From 61b8c264a28edfb469fd45748fb902acd8055ba1 Mon Sep 17 00:00:00 2001
From: foxton9 <hansfoxton@gmail.com>
Date: Sun, 8 Dec 2024 23:18:16 +0800
Subject: [PATCH] add early return in init for no entry in TOC

---
 src/components/widget/TOC.astro | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/src/components/widget/TOC.astro b/src/components/widget/TOC.astro
index 1488f94de..8ac3e5aff 100644
--- a/src/components/widget/TOC.astro
+++ b/src/components/widget/TOC.astro
@@ -75,7 +75,7 @@ class TableOfContents extends HTMLElement {
         this.observer = new IntersectionObserver(
             this.markVisibleSection, { threshold: 0 }
         );
-    }
+    };
 
     markVisibleSection = (entries: IntersectionObserverEntry[]) => {
         entries.forEach((entry) => {
@@ -85,7 +85,7 @@ class TableOfContents extends HTMLElement {
                 this.active[idx] = entry.isIntersecting;
 
             if (entry.isIntersecting && this.anchorNavTarget == entry.target.firstChild)
-                this.anchorNavTarget = null;            
+                this.anchorNavTarget = null;
         });
 
         if (!this.active.includes(true))
@@ -152,7 +152,7 @@ class TableOfContents extends HTMLElement {
             this.scrollToActiveHeading();
             // });
         });
-    }
+    };
 
     fallback = () => {
         if (!this.sections.length) return;
@@ -172,7 +172,7 @@ class TableOfContents extends HTMLElement {
 
     markActiveHeading = (idx: number)=> {
         this.active[idx] = true;
-    }
+    };
 
     handleAnchorClick = (event: Event) => {
         const anchor = event
@@ -192,7 +192,7 @@ class TableOfContents extends HTMLElement {
 
     isInRange(value: number, min: number, max: number) {
         return min < value && value < max;
-    }
+    };
 
     connectedCallback() {
         // wait for the onload animation to finish, which makes the `getBoundingClientRect` return correct values
@@ -204,7 +204,7 @@ class TableOfContents extends HTMLElement {
         } else {
             console.warn('Animation element not found');
         }
-    }
+    };
 
     init() {
         this.tocEl = document.getElementById(
@@ -223,6 +223,8 @@ class TableOfContents extends HTMLElement {
             document.querySelectorAll<HTMLAnchorElement>("#toc a[href^='#']")
         );
 
+        if (this.tocEntries.length === 0) return;
+
         this.sections = new Array(this.tocEntries.length);
         this.headings = new Array(this.tocEntries.length);
         for (let i = 0; i < this.tocEntries.length; i++) {
@@ -243,7 +245,7 @@ class TableOfContents extends HTMLElement {
 
         this.fallback();
         this.update();
-    }
+    };
 
     disconnectedCallback() {
         this.sections.forEach((section) =>
@@ -251,7 +253,7 @@ class TableOfContents extends HTMLElement {
         );
         this.observer.disconnect();
         this.tocEl?.removeEventListener("click", this.handleAnchorClick);
-    }
+    };
 }
 
 customElements.define("table-of-contents", TableOfContents);