make condition to add mark active page in toc looser

Author: Pistonight

src/theme/toc.js.hbs

@@ -13,17 +13,34 @@ class MDBookSidebarScrollbox extends HTMLElement {
         let current_page = document.location.href.toString().split("#")[0];
         if (current_page.endsWith("/")) {
             current_page += "index.html";
+        } else if (!current_page.endsWith(".html")) {
+            current_page += ".html";
         }
         var links = Array.prototype.slice.call(this.querySelectorAll("a"));
         var l = links.length;
+        
+        function isCurrentPage(i) {
+            let href = links[i].href;
+            // special case for root
+            if (i === 0 && path_to_root === "" && current_page.endsWith("/index.html")) {
+                return true;
+            }
+            if (href.endsWith("/")) {
+                href += "index.html";
+            } else if (!href.endsWith(".html")) {
+                href += ".html";
+            }
+            return current_page === href;
+        }
+
         for (var i = 0; i < l; ++i) {
             var link = links[i];
             var href = link.getAttribute("href");
             if (href && !href.startsWith("#") && !/^(?:[a-z+]+:)?\/\//.test(href)) {
                 link.href = path_to_root + href;
             }
             // The "index" page is supposed to alias the first chapter in the book.
-            if (link.href === current_page || (i === 0 && path_to_root === "" && current_page.endsWith("/index.html"))) {
+            if (isCurrentPage(i)) {
                 link.classList.add("active");
                 var parent = link.parentElement;
                 if (parent && parent.classList.contains("chapter-item")) {