Feat: Add support to Action Text enabled content (#365)

## What this does

Improved the `extract_content` method to correctly process Action Text.
When `message` model uses `has_rich_text :content`, `message.content`
becomes `ActionText:RichText`, returning HTML tags unintentionally.
Adjustments ensure only the desired content is extracted.

## Type of change

- [x] Bug fix
- [ ] New feature
- [ ] Breaking change
- [ ] Documentation
- [ ] Performance improvement

## Scope check

- [x] I read the [Contributing
Guide](https://github.com/crmne/ruby_llm/blob/main/CONTRIBUTING.md)
- [x] This aligns with RubyLLM's focus on **LLM communication**
- [x] This isn't application-specific logic that belongs in user code
- [x] This benefits most users, not just my specific use case

## Quality check

- [x] I ran `overcommit --install` and all hooks pass
- [x] I tested my changes thoroughly
- [x] I updated documentation if needed
- [x] I didn't modify auto-generated files manually (`models.json`,
`aliases.json`)

## API changes

- [ ] Breaking change
- [ ] New public methods/classes
- [ ] Changed method signatures
- [ ] No API changes

## Related issues

<!-- Link issues: "Fixes #123" or "Related to #123" -->

---------

Co-authored-by: Carmine Paolino <carmine@paolino.me>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 3 people

lib/ruby_llm/active_record/acts_as_legacy.rb

@@ -473,9 +473,15 @@ def extract_tool_call_id
       end
 
       def extract_content
-        return content unless respond_to?(:attachments) && attachments.attached?
+        text_content = if content.respond_to?(:to_plain_text)
+                         content.to_plain_text
+                       else
+                         content
+                       end
 
-        RubyLLM::Content.new(content).tap do |content_obj|
+        return text_content unless respond_to?(:attachments) && attachments.attached?
+
+        RubyLLM::Content.new(text_content).tap do |content_obj|
           @_tempfiles = []
 
           attachments.each do |attachment|

lib/ruby_llm/active_record/message_methods.rb

@@ -99,7 +99,8 @@ def extract_tool_call_id
       def extract_content
         return RubyLLM::Content::Raw.new(content_raw) if has_attribute?(:content_raw) && content_raw.present?
 
-        content_value = self[:content]
+        content_value = content
+        content_value = content_value.to_plain_text if content_value.respond_to?(:to_plain_text)
 
         return content_value unless respond_to?(:attachments) && attachments.attached?
 

spec/dummy/config/application.rb

@@ -7,6 +7,7 @@
 require 'active_record/railtie'
 require 'active_storage/engine'
 require 'action_controller/railtie'
+require 'action_text/engine'
 
 Bundler.require(*Rails.groups)
 

spec/ruby_llm/active_record/acts_as_action_text_spec.rb

@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe RubyLLM::ActiveRecord::ActsAs do
+  include_context 'with configured RubyLLM'
+
+  let(:chat) { Chat.create! }
+
+  def mock_action_text(plain_text)
+    instance_double(ActionText::RichText).tap do |mock|
+      allow(mock).to receive(:to_plain_text).and_return(plain_text)
+    end
+  end
+
+  def create_message_with_action_text(content_text)
+    message = chat.messages.create!(role: :user)
+    action_text_content = mock_action_text(content_text)
+    allow(message).to receive(:content).and_return(action_text_content)
+    [message, action_text_content]
+  end
+
+  describe 'Action Text content extraction' do
+    context 'when content responds to to_plain_text' do
+      it 'extracts plain text from Action Text content' do
+        message, action_text_content = create_message_with_action_text('This is plain text')
+
+        llm_message = message.to_llm
+
+        expect(action_text_content).to have_received(:to_plain_text)
+        expect(llm_message.content).to eq('This is plain text')
+      end
+    end
+
+    context 'when content is a regular string' do
+      it 'returns content unchanged' do
+        message = chat.messages.create!(role: :user, content: 'Regular text content')
+
+        expect(message.to_llm.content).to eq('Regular text content')
+      end
+    end
+
+    context 'when Action Text content has attachments' do
+      let(:test_attachment) do
+        { io: StringIO.new('test data'), filename: 'test.txt', content_type: 'text/plain' }
+      end
+
+      it 'combines Action Text with attachments into RubyLLM::Content' do
+        message, action_text_content = create_message_with_action_text('Rich text with attachment')
+        message.attachments.attach(test_attachment)
+
+        llm_message = message.to_llm
+
+        expect(action_text_content).to have_received(:to_plain_text)
+        expect(llm_message.content).to be_a(RubyLLM::Content)
+        expect(llm_message.content.text).to eq('Rich text with attachment')
+        expect(llm_message.content.attachments.first.mime_type).to eq('text/plain')
+      end
+    end
+  end
+end