diff --git a/app/models/post.rb b/app/models/post.rb
index 461733f..d5f7709 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -230,12 +230,14 @@ class Post
       template = public_send attr
 
       unless template.front_matter?
-        body += "\n\n"
+        body += "\n\n" if body.present?
         body += template.value
         next
       end
 
-      next if template.empty?
+      # Queremos mantener los Array en el resultado final para que
+      # siempre respondan a {% for %} en Liquid.
+      next if template.empty? && !template.value.is_a?(Array)
 
       [attr.to_s, template.value]
     end.compact.to_h
@@ -285,6 +287,7 @@ class Post
     return false unless write
 
     # Vuelve a leer el post para tomar los cambios
+    document.reset
     read
 
     written?
diff --git a/config/initializers/core_extensions.rb b/config/initializers/core_extensions.rb
index 8bbcbe7..d43a511 100644
--- a/config/initializers/core_extensions.rb
+++ b/config/initializers/core_extensions.rb
@@ -52,7 +52,7 @@ module Jekyll
 
     # Solo lee los datos
     def read_data
-      @site.data = DataReader.new(site).read(site.config["data_dir"])
+      @site.data = DataReader.new(site).read(site.config['data_dir'])
     end
 
     # Lee todos los artículos del sitio
@@ -73,6 +73,15 @@ module Jekyll
   Document.class_eval do
     alias_method :read!, :read
     def read; end
+
+    # Permitir restablecer el documento sin crear uno nuevo
+    def reset
+      @path = @extname = @has_yaml_header = @relative_path = nil
+      @basename_without_ext = @data = @basename = nil
+      @renderer = @url_placeholders = @url = nil
+      @to_liquid = @write_p = @excerpt_separator = @id = nil
+      @related_posts = @cleaned_relative_path = self.content = nil
+    end
   end
 
   # Prevenir la instanciación de Time
diff --git a/test/models/metadata_belongs_to_test.rb b/test/models/metadata_belongs_to_test.rb
index bf3f7b6..09b9714 100644
--- a/test/models/metadata_belongs_to_test.rb
+++ b/test/models/metadata_belongs_to_test.rb
@@ -12,6 +12,11 @@ class MetadataBelongsToTest < ActiveSupport::TestCase
 
     assert_equal post, reply.in_reply_to.belongs_to
     assert_includes post.posts.has_many, reply
+
+    assert post.save
+
+    assert_equal reply.document.data['in_reply_to'], post.document.data['uuid']
+    assert_includes post.document.data['posts'], reply.document.data['uuid']
   end
 
   test 'se puede eliminar la relación' do
@@ -19,12 +24,17 @@ class MetadataBelongsToTest < ActiveSupport::TestCase
     reply = @site.posts.create(layout: :post, title: SecureRandom.hex, in_reply_to: post.uuid.value)
 
     reply.in_reply_to.value = ''
-    reply.save
+    assert reply.save
 
     assert_not_equal post, reply.in_reply_to.belongs_to
     assert_equal post, reply.in_reply_to.belonged_to
     assert_nil reply.in_reply_to.belongs_to
     assert_not_includes post.posts.has_many, reply
+
+    assert post.save
+
+    assert_nil reply.document.data['in_reply_to']
+    assert_not_includes post.document.data['posts'], reply.document.data['uuid']
   end
 
   test 'se puede cambiar la relación' do
@@ -33,7 +43,7 @@ class MetadataBelongsToTest < ActiveSupport::TestCase
     reply = @site.posts.create(layout: :post, title: SecureRandom.hex, in_reply_to: post1.uuid.value)
 
     reply.in_reply_to.value = post2.uuid.value
-    reply.save
+    assert reply.save
 
     assert_not_equal post1, reply.in_reply_to.belongs_to
     assert_equal post1, reply.in_reply_to.belonged_to
@@ -41,5 +51,12 @@ class MetadataBelongsToTest < ActiveSupport::TestCase
 
     assert_equal post2, reply.in_reply_to.belongs_to
     assert_includes post2.posts.has_many, reply
+
+    assert post1.save
+    assert post2.save
+
+    assert_equal post2.document.data['uuid'], reply.document.data['in_reply_to']
+    assert_includes post2.document.data['posts'], reply.document.data['uuid']
+    assert_not_includes post1.document.data['posts'], reply.document.data['uuid']
   end
 end
diff --git a/test/models/metadata_has_and_belongs_to_many_test.rb b/test/models/metadata_has_and_belongs_to_many_test.rb
index 1404e14..4887a96 100644
--- a/test/models/metadata_has_and_belongs_to_many_test.rb
+++ b/test/models/metadata_has_and_belongs_to_many_test.rb
@@ -15,6 +15,11 @@ class MetadataHasAndBelongsManyTest < ActiveSupport::TestCase
 
