From c982b3e90f709545405b12e986075fdc33396a49 Mon Sep 17 00:00:00 2001
From: Amit Haridas <amit.wh@gmail.com>
Date: Mon, 25 May 2026 00:32:27 +0530
Subject: [PATCH] chore(diagnostics): add logging to _renderPreview to trace
 markdown rendering

This will help identify whether the issue is:
1. marked.parse returning a Promise instead of string
2. DOMPurify.sanitize failing
3. The preview element not existing
4. Libraries not being loaded

Amit Haridas
---
 src/renderer.js | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/renderer.js b/src/renderer.js
index 3e3b989..4515353 100644
--- a/src/renderer.js
+++ b/src/renderer.js
@@ -682,17 +682,26 @@ class TabManager {
     _renderPreview(tabId) {
         const tab = this.tabs.get(tabId);
         const preview = document.getElementById(`preview-${tabId}`);
+        console.log('[_renderPreview] tabId:', tabId, 'tab exists:', !!tab, 'preview exists:', !!preview, 'content length:', tab?.content?.length);
 
         if (!tab || !preview) return;
 
         try {
             // Check if libraries are available
             if (!marked || !DOMPurify) {
+                console.error('[_renderPreview] Libraries not available:', { marked: !!marked, DOMPurify: !!DOMPurify });
                 preview.innerHTML = '<div class="preview-error"><div class="preview-error-icon">⚠️</div><div class="preview-error-title">Libraries Not Loaded</div><div class="preview-error-message">Required libraries (marked/DOMPurify) could not be loaded. Please check your installation.</div></div>';
                 return;
             }
+            console.log('[_renderPreview] About to call marked.parse, content length:', tab.content.length);
             const html = marked.parse(tab.content);
+            console.log('[_renderPreview] marked.parse returned type:', typeof html, 'isPromise:', html instanceof Promise);
+            if (html instanceof Promise) {
+                console.error('[_renderPreview] marked.parse returned a Promise! Need to await it.');
+                return;
+            }
             let sanitizedHtml = DOMPurify.sanitize(html);
+            console.log('[_renderPreview] DOMPurify.sanitize returned, length:', sanitizedHtml.length);
 
             // TOC generation
             if (sanitizedHtml.includes('[[toc]]') || sanitizedHtml.includes('[TOC]')) {