test: harden business boundary conditions

apps/server/src/bills/bills.boundaries.spec.ts

@@ -0,0 +1,77 @@
+import { BadRequestException, NotFoundException } from '@nestjs/common';
+import { BillsService } from './bills.service';
+import { Bill } from '../entities/bill.entity';
+
+function queryBuilder() {
+  return {
+    update: jest.fn().mockReturnThis(),
+    set: jest.fn().mockReturnThis(),
+    where: jest.fn().mockReturnThis(),
+    execute: jest.fn().mockResolvedValue({ affected: 1 }),
+  };
+}
+
+function createService(bills: Partial<Bill>[] = []) {
+  const billRepo = {
+    find: jest.fn().mockResolvedValue(bills),
+    findOne: jest.fn().mockResolvedValue(bills[0] ?? null),
+    save: jest.fn(async (value) => value),
+    createQueryBuilder: jest.fn(() => queryBuilder()),
+  };
+  const manager = {
+    delete: jest.fn(),
+    update: jest.fn(),
+  };
+  const dataSource = { transaction: jest.fn(async (callback) => callback(manager)) };
+  const service = new BillsService(
+    billRepo as any,
+    { delete: jest.fn() } as any,
+    {} as any,
+    { update: jest.fn() } as any,
+    {} as any,
+    {} as any,
+    dataSource as any,
+    {} as any,
+  );
+  return { service, billRepo, dataSource, manager };
+}
+
+describe('BillsService state and batch boundaries', () => {
+  it('rejects an empty batch status update', async () => {
+    const { service, billRepo } = createService();
+    await expect(service.batchUpdateStatus([], 'paid')).rejects.toBeInstanceOf(BadRequestException);
+    expect(billRepo.find).not.toHaveBeenCalled();
+  });
+
+  it('rejects a batch status update when some ids do not exist', async () => {
+    const { service, billRepo } = createService([{ id: 1, paidAmount: 0, outstandingAmount: 10 }]);
+    await expect(service.batchUpdateStatus([1, 2], 'unpaid')).rejects.toBeInstanceOf(NotFoundException);
+    expect(billRepo.createQueryBuilder).not.toHaveBeenCalled();
+  });
+
+  it('rejects marking a partially paid bill unpaid', async () => {
+    const { service, billRepo } = createService([{ id: 1, paidAmount: 10, outstandingAmount: 90, status: 'partially_paid' }]);
+    await expect(service.updateStatus(1, { status: 'unpaid' })).rejects.toBeInstanceOf(BadRequestException);
+    expect(billRepo.save).not.toHaveBeenCalled();
+  });
+
+  it('rejects an empty batch delete', async () => {
+    const { service, dataSource } = createService();
+    await expect(service.batchRemove([])).rejects.toBeInstanceOf(BadRequestException);
+    expect(dataSource.transaction).not.toHaveBeenCalled();
+  });
+
+  it('rejects a batch delete when some ids do not exist', async () => {
+    const { service, dataSource } = createService([{ id: 1, paidAmount: 0, status: 'unpaid' }]);
+    await expect(service.batchRemove([1, 2])).rejects.toBeInstanceOf(NotFoundException);
+    expect(dataSource.transaction).not.toHaveBeenCalled();
+  });
+
+  it('deletes a bill and its links in one transaction', async () => {
+    const { service, dataSource, manager } = createService([{ id: 1, paidAmount: 0, status: 'unpaid' }]);
+    await expect(service.remove(1)).resolves.toEqual({ message: '账单已删除' });
+    expect(dataSource.transaction).toHaveBeenCalledTimes(1);
+    expect(manager.delete).toHaveBeenCalledTimes(2);
+    expect(manager.update).toHaveBeenCalledTimes(1);
+  });
+});