add more edge case

Author: Pistonight

src/theme/toc.js.hbs

@@ -13,49 +13,75 @@ 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;
+        function isCurrentPage(href, current_page_for_comparison) {
+            if (!href) {
+                return false;
+            }
+            if (!current_page_for_comparison) {
+                current_page_for_comparison = current_page;
+            }
+            if (!current_page_for_comparison.endsWith(".html")) {
+                current_page_for_comparison += ".html";
             }
             if (href.endsWith("/")) {
                 href += "index.html";
             } else if (!href.endsWith(".html")) {
                 href += ".html";
             }
-            return current_page === href;
+            return current_page_for_comparison === href;
         }
 
+        function setActivePage(link) {
+            link.classList.add("active");
+            var parent = link.parentElement;
+            if (parent && parent.classList.contains("chapter-item")) {
+                parent.classList.add("expanded");
+            }
+            while (parent) {
+                if (parent.tagName === "LI" && parent.previousElementSibling) {
+                    if (parent.previousElementSibling.classList.contains("chapter-item")) {
+                        parent.previousElementSibling.classList.add("expanded");
+                    }
+                }
+                parent = parent.parentElement;
+            }
+        }
+
+        let foundActivePage = false;
+        var l = links.length;
         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 (isCurrentPage(i)) {
-                link.classList.add("active");
-                var parent = link.parentElement;
-                if (parent && parent.classList.contains("chapter-item")) {
-                    parent.classList.add("expanded");
-                }
-                while (parent) {
-                    if (parent.tagName === "LI" && parent.previousElementSibling) {
-                        if (parent.previousElementSibling.classList.contains("chapter-item")) {
-                            parent.previousElementSibling.classList.add("expanded");
-                        }
+            if (isCurrentPage(link.href) || (i === 0 && path_to_root === "" && current_page.endsWith("/index.html"))) {
+                foundActivePage = true;
+                setActivePage(link);
+            }
+        }
+
+        if (!foundActivePage) {
+            // If the current page is not found, there is a possibility
+            // that the service has redirected /foo/index.html to /foo (without the trailing slash)
+            // try to find the active page again using this fallback
+            if (!current_page.endsWith(".html") && !current_page.endsWith("/")) {
+                let current_page_fallback = current_page + "/index.html";
+                let l = links.length;
+                for (let i = 0; i < l; ++i) {
+                    let link = links[i];
+                    if (isCurrentPage(link.href, current_page_fallback)) {
+                        setActivePage(link);
+                        break;
                     }
-                    parent = parent.parentElement;
                 }
             }
         }
+
         // Track and set sidebar scroll position
         this.addEventListener('click', function(e) {
             if (e.target.tagName === 'A') {