Open youtube video link

Author: Umekawa

lib/qiita/markdown.rb

@@ -30,6 +30,7 @@
 require "qiita/markdown/filters/image_link"
 require "qiita/markdown/filters/inline_code_color"
 require "qiita/markdown/filters/mention"
+require "qiita/markdown/filters/open_content"
 require "qiita/markdown/filters/simplify"
 require "qiita/markdown/filters/syntax_highlight"
 require "qiita/markdown/filters/toc"

lib/qiita/markdown/filters/open_content.rb

@@ -0,0 +1,43 @@
+module Qiita
+  module Markdown
+    module Filters
+      class OpenContent < HTML::Pipeline::Filter
+        def call
+          doc.search("a.autolink").each do |node|
+            next if node["href"].blank?
+            next unless simple_anchor_tag?(node)
+
+            href = node["href"].strip
+            href_host = host_of(href)
+            next if href_host.blank?
+
+            if href.include?('https://www.youtube.com/watch?v=')
+              embed_href = href.gsub('www.youtube.com/watch?v=', 'www.youtube.com/embed/')
+              node.replace("<iframe width=\"560\" height=\"420\" src=\"#{embed_href}\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen></iframe>")
+            end
+          end
+          doc
+        end
+
+        private
+
+        def simple_anchor_tag?(node)
+          return false if node.children.any? { |child| child.name != 'text' }
+          return false if node.ancestors.any? do |ancestor|
+            next false if ancestor.name == '#document-fragment'
+            ancestor.name != 'p' || ancestor.children.size > 1
+          end
+
+          true
+        end
+
+        def host_of(url)
+          uri = ::Addressable::URI.parse(url)
+          uri.host
+        rescue ::Addressable::URI::InvalidURIError
+          nil
+        end
+      end
+    end
+  end
+end

lib/qiita/markdown/processor.rb

@@ -23,6 +23,7 @@ def self.default_filters
           Filters::GroupMention,
           Filters::ExternalLink,
           Filters::InlineCodeColor,
+          Filters::OpenContent,
           Filters::FinalSanitizer,
         ]
       end

spec/qiita/markdown/processor_spec.rb

@@ -1393,7 +1393,7 @@
       end
     end
 
-    shared_examples_for "override embed code attributes" do |allowed:|
+    shared_examples_for "override embed code attributes" do |allowed:, script:|
       context "with HTML embed code for CodePen using old script url" do
         let(:markdown) do
           <<-MARKDOWN.strip_heredoc
@@ -1511,6 +1511,31 @@
               end
             end
           end
+
+          context "when url is not embed code" do
+            let(:markdown) do
+              <<-MARKDOWN.strip_heredoc
+                #{url}
+              MARKDOWN
+            end
+
+            let(:url) {'https://www.youtube.com/watch?v=xxxxxx'}
+
+            if allowed || script
+              puts context
+              it "does not sanitize embed code" do
+                should eq <<-HTML.strip_heredoc
+                  <p><iframe width="560" height="420" src="https://www.youtube.com/embed/xxxxxx" frameborder="0" allowfullscreen></iframe></p>
+                HTML
+              end
+            else
+              it "forces width attribute on iframe" do
+                should eq <<-HTML.strip_heredoc
+                  <p><iframe width="100%" height="420" src="https://www.youtube.com/embed/xxxxxx" frameborder="0" allowfullscreen></iframe></p>
+                HTML
+              end
+            end
+          end
         end
 
         context "with scheme" do
@@ -1799,7 +1824,7 @@
       include_examples "data-attributes", allowed: false
       include_examples "class attribute", allowed: true
       include_examples "background-color", allowed: true
-      include_examples "override embed code attributes", allowed: false
+      include_examples "override embed code attributes", allowed: false, script: false
       include_examples "custom block", allowed: false
     end
 
@@ -1816,7 +1841,7 @@
       include_examples "data-attributes", allowed: true
       include_examples "class attribute", allowed: true
       include_examples "background-color", allowed: true
-      include_examples "override embed code attributes", allowed: true
+      include_examples "override embed code attributes", allowed: true, script: true
       include_examples "custom block", allowed: true
     end
 
@@ -1833,7 +1858,7 @@
       include_examples "data-attributes", allowed: false
       include_examples "class attribute", allowed: false
       include_examples "background-color", allowed: false
-      include_examples "override embed code attributes", allowed: false
+      include_examples "override embed code attributes", allowed: false, script: false
       include_examples "custom block", allowed: false
     end
 
@@ -1850,7 +1875,7 @@
       include_examples "data-attributes", allowed: false
       include_examples "class attribute", allowed: false
       include_examples "background-color", allowed: false
-      include_examples "override embed code attributes", allowed: false
+      include_examples "override embed code attributes", allowed: false, script: true
       include_examples "custom block", allowed: true
     end
   end