test: harden business boundary conditions

apps/server/src/expenses/dto/expense.dto.spec.ts

@@ -0,0 +1,31 @@
+import 'reflect-metadata';
+import { plainToInstance } from 'class-transformer';
+import { validate } from 'class-validator';
+import { BatchRoomExpenseDto } from './expense.dto';
+
+describe('BatchRoomExpenseDto boundaries', () => {
+  it.each([
+    { expenses: [] },
+    { expenses: [{ roomId: 1, expenseType: 'water', amount: 0 }] },
+    { expenses: [{ roomId: 1, expenseType: 'water', amount: -1 }] },
+    { expenses: [{ roomId: 1, expenseType: 'water', amount: 1.001 }] },
+    { periodStart: '2026-02-31' },
+  ])('rejects invalid batch payload %#', async (override) => {
+    const dto = plainToInstance(BatchRoomExpenseDto, {
+      periodStart: '2026-07-01',
+      periodEnd: '2026-07-31',
+      expenses: [{ roomId: 1, expenseType: 'water', amount: 10 }],
+      ...override,
+    });
+    await expect(validate(dto)).resolves.not.toHaveLength(0);
+  });
+
+  it('accepts a valid batch payload', async () => {
+    const dto = plainToInstance(BatchRoomExpenseDto, {
+      periodStart: '2026-07-01',
+      periodEnd: '2026-07-31',
+      expenses: [{ roomId: 1, expenseType: 'water', amount: 10.25 }],
+    });
+    await expect(validate(dto)).resolves.toHaveLength(0);
+  });
+});

apps/server/src/expenses/dto/expense.dto.ts

@@ -1,4 +1,4 @@
-import { IsDateString, IsIn, IsInt, IsString, IsNumber, IsOptional, Matches, Min } from 'class-validator';
+import { ArrayNotEmpty, IsArray, IsDateString, IsIn, IsInt, IsISO8601, IsString, IsNumber, IsOptional, Matches, Min, ValidateNested } from 'class-validator';
 import { PartialType } from '@nestjs/mapped-types';
 import { Type } from 'class-transformer';
 
@@ -13,9 +13,13 @@ export class CreateRoomExpenseDto {
   @Min(0.01)
   amount: number;
 
+  @Matches(/^\d{4}-\d{2}-\d{2}$/)
+  @IsISO8601({ strict: true })
   @IsDateString()
   periodStart: string;
 
+  @Matches(/^\d{4}-\d{2}-\d{2}$/)
+  @IsISO8601({ strict: true })
   @IsDateString()
   periodEnd: string;
 
@@ -39,6 +43,8 @@ export class CreatePersonalExpenseDto {
   @Min(0.01)
   amount: number;
 
+  @Matches(/^\d{4}-\d{2}-\d{2}$/)
+  @IsISO8601({ strict: true })
   @IsDateString()
   expenseDate: string;
 
@@ -74,14 +80,38 @@ export class QueryPersonalExpenseDto {
   studentId?: number;
 }
 
-export class BatchRoomExpenseDto {
+export class BatchRoomExpenseItemDto {
+  @IsInt()
+  roomId: number;
+
   @IsString()
+  expenseType: string;
+
+  @IsNumber({ maxDecimalPlaces: 2 })
+  @Min(0.01)
+  amount: number;
+
+  @IsOptional()
+  @IsString()
+  description?: string;
+}
+
+export class BatchRoomExpenseDto {
+  @Matches(/^\d{4}-\d{2}-\d{2}$/)
+  @IsISO8601({ strict: true })
+  @IsDateString()
   periodStart: string;
 
-  @IsString()
+  @Matches(/^\d{4}-\d{2}-\d{2}$/)
+  @IsISO8601({ strict: true })
+  @IsDateString()
   periodEnd: string;
 
-  expenses: { roomId: number; expenseType: string; amount: number; description?: string }[];
+  @IsArray()
+  @ArrayNotEmpty()
+  @ValidateNested({ each: true })
+  @Type(() => BatchRoomExpenseItemDto)
+  expenses: BatchRoomExpenseItemDto[];
 }