fix: Paragraphs in table cells skipped in import

Port HTML importer rules from enterprise fork

server/utils/turndown/sanitizeTables.ts

@@ -0,0 +1,43 @@
+import TurndownService from "turndown";
+
+/**
+ * A turndown plugin for removing incompatible nodes from tables.
+ *
+ * @param turndownService The TurndownService instance.
+ */
+export default function sanitizeTables(turndownService: TurndownService) {
+  function inHtmlContext(node: HTMLElement, selector: string) {
+    let currentNode = node;
+    // start at the closest element
+    while (currentNode !== null && currentNode.nodeType !== 1) {
+      currentNode = (currentNode.parentElement ||
+        currentNode.parentNode) as HTMLElement;
+    }
+    return (
+      currentNode !== null &&
+      currentNode.nodeType === 1 &&
+      currentNode.closest(selector) !== null
+    );
+  }
+
+  turndownService.addRule("headingsInTables", {
+    filter(node) {
+      return (
+        ["H1", "H2", "H3", "H4", "H5", "H6"].includes(node.nodeName) &&
+        inHtmlContext(node, "table")
+      );
+    },
+    replacement(content) {
+      return `**${content.trim()}**`;
+    },
+  });
+
+  turndownService.addRule("paragraphsInCells", {
+    filter(node) {
+      return node.nodeName === "P" && inHtmlContext(node, "table");
+    },
+    replacement(content) {
+      return content.trim();
+    },
+  });
+}