Add end tag support (#1823)

lib/liquid/block.rb

@@ -34,7 +34,7 @@ module Liquid
     end
 
     # @api private
-    def self.raise_unknown_tag(tag, block_name, block_delimiter, parse_context)
+    def self.raise_unknown_tag(tag, block_name, block_delimiter, parse_context, supports_end_tag = true)
       if tag == 'else'
         raise SyntaxError, parse_context.locale.t(
           "errors.syntax.unexpected_else",
@@ -42,7 +42,7 @@ module Liquid
         )
       elsif tag.start_with?('end')
         raise SyntaxError, parse_context.locale.t(
-          "errors.syntax.invalid_delimiter",
+          supports_end_tag ? "errors.syntax.invalid_delimiter" : "errors.syntax.invalid_delimiter_no_end",
           tag: tag,
           block_name: block_name,
           block_delimiter: block_delimiter,
@@ -64,6 +64,10 @@ module Liquid
       @block_delimiter ||= "end#{block_name}"
     end
 
+    def supports_end_tag?
+      true
+    end
+
     private
 
     # @api public
@@ -81,7 +85,7 @@ module Liquid
         body.parse(tokens, parse_context) do |end_tag_name, end_tag_params|
           @blank &&= body.blank?
 
-          return false if end_tag_name == block_delimiter
+          return false if end_tag_name == block_delimiter || (supports_end_tag? && end_tag_name == 'end')
           raise_tag_never_closed(block_name) unless end_tag_name
 
           # this tag is not registered with the system

lib/liquid/block_body.rb

@@ -68,7 +68,7 @@ module Liquid
 
     # @api private
     def self.unknown_tag_in_liquid_tag(tag, parse_context)
-      Block.raise_unknown_tag(tag, 'liquid', '%}', parse_context)
+      Block.raise_unknown_tag(tag, 'liquid', '%}', parse_context, false)
     end
 
     # @api private

lib/liquid/locales/en.yml

@@ -14,7 +14,8 @@
       if: "Syntax Error in tag 'if' - Valid syntax: if [expression]"
       include: "Error in tag 'include' - Valid syntax: include '[template]' (with|for) [object|collection]"
       inline_comment_invalid: "Syntax error in tag '#' - Each line of comments must be prefixed by the '#' character"
-      invalid_delimiter: "'%{tag}' is not a valid delimiter for %{block_name} tags. use %{block_delimiter}"
+      invalid_delimiter: "'%{tag}' is not a valid delimiter for %{block_name} tags. use end or %{block_delimiter}"
+      invalid_delimiter_no_end: "'%{tag}' is not a valid delimiter for %{block_name} tags. use %{block_delimiter}"
       render: "Syntax error in tag 'render' - Template name must be a quoted string"
       table_row: "Syntax Error in 'table_row loop' - Valid syntax: table_row [item] in [collection] cols=3"
       tag_never_closed: "'%{block_name}' tag was never closed"

lib/liquid/tags/comment.rb

@@ -22,6 +22,10 @@ module Liquid
     def unknown_tag(_tag, _markup, _tokens)
     end
 
+    def supports_end_tag?
+      false
+    end
+
     def blank?
       true
     end

lib/liquid/tags/raw.rb

@@ -22,6 +22,10 @@ module Liquid
       ensure_valid_markup(tag_name, markup, parse_context)
     end
 
+    def supports_end_tag?
+      false
+    end
+
     def parse(tokens)
       @body = +''
       while (token = tokens.shift)