Add 'data-turbo' => 'false' in markdown link to escape turbo-frames

app/helpers/application_helper.rb

@@ -7,7 +7,7 @@ def block_code(code, language)
   end
 
   MARKDOWN_RENDERER = Redcarpet::Markdown.new(
-    MarkdownRenderer.new(filter_html: true, hard_wrap: true),
+    MarkdownRenderer.new(filter_html: true, hard_wrap: true, link_attributes: { 'data-turbo' => 'false' }),
     fenced_code_blocks: true,
     no_intra_emphasis: true,
     autolink: true,

spec/helpers/application_helper_spec.rb

@@ -0,0 +1,18 @@
+require 'rails_helper'
+
+RSpec.describe ApplicationHelper, type: :helper do
+  describe '#markdown' do
+    it 'opts explicit links out of Turbo so they escape a surrounding turbo-frame' do
+      html = helper.markdown('see [example](https://example.com)')
+
+      expect(html).to include('href="https://example.com"')
+      expect(html).to include('data-turbo="false"')
+    end
+
+    it 'applies the same attribute to autolinked bare URLs' do
+      html = helper.markdown('visit https://example.com now')
+
+      expect(html).to include('data-turbo="false"')
+    end
+  end
+end