render_to_output_buffer

test/integration/blank_test.rb

@@ -1,12 +1,10 @@
 require 'test_helper'
 
 class FoobarTag < Liquid::Tag
-  def render(context, output = '')
+  def render_to_output_buffer(context, output)
     output << ' '
     output
   end
-
-  Liquid::Template.register_tag('foobar', FoobarTag)
 end
 
 class BlankTestFileSystem
@@ -32,7 +30,9 @@ class BlankTest < Minitest::Test
   end
 
   def test_new_tags_are_not_blank_by_default
-    assert_template_result(" " * N, wrap_in_for("{% foobar %}"))
+    with_custom_tag('foobar', FoobarTag) do
+      assert_template_result(" " * N, wrap_in_for("{% foobar %}"))
+    end
   end
 
   def test_loops_are_blank

test/integration/tags/include_tag_test.rb

@@ -66,7 +66,7 @@ class CustomInclude < Liquid::Tag
   def parse(tokens)
   end
 
-  def render(context, output = '')
+  def render_to_output_buffer(context, output)
     output << @template_name[1..-2]
     output
   end

test/integration/template_test.rb

@@ -177,31 +177,31 @@ class TemplateTest < Minitest::Test
 
   def test_render_length_persists_between_blocks
     t = Template.parse("{% if true %}aaaa{% endif %}")
-    t.resource_limits.render_length_limit = 3
+    t.resource_limits.render_length_limit = 7
     assert_equal "Liquid error: Memory limits exceeded", t.render
-    t.resource_limits.render_length_limit = 4
+    t.resource_limits.render_length_limit = 8
     assert_equal "aaaa", t.render
 
     t = Template.parse("{% if true %}aaaa{% endif %}{% if true %}bbb{% endif %}")
-    t.resource_limits.render_length_limit = 6
+    t.resource_limits.render_length_limit = 13
     assert_equal "Liquid error: Memory limits exceeded", t.render
-    t.resource_limits.render_length_limit = 7
+    t.resource_limits.render_length_limit = 14
     assert_equal "aaaabbb", t.render
 
     t = Template.parse("{% if true %}a{% endif %}{% if true %}b{% endif %}{% if true %}a{% endif %}{% if true %}b{% endif %}{% if true %}a{% endif %}{% if true %}b{% endif %}")
-    t.resource_limits.render_length_limit = 4
-    assert_equal "Liquid error: Memory limits exceeded", t.render
     t.resource_limits.render_length_limit = 5
     assert_equal "Liquid error: Memory limits exceeded", t.render
-    t.resource_limits.render_length_limit = 6
+    t.resource_limits.render_length_limit = 11
+    assert_equal "Liquid error: Memory limits exceeded", t.render
+    t.resource_limits.render_length_limit = 12
     assert_equal "ababab", t.render
   end
 
   def test_render_length_uses_number_of_bytes_not_characters
     t = Template.parse("{% if true %}すごい{% endif %}")
-    t.resource_limits.render_length_limit = 8
+    t.resource_limits.render_length_limit = 10
     assert_equal "Liquid error: Memory limits exceeded", t.render
-    t.resource_limits.render_length_limit = 9
+    t.resource_limits.render_length_limit = 18
     assert_equal "すごい", t.render
   end
 

test/test_helper.rb

@@ -84,6 +84,13 @@ module Minitest
     ensure
       Liquid::Template.error_mode = old_mode
     end
+
+    def with_custom_tag(tag_name, tag_class)
+      Liquid::Template.register_tag(tag_name, tag_class)
+      yield
+    ensure
+      Liquid::Template.tags.delete(tag_name)
+    end
   end
 end
 

test/unit/block_unit_test.rb

@@ -44,10 +44,47 @@ class BlockUnitTest < Minitest::Test
   end
 
   def test_with_custom_tag
-    Liquid::Template.register_tag("testtag", Block)
-    assert Liquid::Template.parse("{% testtag %} {% endtesttag %}")
-  ensure
-    Liquid::Template.tags.delete('testtag')
+    with_custom_tag('testtag', Block) do
+      assert Liquid::Template.parse("{% testtag %} {% endtesttag %}")
+    end
+  end
+
+  def test_custom_block_tags_have_a_default_render_to_output_buffer_method_for_backwards_compatibility
+    klass1 = Class.new(Block) do
+      def render(*)
+        'hello'
+      end
+    end
+
+    with_custom_tag('blabla', klass1) do
+      template = Liquid::Template.parse("{% blabla %} bla {% endblabla %}")
+
+      assert_equal 'hello', template.render
+
+      buf = ''
+      output = template.render({}, output: buf)
+      assert_equal 'hello', output
+      assert_equal 'hello', buf
+      assert_equal buf.object_id, output.object_id
+    end
+
+    klass2 = Class.new(klass1) do
+      def render(*)
+        'foo' + super + 'bar'
+      end
+    end
+
+    with_custom_tag('blabla', klass2) do
+      template = Liquid::Template.parse("{% blabla %} foo {% endblabla %}")
+
+      assert_equal 'foohellobar', template.render
+
+      buf = ''
+      output = template.render({}, output: buf)
+      assert_equal 'foohellobar', output
+      assert_equal 'foohellobar', buf
+      assert_equal buf.object_id, output.object_id
+    end
   end
 
   private

test/unit/tag_unit_test.rb

@@ -18,4 +18,42 @@ class TagUnitTest < Minitest::Test
     tag = Tag.parse("some_tag", "", Tokenizer.new(""), ParseContext.new)
     assert_equal 'some_tag', tag.tag_name
   end
+
+  def test_custom_tags_have_a_default_render_to_output_buffer_method_for_backwards_compatibility
+    klass1 = Class.new(Tag) do
+      def render(*)
+        'hello'
+      end
+    end
+
+    with_custom_tag('blabla', klass1) do
+      template = Liquid::Template.parse("{% blabla %}")
+
+      assert_equal 'hello', template.render
+
+      buf = ''
+      output = template.render({}, output: buf)
+      assert_equal 'hello', output
+      assert_equal 'hello', buf
+      assert_equal buf.object_id, output.object_id
+    end
+
+    klass2 = Class.new(klass1) do
+      def render(*)
+        'foo' + super + 'bar'
+      end
+    end
+
+    with_custom_tag('blabla', klass2) do
+      template = Liquid::Template.parse("{% blabla %}")
+
+      assert_equal 'foohellobar', template.render
+
+      buf = ''
+      output = template.render({}, output: buf)
+      assert_equal 'foohellobar', output
+      assert_equal 'foohellobar', buf
+      assert_equal buf.object_id, output.object_id
+    end
+  end
 end