Update

tests/e2e/feed.py

@@ -917,3 +917,45 @@ def test_feed_online_now_widget_lists_current_user(alice):
         page.locator(f".online-user[title='{user['username']}']")
     ).to_have_count(1)
     expect(page.locator(".online-users .presence-dot.online").first).to_be_visible()
+
+
+def _scroll_and_open_post(page):
+    _seed_feed_posts(30)
+    page.goto(f"{BASE_URL}/feed", wait_until="domcontentloaded")
+    page.locator(".post-card").first.wait_for(state="visible")
+    page.evaluate("window.scrollTo(0, 1200)")
+    page.wait_for_function("window.scrollY > 1000")
+    card_link = page.locator(".post-card .card-link").nth(5)
+    card_link.scroll_into_view_if_needed()
+    page.wait_for_timeout(400)
+    y_before = page.evaluate("window.scrollY")
+    assert y_before > 0
+    card_link.click()
+    page.wait_for_url(f"{BASE_URL}/posts/*", wait_until="domcontentloaded")
+    return y_before
+
+
+def test_feed_scroll_restored_via_back_link(alice):
+    page, user = alice
+    y_before = _scroll_and_open_post(page)
+    back = page.locator("a.back-link")
+    back.wait_for(state="visible")
+    back.click()
+    page.wait_for_url(f"{BASE_URL}/feed*", wait_until="domcontentloaded")
+    page.wait_for_function(f"Math.abs(window.scrollY - {y_before}) < 60")
+
+
+def test_feed_scroll_restored_via_browser_back(alice):
+    page, user = alice
+    y_before = _scroll_and_open_post(page)
+    page.go_back(wait_until="domcontentloaded")
+    page.wait_for_function(f"Math.abs(window.scrollY - {y_before}) < 60")
+
+
+def test_feed_scroll_not_restored_on_fresh_visit(alice):
+    page, user = alice
+    _scroll_and_open_post(page)
+    page.goto(f"{BASE_URL}/gists", wait_until="domcontentloaded")
+    page.goto(f"{BASE_URL}/feed", wait_until="domcontentloaded")
+    page.wait_for_timeout(600)
+    assert page.evaluate("window.scrollY") < 60