From dd286425f5715b3c343f0e4df51508063bb56f64 Mon Sep 17 00:00:00 2001
From: Tatsuya Sato <satoryu.1981@gmail.com>
Date: Sun, 18 Oct 2026 01:03:56 +0900
Subject: [PATCH] Fix Element#prepend_to calling a missing Nokogiri method
 (#189)

prepend_to called element.node.properties, which does not exist on a
Nokogiri node, so it always raised NoMethodError. Use the container's
properties (w:pPr etc.) when present and insert after them; otherwise
insert the node as the first child.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 lib/docx/elements/element.rb       |  3 ++-
 spec/docx/elements/element_spec.rb | 30 ++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/lib/docx/elements/element.rb b/lib/docx/elements/element.rb
index fbe786c..039dda6 100755
--- a/lib/docx/elements/element.rb
+++ b/lib/docx/elements/element.rb
@@ -42,7 +42,8 @@ def append_to(element)
 
       # Insert node as first child (after properties)
       def prepend_to(element)
-        @node = element.node.properties.add_next_sibling(@node)
+        properties = element.properties if element.respond_to?(:properties)
+        @node = properties ? properties.add_next_sibling(@node) : element.node.prepend_child(@node)
         self
       end
 
diff --git a/spec/docx/elements/element_spec.rb b/spec/docx/elements/element_spec.rb
index a255415..ab852ef 100644
--- a/spec/docx/elements/element_spec.rb
+++ b/spec/docx/elements/element_spec.rb
@@ -98,6 +98,36 @@ def texts
     end
   end
 
+  # Regression tests for #189
+  describe '#prepend_to' do
+    let(:run) { element_class.new(w_node('<w:r><w:t>new </w:t></w:r>')) }
+
+    it 'inserts the node right after the properties of a container' do
+      paragraph = Docx::Elements::Containers::Paragraph.new(
+        w_node('<w:p><w:pPr><w:jc w:val="center"/></w:pPr><w:r><w:t>text</w:t></w:r></w:p>')
+      )
+
+      expect(run.prepend_to(paragraph)).to equal(run)
+      expect(paragraph.node.element_children.map(&:name)).to eq(%w[pPr r r])
+      expect(paragraph.text).to eq('new text')
+      expect(run.node.parent).to equal(paragraph.node)
+    end
+
+    it 'inserts the node as the first child of a container without properties' do
+      paragraph = Docx::Elements::Containers::Paragraph.new(w_node('<w:p><w:r><w:t>text</w:t></w:r></w:p>'))
+
+      run.prepend_to(paragraph)
+
+      expect(paragraph.text).to eq('new text')
+    end
+
+    it 'inserts the node as the first child of a non-container element' do
+      run.prepend_to(first)
+
+      expect(texts).to eq(%w[new\ first second])
+    end
+  end
+
   describe '.create_with' do
     it 'builds a detached element from the class tag in the same XML document' do
       created = element_class.create_with(first)