Expose tag body in the Doc tag

lib/liquid/tags/doc.rb

@@ -30,8 +30,11 @@ module Liquid
   class Doc < Block
     NO_UNEXPECTED_ARGS = /\A\s*\z/
 
+    attr_reader :body
+
     def initialize(tag_name, markup, parse_context)
       super
+      @body = +""
       ensure_valid_markup(tag_name, markup, parse_context)
     end
 
@@ -43,8 +46,10 @@ module Liquid
 
         if tag_name == block_delimiter
           parse_context.trim_whitespace = (token[-3] == WhitespaceControl)
+          @body << Regexp.last_match(1) if Regexp.last_match(1) != ""
           return
         end
+        @body << token unless token.empty?
       end
 
       raise_tag_never_closed(block_name)

test/unit/tags/doc_tag_unit_test.rb

@@ -20,6 +20,21 @@ class DocTagUnitTest < Minitest::Test
     assert_template_result('', template)
   end
 
+  def test_doc_tag_body_content
+    doc_content = "  Documentation content\n  @param {string} foo - test\n"
+    template_source = "{% doc %}#{doc_content}{% enddoc %}"
+
+    doc_tag = nil
+    ParseTreeVisitor
+      .for(Template.parse(template_source).root)
+      .add_callback_for(Liquid::Doc) do |tag|
+        doc_tag = tag
+      end
+      .visit
+
+    assert_equal(doc_content, doc_tag.body)
+  end
+
   def test_doc_tag_does_not_support_extra_arguments
     error = assert_raises(Liquid::SyntaxError) do
       template = <<~LIQUID.chomp