fix(assistant): #91 question positionnee au bord haut de la fenetre (padding dynamique, overflow-anchor, passe de correction)

2026-09-15 20:29:01 -04:00
parent 1ed0d52619
commit daf9ff3b2d
6 changed files with 130 additions and 24 deletions
@@ -235,6 +235,45 @@ async function main() {
      panel.remove();
    });

+    await test("a short answer still rolls the post up: bottom padding is grown", () => {
+      // jsdom has no layout, so the geometry is stubbed: the post sits 500px
+      // down the thread while only 300px of scroll room exist. Without the
+      // padding trick the browser clamps and the post stops mid-window.
+      const b = new BooksLM();
+      b._messages = [
+        { role: "user", content: "question" },
+        { role: "assistant", content: "réponse courte" },
+      ];
+      const panel = document.createElement("div");
+      panel.innerHTML = `<div class="bookslm-messages"></div>`;
+      document.body.appendChild(panel);
+      b._panel = panel;
+      const raf = globalThis.requestAnimationFrame;
+      globalThis.requestAnimationFrame = (fn) => fn();
+      try {
+        // Render the messages, then fake the geometry and re-anchor.
+        b._renderMessages();
+        const c = panel.querySelector(".bookslm-messages");
+        const post = panel.querySelector(".bookslm-msg.user");
+        Object.defineProperty(c, "clientHeight", { value: 400, configurable: true });
+        Object.defineProperty(c, "scrollHeight", { value: 700, configurable: true, writable: true });
+        c.getBoundingClientRect = () => ({ top: 0, left: 0, right: 0, bottom: 400, width: 400, height: 400 });
+        post.getBoundingClientRect = () => ({ top: 500, left: 0, right: 0, bottom: 560, width: 300, height: 60 });
+        b._anchorLatestUser({ instant: true });
+        // target (500) - max (300) = 200px of missing room.
+        assert.equal(c.style.paddingBottom, "200px", "padding grown by the missing room");
+
+        // Plenty of room below the post → no padding at all.
+        Object.defineProperty(c, "scrollHeight", { value: 2000, configurable: true, writable: true });
+        c.scrollTop = 0;
+        b._anchorLatestUser({ instant: true });
+        assert.equal(c.style.paddingBottom, "", "no padding when the thread already scrolls far enough");
+      } finally {
+        globalThis.requestAnimationFrame = raf;
+        panel.remove();
+      }
+    });
+
    await test("the placeholder render keeps the anchor (no scroll reset before first token)", async () => {
      // Regression: the assistant placeholder used to be rendered while
      // `_isLoading` was still false, so it took the "restore previous