is_a?(String)
+        val = val.to_s
       end
 
+      output << val
+
+      iteration += 1
+      iteration  = 0 if iteration >= @variables.size
+      context.registers[:cycle][key] = iteration
+
       output
     end
 

lib/liquid/tags/echo.rb

@@ -16,7 +16,7 @@ module Liquid
     end
 
     def render(context)
-      @variable.render(context)
+      @variable.render_to_output_buffer(context, '')
     end
   end
 

lib/liquid/tags/if.rb

@@ -40,11 +40,9 @@ module Liquid
     end
 
     def render_to_output_buffer(context, output)
-      context.stack do
-        @blocks.each do |block|
-          if block.evaluate(context)
-            return block.attachment.render_to_output_buffer(context, output)
-          end
+      @blocks.each do |block|
+        if block.evaluate(context)
+          return block.attachment.render_to_output_buffer(context, output)
         end
       end
 

lib/liquid/tags/ifchanged.rb

@@ -1,14 +1,12 @@
 module Liquid
   class Ifchanged < Block
     def render_to_output_buffer(context, output)
-      context.stack do
-        block_output = ''
-        super(context, block_output)
+      block_output = ''
+      super(context, block_output)
 
-        if block_output != context.registers[:ifchanged]
-          context.registers[:ifchanged] = block_output
-          output << block_output
-        end
+      if block_output != context.registers[:ifchanged]
+        context.registers[:ifchanged] = block_output
+        output << block_output
       end
 
       output

lib/liquid/tags/unless.rb

@@ -7,18 +7,16 @@ module Liquid
   #
   class Unless < If
     def render_to_output_buffer(context, output)
-      context.stack do
-        # First condition is interpreted backwards ( if not )
-        first_block = @blocks.first
-        unless first_block.evaluate(context)
-          return first_block.attachment.render_to_output_buffer(context, output)
-        end
+      # First condition is interpreted backwards ( if not )
+      first_block = @blocks.first
+      unless first_block.evaluate(context)
+        return first_block.attachment.render_to_output_buffer(context, output)
+      end
 
-        # After the first condition unless works just like if
-        @blocks[1..-1].each do |block|
-          if block.evaluate(context)
-            return block.attachment.render_to_output_buffer(context, output)
-          end
+      # After the first condition unless works just like if
+      @blocks[1..-1].each do |block|
+        if block.evaluate(context)
+          return block.attachment.render_to_output_buffer(context, output)
         end
       end
 

performance/memory_profile.rb

@@ -30,6 +30,7 @@ class Profiler
     @retained  << "#{report.scale_bytes(report.total_retained_memsize)} (#{report.total_retained} objects)"
 
     return if ENV['CI']
+
     require 'fileutils'
     report_file = File.join(REPORTS_DIR, "#{sanitize(phase)}.txt")
     FileUtils.mkdir_p(REPORTS_DIR)

test/integration/tags/liquid_tag_test.rb

@@ -5,72 +5,72 @@ class LiquidTagTest < Minitest::Test
 
   def test_liquid_tag
     assert_template_result('1 2 3', <<~LIQUID, 'array' => [1, 2, 3])
-    {%- liquid
-      echo array | join: " "
-    -%}
+      {%- liquid
+        echo array | join: " "
+      -%}
     LIQUID
 
     assert_template_result('1 2 3', <<~LIQUID, 'array' => [1, 2, 3])
-    {%- liquid
-      for value in array
-        echo value
-        unless forloop.last
-          echo " "
-        endunless
-      endfor
-    -%}
+      {%- liquid
+        for value in array
+          echo value
+          unless forloop.last
+            echo " "
+          endunless
+        endfor
+      -%}
     LIQUID
 
     assert_template_result('4 8 12 6', <<~LIQUID, 'array' => [1, 2, 3])
-    {%- liquid
-      for value in array
-        assign double_value = value | times: 2
-        echo double_value | times: 2
-        unless forloop.last
-          echo " "
-        endunless
-      endfor
+      {%- liquid
+        for value in array
+          assign double_value = value | times: 2
+          echo double_value | times: 2
+          unless forloop.last
+            echo " "
+          endunless
+        endfor
 
-      echo " "
-      echo double_value
-    -%}
+        echo " "
+        echo double_value
+      -%}
     LIQUID
 
     assert_template_result('abc', <<~LIQUID)
-    {%- liquid echo "a" -%}
-    b
-    {%- liquid echo "c" -%}
+      {%- liquid echo "a" -%}
+      b
+      {%- liquid echo "c" -%}
     LIQUID
   end
 
   def test_liquid_tag_errors
     assert_match_syntax_error("syntax error (line 1): Unknown tag 'error'", <<~LIQUID)
-    {%- liquid error no such tag -%}
+      {%- liquid error no such tag -%}
     LIQUID
 
     assert_match_syntax_error("syntax error (line 7): Unknown tag 'error'", <<~LIQUID)
-    {{ test }}
+      {{ test }}
 
-    {%-
-    liquid
-      for value in array
+      {%-
+      liquid
+        for value in array
 
-        error no such tag
-      endfor
-    -%}
+          error no such tag
+        endfor
+      -%}
     LIQUID
 
     assert_match_syntax_error("syntax error (line 2): Unknown tag '!!! the guards are vigilant'", <<~LIQUID)
-    {%- liquid
-      !!! the guards are vigilant
-    -%}
+      {%- liquid
+        !!! the guards are vigilant
+      -%}
     LIQUID
 
     assert_match_syntax_error("syntax error (line 4): 'for' tag was never closed", <<~LIQUID)
-    {%- liquid
-      for value in array
-        echo 'forgot to close the for tag'
-    -%}
+      {%- liquid
+        for value in array
+          echo 'forgot to close the for tag'
+      -%}
     LIQUID
   end
 
@@ -81,24 +81,24 @@ class LiquidTagTest < Minitest::Test
 
   def test_cannot_open_blocks_living_past_a_liquid_tag
     assert_match_syntax_error("syntax error (line 3): 'if' tag was never closed", <<~LIQUID)
-    {%- liquid
-      if true
-    -%}
-    {%- endif -%}
+      {%- liquid
+        if true
+      -%}
+      {%- endif -%}
     LIQUID
   end
 
   def test_quirk_can_close_blocks_created_before_a_liquid_tag
     assert_template_result("42", <<~LIQUID)
-    {%- if true -%}
-    42
-    {%- liquid endif -%}
+      {%- if true -%}
+      42
+      {%- liquid endif -%}
     LIQUID
   end
 
   def test_liquid_tag_in_raw
     assert_template_result("{% liquid echo 'test' %}\n", <<~LIQUID)
-    {% raw %}{% liquid echo 'test' %}{% endraw %}
+      {% raw %}{% liquid echo 'test' %}{% endraw %}
     LIQUID
   end
 end