feat: show tasks completed today

tests/test_app.py

@@ -1,6 +1,7 @@
 import base64
 import json
 import os
+from datetime import UTC, datetime
 from uuid import UUID
 
 from fastapi.testclient import TestClient
@@ -83,8 +84,17 @@ def test_task_can_be_updated_completed_and_soft_deleted(client):
     assert updated.status_code == 200
     assert updated.json()["title"] == "新标题"
     assert updated.json()["completed"] is True
+    assert updated.json()["completed_at"] is not None
     assert updated.json()["version"] == 2
 
+    reopened = client.patch(
+        f"/api/v1/tasks/{task['id']}",
+        json={"completed": False, "version": updated.json()["version"]},
+    )
+    assert reopened.status_code == 200
+    assert reopened.json()["completed"] is False
+    assert reopened.json()["completed_at"] is None
+
     conflict = client.patch(
         f"/api/v1/tasks/{task['id']}",
         json={"title": "冲突标题", "version": task["version"]},
@@ -119,6 +129,105 @@ def test_reorder_tasks_persists_top_level_and_subtask_order(client):
     assert [task["title"] for task in listed[1]["subtasks"]] == ["子任务 B", "子任务 A"]
 
 
+def test_today_list_includes_tasks_completed_today_even_if_due_earlier(client, monkeypatch):
+    client = initialized_client(client)
+    inbox = client.get("/api/v1/lists").json()[0]
+    overdue = client.post(
+        "/api/v1/tasks",
+        json={"title": "昨天截止今天完成", "list_id": inbox["id"], "due_at": "2026-09-14T02:00:00Z"},
+    ).json()
+    today_due = client.post(
+        "/api/v1/tasks",
+        json={"title": "今天截止今天完成", "list_id": inbox["id"], "due_at": "2026-09-15T02:00:00Z"},
+    ).json()
+    client.post(
+        "/api/v1/tasks",
+        json={"title": "今天未完成", "list_id": inbox["id"], "due_at": "2026-09-15T10:00:00Z"},
+    ).json()
+
+    completed_at = datetime(2026, 9, 15, 3, 30, tzinfo=UTC)
+    monkeypatch.setattr("backend.recurrence_service.utcnow", lambda: completed_at)
+    monkeypatch.setattr("backend.main.utcnow", lambda: completed_at)
+
+    completed_overdue = client.patch(
+        f"/api/v1/tasks/{overdue['id']}",
+        json={"completed": True, "version": overdue["version"]},
+    )
+    assert completed_overdue.status_code == 200
+    assert datetime.fromisoformat(completed_overdue.json()["completed_at"]) == completed_at
+
+    completed_today = client.patch(
+        f"/api/v1/tasks/{today_due['id']}",
+        json={"completed": True, "version": today_due["version"]},
+    )
+    assert completed_today.status_code == 200
+    assert datetime.fromisoformat(completed_today.json()["completed_at"]) == completed_at
+
+    today = client.get(
+        "/api/v1/tasks",
+        params={
+            "due_from": "2026-09-15T00:00:00Z",
+            "due_to": "2026-09-16T00:00:00Z",
+            "completed_from": "2026-09-15T00:00:00Z",
+            "completed_to": "2026-09-16T00:00:00Z",
+        },
+    )
+    assert today.status_code == 200
+    assert {item["title"] for item in today.json()["items"]} == {"昨天截止今天完成", "今天截止今天完成", "今天未完成"}
+
+    hidden_completed = client.get(
+        "/api/v1/tasks",
+        params={
+            "due_from": "2026-09-15T00:00:00Z",
+            "due_to": "2026-09-16T00:00:00Z",
+            "completed": False,
+        },
+    )
+    assert hidden_completed.status_code == 200
+    assert [item["title"] for item in hidden_completed.json()["items"]] == ["今天未完成"]
+
+    shown_completed = client.get(
+        "/api/v1/tasks",
+        params={
+            "due_from": "2026-09-15T00:00:00Z",
+            "due_to": "2026-09-16T00:00:00Z",
+            "completed": True,
+            "completed_from": "2026-09-15T00:00:00Z",
+            "completed_to": "2026-09-16T00:00:00Z",
+        },
+    )
+    assert shown_completed.status_code == 200
+    assert {item["title"] for item in shown_completed.json()["items"]} == {"昨天截止今天完成", "今天截止今天完成"}
+
+
+def test_batch_complete_records_completed_at(client, monkeypatch):
+    client = initialized_client(client)
+    inbox = client.get("/api/v1/lists").json()[0]
+    first = client.post("/api/v1/tasks", json={"title": "批量1", "list_id": inbox["id"]}).json()
+    second = client.post("/api/v1/tasks", json={"title": "批量2", "list_id": inbox["id"]}).json()
+    completed_at = datetime(2026, 9, 15, 6, 0, tzinfo=UTC)
+    monkeypatch.setattr("backend.recurrence_service.utcnow", lambda: completed_at)
+    monkeypatch.setattr("backend.main.utcnow", lambda: completed_at)
+
+    response = client.post(
+        "/api/v1/tasks/batch",
+        json={
+            "task_ids": [first["id"], second["id"]],
+            "completed": True,
+            "versions": {first["id"]: first["version"], second["id"]: second["version"]},
+        },
+    )
+    assert response.status_code == 200
+
+    listed = client.get("/api/v1/tasks", params={"completed": True}).json()["items"]
+    completed_map = {
+        item["title"]: datetime.fromisoformat(item["completed_at"])
+        for item in listed
+        if item["title"] in {"批量1", "批量2"}
+    }
+    assert completed_map == {"批量1": completed_at, "批量2": completed_at}
+
+
 def test_reorder_tasks_rejects_mixed_parent_scopes_and_lists(client):
     client = initialized_client(client)
     inbox = client.get("/api/v1/lists").json()[0]