     assert_includes author.posts.has_many, post
     assert_includes post.authors.has_many, author
+
+    assert author.save
+
+    assert_includes author.document.data['posts'], post.document.data['uuid']
+    assert_includes post.document.data['authors'], author.document.data['uuid']
   end
 
   test 'se puede eliminar la relación' do
@@ -25,7 +30,6 @@ class MetadataHasAndBelongsManyTest < ActiveSupport::TestCase
     assert_includes author.posts.value, post.uuid.value
 
     post.authors.value = []
-    ENV['HOLA'] = 'hola'
     assert post.save
 
     assert_not_includes author.posts.has_many, post
@@ -33,6 +37,11 @@ class MetadataHasAndBelongsManyTest < ActiveSupport::TestCase
 
     assert_includes author.posts.had_many, post
     assert_includes post.authors.had_many, author
+
+    assert author.save
+
+    assert_not_includes author.document.data['posts'], post.document.data['uuid']
+    assert_not_includes post.document.data['authors'], author.document.data['uuid']
   end
 
   test 'se puede cambiar la relación' do
@@ -54,5 +63,14 @@ class MetadataHasAndBelongsManyTest < ActiveSupport::TestCase
 
     assert_includes author.posts.has_many, post2
     assert_includes post2.authors.has_many, author
+
+    assert post1.save
+    assert post2.save
+
+    assert_not_includes author.document.data['posts'], post1.document.data['uuid']
+    assert_not_includes post1.document.data['authors'], author.document.data['uuid']
+
+    assert_includes author.document.data['posts'], post2.document.data['uuid']
+    assert_includes post2.document.data['authors'], author.document.data['uuid']
   end
 end
diff --git a/test/models/metadata_has_many_test.rb b/test/models/metadata_has_many_test.rb
index 637c942..38b4d46 100644
--- a/test/models/metadata_has_many_test.rb
+++ b/test/models/metadata_has_many_test.rb
@@ -12,6 +12,11 @@ class MetadataHasManyTest < ActiveSupport::TestCase
 
     assert_equal post, reply.in_reply_to.belongs_to
     assert_includes post.posts.has_many, reply
+
+    assert reply.save
+
+    assert_equal reply.document.data['in_reply_to'], post.document.data['uuid']
+    assert_includes post.document.data['posts'], reply.document.data['uuid']
   end
 
   test 'se puede eliminar la relación' do
@@ -19,12 +24,17 @@ class MetadataHasManyTest < ActiveSupport::TestCase
     post = @site.posts.create(layout: :post, title: SecureRandom.hex, posts: [reply.uuid.value])
 
     post.posts.value = []
-    post.save
+    assert post.save
 
     assert_not_equal post, reply.in_reply_to.belongs_to
     assert_equal post, reply.in_reply_to.belonged_to
     assert_nil reply.in_reply_to.belongs_to
     assert_not_includes post.posts.has_many, reply
+
+    assert reply.save
+
+    assert_nil reply.document.data['in_reply_to']
+    assert_not_includes post.document.data['posts'], reply.document.data['uuid']
   end
 
   test 'se puede cambiar la relación' do
@@ -33,7 +43,7 @@ class MetadataHasManyTest < ActiveSupport::TestCase
     post2 = @site.posts.create(layout: :post, title: SecureRandom.hex)
 
     reply.in_reply_to.value = post2.uuid.value
-    reply.save
+    assert reply.save
 
     assert_not_equal post1, reply.in_reply_to.belongs_to
     assert_equal post1, reply.in_reply_to.belonged_to
@@ -41,5 +51,12 @@ class MetadataHasManyTest < ActiveSupport::TestCase
 
     assert_equal post2, reply.in_reply_to.belongs_to
     assert_includes post2.posts.has_many, reply
+
+    assert post1.save
+    assert post2.save
+
+    assert_equal post2.document.data['uuid'], reply.document.data['in_reply_to']
+    assert_includes post2.document.data['posts'], reply.document.data['uuid']
+    assert_not_includes post1.document.data['posts'], reply.document.data['uuid']
   end
 end