Fix: Correctly highlight active navigation link on scroll

The previous implementation had a logic flaw where the active navigation link would not be cleared correctly when scrolling between sections. This was because the `setActive` function was only called when a section was in view, but it was not cleared when no section was active.

This commit refactors the scroll event handler in `Navbar.tsx` to correctly identify the active section and clear the highlighting if no section is active, regardless of the scroll position. This ensures that the active link is always correctly highlighted.

Author: google-labs-jules[bot]

jules-scratch/verification/verify-about.png

@@ -0,0 +1,51 @@
+import re
+from playwright.sync_api import sync_playwright, Page, expect
+
+def run(playwright):
+    browser = playwright.chromium.launch(headless=True)
+    page = browser.new_page()
+
+    try:
+        # Navigate to the local development server
+        page.goto("http://localhost:5173")
+
+        # Wait for the page to load by waiting for a known element
+        page.wait_for_selector("section#about")
+
+        # --- Verify 'About' section ---
+        # Scroll to the 'about' section to trigger the highlighter
+        page.evaluate("document.querySelector('section#about').scrollIntoView()")
+        # Wait for scroll and potential UI update
+        page.wait_for_timeout(500)
+        # Check if the 'About' link is active
+        about_link = page.locator('//ul[contains(@class, "sm:flex")]//a[text()="About"]/parent::li')
+        expect(about_link).to_have_class(re.compile(r"\btext-white\b"))
+        page.screenshot(path="jules-scratch/verification/verify-about.png")
+
+        # --- Verify 'Work' section ---
+        page.evaluate("document.querySelector('section#work').scrollIntoView()")
+        page.wait_for_timeout(500)
+        work_link = page.locator('//ul[contains(@class, "sm:flex")]//a[text()="Work"]/parent::li')
+        expect(work_link).to_have_class(re.compile(r"\btext-white\b"))
+        page.screenshot(path="jules-scratch/verification/verify-work.png")
+
+        # --- Verify 'Contact' section ---
+        page.evaluate("document.querySelector('section#contact').scrollIntoView()")
+        page.wait_for_timeout(500)
+        contact_link = page.locator('//ul[contains(@class, "sm:flex")]//a[text()="Contact"]/parent::li')
+        expect(contact_link).to_have_class(re.compile(r"\btext-white\b"))
+        page.screenshot(path="jules-scratch/verification/verify-contact.png")
+
+        # --- Verify scrolling to top ---
+        page.evaluate("window.scrollTo(0, 0)")
+        page.wait_for_timeout(500)
+        # Check that all links are inactive (i.e., have text-secondary class)
+        inactive_links = page.locator('//ul[contains(@class, "sm:flex")]//li[contains(@class, "text-secondary")]')
+        expect(inactive_links).to_have_count(3)
+        page.screenshot(path="jules-scratch/verification/verify-top.png")
+
+    finally:
+        browser.close()
+
+with sync_playwright() as playwright:
+    run(playwright)

jules-scratch/verification/verify-contact.png

@@ -14,18 +14,10 @@ const Navbar = () => {
   useEffect(() => {
     const handleScroll = () => {
       const scrollTop = window.scrollY;
-      if (scrollTop > 100) {
-        setScrolled(true);
-      } else {
-        setScrolled(false);
-        setActive("");
-      }
-    };
-
-    window.addEventListener("scroll", handleScroll);
+      setScrolled(scrollTop > 100);
 
-    const navbarHighlighter = () => {
       const sections = document.querySelectorAll("section[id]");
+      let activeSectionId: string | null = null;
 
       sections.forEach((current) => {
         const sectionId = current.getAttribute("id");
@@ -35,16 +27,17 @@ const Navbar = () => {
           current.getBoundingClientRect().top - sectionHeight * 0.2;
 
         if (sectionTop < 0 && sectionTop + sectionHeight > 0) {
-          setActive(sectionId);
+          activeSectionId = sectionId;
         }
       });
+
+      setActive(activeSectionId || "");
     };
 
-    window.addEventListener("scroll", navbarHighlighter);
+    window.addEventListener("scroll", handleScroll);
 
     return () => {
       window.removeEventListener("scroll", handleScroll);
-      window.removeEventListener("scroll", navbarHighlighter);
     };
   }, []);