foodie-server/ruoyi-system/src/test/java/com/ruoyi/system/service/impl/PromotionCouponBatchServiceImplDiscountLimitTest.java

package com.ruoyi.system.service.impl;

import com.ruoyi.common.exception.ServiceException;
import com.ruoyi.system.domain.PromotionCouponBatch;
import com.ruoyi.system.domain.PromotionCouponRule;
import com.ruoyi.system.mapper.PosFoodMapper;
import com.ruoyi.system.mapper.PromotionCouponBatchMapper;
import com.ruoyi.system.mapper.PromotionCouponRuleMapper;
import com.ruoyi.system.service.ISysConfigService;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;
import org.springframework.test.util.ReflectionTestUtils;

import java.math.BigDecimal;

import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyNoInteractions;
import static org.mockito.Mockito.when;

@ExtendWith(MockitoExtension.class)
class PromotionCouponBatchServiceImplDiscountLimitTest {

    @Mock
    private PromotionCouponBatchMapper batchMapper;

    @Mock
    private PromotionCouponRuleMapper ruleMapper;

    @Mock
    private ISysConfigService configService;

    @Mock
    private PosFoodMapper posFoodMapper;

    private PromotionCouponBatchServiceImpl service;

    @BeforeEach
    void setUp() {
        when(configService.selectConfigByKey("promotion.discount.limit.enabled"))
                .thenReturn("true");
        when(configService.selectConfigByKey("promotion.discount.limit.ratio"))
                .thenReturn("20");
        PromotionDiscountLimitChecker checker = new PromotionDiscountLimitChecker();
        ReflectionTestUtils.setField(checker, "configService", configService);
        ReflectionTestUtils.setField(checker, "posFoodMapper", posFoodMapper);
        service = new PromotionCouponBatchServiceImpl();
        ReflectionTestUtils.setField(service, "promotionCouponBatchMapper", batchMapper);
        ReflectionTestUtils.setField(service, "ruleMapper", ruleMapper);
        ReflectionTestUtils.setField(service, "discountLimitChecker", checker);
    }

    @Test
    void createRejectsOverLimitCouponBeforeAnyDatabaseWrite() {
        PromotionCouponBatch batch = batch(null, 1, 100, 0);
        PromotionCouponRule rule = fullReductionRule("100", "21");

        assertThrows(ServiceException.class, () -> service.createBatch(batch, rule));

        verifyNoInteractions(batchMapper, ruleMapper);
    }

    @Test
    void unreceivedCouponUpdateRejectsOverLimitRuleBeforeReplacingStoredData() {
        PromotionCouponBatch existing = batch(7L, 1, 100, 0);
        existing.setStatus(0);
        existing.setRemainCount(100);
        when(batchMapper.selectById(7L)).thenReturn(existing);
        PromotionCouponBatch update = batch(7L, null, 100, null);

        assertThrows(ServiceException.class,
                () -> service.updateBatch(update, fullReductionRule("100", "21")));

        verify(batchMapper).selectById(7L);
        verify(batchMapper, never()).updateById(any(PromotionCouponBatch.class));
        verifyNoInteractions(ruleMapper);
    }

    private PromotionCouponBatch batch(Long id, Integer type, Integer totalCount,
                                       Integer receivedCount) {
        PromotionCouponBatch batch = new PromotionCouponBatch();
        batch.setId(id);
        batch.setCouponType(type);
        batch.setTotalCount(totalCount);
        batch.setReceivedCount(receivedCount);
        return batch;
    }

    private PromotionCouponRule fullReductionRule(String threshold, String amount) {
        PromotionCouponRule rule = new PromotionCouponRule();
        rule.setThreshold(new BigDecimal(threshold));
        rule.setAmount(new BigDecimal(amount));
        return rule;
    }
}