feat: prefetch the next mobile update (Closes #757)

tests/test_frontend_bundle.py

@@ -68,8 +68,8 @@ def test_product_workflows_are_stable_lazy_feature_chunks(tmp_path):
     assert b"function attachSecurityCenter" in security_center.runtime_bytes
     assert b"gitea_time_logged" not in first.runtime_bytes
     assert b"gitea_time_logged" in security_center.runtime_bytes
-    # The recap adds only startup wiring; its UI remains in the lazy Today bundle.
-    assert len(first.runtime_gzip_bytes) <= 96 * 1024
+    # One-ahead Updates prefetch stays in the core reader so transitions can reuse its in-flight request.
+    assert len(first.runtime_gzip_bytes) <= 97 * 1024
     assert f'name="stackchain-feature-issue-capture" content="{capture.runtime_name}"' in first.dashboard_html
     assert f'name="stackchain-feature-pull-workflow" content="{pull_workflow.runtime_name}"' in first.dashboard_html
     assert f"BASE + '{capture.runtime_name}'" in first.service_worker_source

tests/test_my_work.py

@@ -4871,6 +4871,76 @@ reader.open(original[0], original).then(() =>
     assert output["result"]["next"]["notification_id"] == 43
 
 
+def test_notification_reader_consumes_one_bounded_prefetch_without_duplicate_load():
+    script = f"""
+const buildMyWork = require({json.dumps(str(MY_WORK))});
+const items = [1,2,3].map(notification_id => ({{kind:'update', notification_id, has_update:true}}));
+const loaded = [], details = [], statuses = [];
+const releases = {{}};
+const reader = buildMyWork.createNotificationReader({{
+  load: id => {{
+    loaded.push(id);
+    if (id === 1) return Promise.resolve({{id}});
+    return new Promise(resolve => {{ releases[id] = resolve; }});
+  }},
+  markRead: async () => {{}},
+  onOpen: () => {{}}, onDetail: detail => details.push(detail.id), onItems: () => {{}},
+  onStatus: status => statuses.push(status), onClose: () => {{}},
+}});
+(async () => {{
+  await reader.open(items[0]);
+  const first = reader.prefetch(items[1]);
+  const duplicate = reader.prefetch(items[1]);
+  const rejected = reader.prefetch(items[2]);
+  const advancing = reader.open(items[1]);
+  await Promise.resolve();
+  releases[2]({{id:2}});
+  await advancing;
+  process.stdout.write(JSON.stringify({{
+    loaded, details, same:first === duplicate, rejected, statuses,
+  }}));
+}})();
+"""
+    output = json.loads(subprocess.run(
+        ["node", "-e", script], check=True, capture_output=True, text=True
+    ).stdout)
+
+    assert output == {
+        "loaded": [1, 2],
+        "details": [1, 2],
+        "same": True,
+        "rejected": False,
+        "statuses": ["Loading update…", "Update ready.", "Update ready."],
+    }
+
+
+def test_notification_reader_never_consumes_prefetch_from_another_account_scope():
+    script = f"""
+const buildMyWork = require({json.dumps(str(MY_WORK))});
+let scope = 'timmy';
+const loaded = [];
+const reader = buildMyWork.createNotificationReader({{
+  load: async id => {{ loaded.push([scope, id]); return {{owner:scope, id}}; }},
+  getScope: () => scope,
+  markRead: async () => {{}}, onOpen: () => {{}}, onItems: () => {{}}, onStatus: () => {{}},
+  onDetail: detail => {{ if (detail.owner !== scope) throw new Error('cross-account detail'); }},
+  onClose: () => {{}},
+}});
+(async () => {{
+  await reader.open({{notification_id:1}});
+  await reader.prefetch({{notification_id:2}});
+  scope = 'alexander';
+  const opened = await reader.open({{notification_id:2}});
+  process.stdout.write(JSON.stringify({{loaded, opened}}));
+}})();
+"""
+    output = json.loads(subprocess.run(
+        ["node", "-e", script], check=True, capture_output=True, text=True
+    ).stdout)
+
+    assert output == {"loaded": [["timmy", 1], ["timmy", 2], ["alexander", 2]], "opened": True}
+
+
 def test_notification_reader_acknowledges_once_and_opens_next_update():
     script = f"""
 const buildMyWork = require({json.dumps(str(MY_WORK))});

tests/test_update_triage_session.py

@@ -81,6 +81,27 @@ process.stdout.write(JSON.stringify({opened, progress, stored:values.get('stackc
     }
 
 
+def test_update_triage_exposes_only_the_next_surviving_snapshot_item():
+    result = run_session("""
+const values = new Map();
+let items = [1,2,3].map(notification_id => ({notification_id}));
+const session = createSession({
+  storage:{getItem:key=>values.get(key)||null,setItem:(key,value)=>values.set(key,value),removeItem:key=>values.delete(key)},
+  getLogin:()=> 'timmy', getItems:()=>items,
+  onOpen:()=>{}, onProgress:()=>{}, onFinish:()=>{},
+});
+session.start();
+const first = session.next()?.notification_id;
+items = [1,3,4].map(notification_id => ({notification_id}));
+const afterRemoval = session.next()?.notification_id;
+session.keepUnreadAndNext();
+const afterAdvance = session.next();
+process.stdout.write(JSON.stringify({first, afterRemoval, afterAdvance:afterAdvance || null}));
+""")
+
+    assert result == {"first": 2, "afterRemoval": 3, "afterAdvance": None}
+
+
 @pytest.mark.anyio
 async def test_dashboard_wires_resumable_updates_triage_mobile_flow():
     html = await dashboard()