feat(attestation): add tiptap json to html converter

app/services/tiptap_service.rb

@@ -0,0 +1,65 @@
+class TiptapService
+  class << self
+    def to_html(node, tags)
+      children(node[:content], tags)
+    end
+
+    private
+
+    def children(content, tags)
+      content.map { node_to_html(_1, tags) }.join
+    end
+
+    def node_to_html(node, tags)
+      case node
+      in type: 'paragraph', content:, **rest
+        "<p#{text_align(rest[:attrs])}>#{children(content, tags)}</p>"
+      in type: 'heading', attrs: { level:, **attrs }, content:
+        "<h#{level}#{text_align(attrs)}>#{children(content, tags)}</h#{level}>"
+      in type: 'bulletList', content:
+        "<ul>#{children(content, tags)}</ul>"
+      in type: 'orderedList', content:
+        "<ol>#{children(content, tags)}</ol>"
+      in type: 'listItem', content:
+        "<li>#{children(content, tags)}</li>"
+      in type: 'text', text:, **rest
+        if rest[:marks].present?
+          apply_marks(text, rest[:marks])
+        else
+          text
+        end
+      in type: 'mention', attrs: { id: }, **rest
+        if rest[:marks].present?
+          apply_marks(tags[id], rest[:marks])
+        else
+          tags[id]
+        end
+      end
+    end
+
+    def text_align(attrs)
+      if attrs.present? && attrs[:textAlign].present?
+        " style=\"text-align: #{attrs[:textAlign]}\""
+      else
+        ""
+      end
+    end
+
+    def apply_marks(text, marks)
+      marks.reduce(text) do |text, mark|
+        case mark
+        in type: 'bold'
+          "<strong>#{text}</strong>"
+        in type: 'italic'
+          "<em>#{text}</em>"
+        in type: 'underline'
+          "<u>#{text}</u>"
+        in type: 'strike'
+          "<s>#{text}</s>"
+        in type: 'highlight'
+          "<mark>#{text}</mark>"
+        end
+      end
+    end
+  end
+end