From c5a4a53bd6ffc10e5a93082fc1db7c6e68ad6b3a Mon Sep 17 00:00:00 2001
From: mdjfs <marcos.fuenmayorhtc@gmail.com>
Date: Tue, 19 Jul 2022 23:43:30 -0300
Subject: [PATCH] Add source line number attribute in order to allow sync
 scrolls

---
 lib/renderer.js | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/lib/renderer.js b/lib/renderer.js
index 268cf78..4cebea9 100644
--- a/lib/renderer.js
+++ b/lib/renderer.js
@@ -219,6 +219,19 @@ Renderer.prototype.renderToken = function renderToken(tokens, idx, options) {
   // Add token name, e.g. `<img`
   result += (token.nesting === -1 ? '</' : '<') + token.tag;
 
+  // Add source line number attribute in order to allow sync scrolls
+  // Idea extracted from (https://markdown-it.github.io/index.js)
+  if (options.lineNumber) {
+    if (token.map && token.level === 0) {
+      var attr = [ 'data-line', token.map[0] ];
+      if (token.attrs) {
+        token.attrs.push(attr);
+      } else {
+        token.attrs = [ attr ];
+      }
+    }
+  }
+
   // Encode attributes, e.g. `<img src="foo"`
   result += this.renderAttrs(token);