feat: support shared pet care tasks and smooth daily page return

pets-be/internal/httpapi/tasks_test.go

@@ -47,6 +47,10 @@ func TestTaskCompletionPostgres(t *testing.T) {
 		t.Fatal(tx.Error)
 	}
 	defer tx.Rollback()
+	// Verify the nullable pet association migration without changing live schema.
+	if err := tx.AutoMigrate(&model.CareTask{}); err != nil {
+		t.Fatal(err)
+	}
 	user := model.User{OpenID: "completion-test:" + uuid.NewString(), Nickname: "测试家长"}
 	if err := tx.Create(&user).Error; err != nil {
 		t.Fatal(err)
@@ -55,11 +59,54 @@ func TestTaskCompletionPostgres(t *testing.T) {
 	if err := tx.Create(&pet).Error; err != nil {
 		t.Fatal(err)
 	}
-	tasks := []model.CareTask{{UserID: user.ID, PetID: pet.ID, Title: "喝水", Category: "water", TimeOfDay: "08:00", RepeatRule: "daily"}, {UserID: user.ID, PetID: pet.ID, Title: "喂食", Category: "food", TimeOfDay: "09:00", RepeatRule: "daily"}}
+	tasks := []model.CareTask{{UserID: user.ID, PetID: &pet.ID, Title: "喝水", Category: "water", TimeOfDay: "08:00", RepeatRule: "daily"}, {UserID: user.ID, PetID: &pet.ID, Title: "喂食", Category: "food", TimeOfDay: "09:00", RepeatRule: "daily"}}
 	if err := tx.Create(&tasks).Error; err != nil {
 		t.Fatal(err)
 	}
 	api := New(tx, nil, cfg)
+	request := func(method, route, id string, body gin.H, handler gin.HandlerFunc) *httptest.ResponseRecorder {
+		t.Helper()
+		encoded, _ := json.Marshal(body)
+		rec := httptest.NewRecorder()
+		c, _ := gin.CreateTestContext(rec)
+		c.Set("actor_id", user.ID)
+		c.Params = gin.Params{{Key: "id", Value: id}}
+		c.Request = httptest.NewRequest(method, route, bytes.NewReader(encoded))
+		handler(c)
+		return rec
+	}
+	allBody := gin.H{"all_pets": true, "title": "全部换水", "category": "water", "time_of_day": "10:00", "repeat_rule": "daily"}
+	rec := request("POST", "/tasks", "", allBody, api.createTask)
+	if rec.Code != 201 {
+		t.Fatalf("all-pet creation: %d %s", rec.Code, rec.Body.String())
+	}
+	var allTask model.CareTask
+	if err := tx.Where("user_id = ? AND title = ?", user.ID, "全部换水").First(&allTask).Error; err != nil || allTask.PetID != nil {
+		t.Fatalf("all-pet association should be null: %v", err)
+	}
+	// Single-pet filters include shared tasks; other users' tasks remain isolated.
+	rec = request("GET", "/tasks?date=2026-10-05&pet_id="+pet.ID, "", nil, api.listTasks)
+	var listing struct {
+		Data struct {
+			Items []struct {
+				ID      string `json:"id"`
+				AllPets bool   `json:"all_pets"`
+			} `json:"items"`
+		} `json:"data"`
+	}
+	if err := json.Unmarshal(rec.Body.Bytes(), &listing); err != nil || rec.Code != 200 || len(listing.Data.Items) != 3 {
+		t.Fatalf("pet filter omitted shared task: %s", rec.Body.String())
+	}
+	if rec = request("PUT", "/tasks/"+allTask.ID, allTask.ID, gin.H{"pet_id": pet.ID, "title": "单只换水"}, api.updateTask); rec.Code != 200 {
+		t.Fatalf("switch to single pet: %s", rec.Body.String())
+	}
+	if rec = request("PUT", "/tasks/"+allTask.ID, allTask.ID, allBody, api.updateTask); rec.Code != 200 {
+		t.Fatalf("switch to all pets: %s", rec.Body.String())
+	}
+	conflicting := gin.H{"all_pets": true, "pet_id": pet.ID, "title": "冲突选择"}
+	if rec = request("POST", "/tasks", "", conflicting, api.createTask); rec.Code != 400 {
+		t.Fatalf("ambiguous selection accepted: %s", rec.Body.String())
+	}
 	call := func(ids []string) int {
 		t.Helper()
 		body, _ := json.Marshal(gin.H{"date": "2026-10-05", "task_ids": ids})
@@ -88,4 +135,11 @@ func TestTaskCompletionPostgres(t *testing.T) {
 	if count != 2 {
 		t.Fatalf("retry duplicated completions: %d", count)
 	}
+	if status := call([]string{allTask.ID}); status != 200 {
+		t.Fatalf("all-pet completion status %d", status)
+	}
+	tx.Model(&model.TaskCompletion{}).Where("task_id = ?", allTask.ID).Count(&count)
+	if count != 1 {
+		t.Fatalf("shared task should have one completion: %d", count)
+	}
 }