Wow 2.6.0 发布，让领域驱动设计变得触手可得

多元共进｜2023 Google 开发者大会精彩演讲回顾

基于 DDD、EventSourcing 的现代响应式 CQRS 架构微服务开发框架

Spring WebFlux 集成

自动注册命令路由处理函数 (HandlerFunction) ，开发人员仅需编写领域模型，即可完成服务开发。

测试套件：80%+ 的测试覆盖率轻而易举

Given -> When -> Expect .

前置条件

理解 领域驱动设计：《实现领域驱动设计》、《领域驱动设计：软件核心复杂性应对之道》
理解 命令查询职责分离（CQRS）
理解 事件溯源架构
理解 响应式编程

特性

Aggregate Modeling
- Single Class
- Inheritance Pattern
- Aggregation Pattern
Saga Modeling
- StatelessSaga
Test Suite
- 兼容性测试规范（TCK）
- AggregateVerifier
- SagaVerifier
EventSourcing
- EventStore
  - MongoDB (Recommend)
  - R2dbc
    - Database Sharding
    - Table Sharding
  - Redis
- Snapshot
  - MongoDB
  - R2dbc
    - Database Sharding
    - Table Sharding
  - ElasticSearch
  - Redis (Recommend)
命令等待策略（WaitStrategy）
- SENT : 命令发送成功后发送完成信号
- PROCESSED : 命令处理完成后发送完成信号
- SNAPSHOT : 快照生成完成后发送完成信号
- PROJECTED : 命令产生的事件被投影后发送完成信号
CommandBus
- InMemoryCommandBus
- KafkaCommandBus (Recommend)
- RedisCommandBus
- LocalFirstCommandBus
DomainEventBus
- InMemoryDomainEventBus
- KafkaDomainEventBus (Recommend)
- RedisDomainEventBus
- LocalFirstDomainEventBus
StateEventBus
- InMemoryStateEventBus
- KafkaStateEventBus (Recommend)
- RedisStateEventBus
- LocalFirstStateEventBus
Spring 集成
- Spring Boot Auto Configuration
- Automatically register CommandAggregate to RouterFunction
可观测性
- OpenTelemetry
OpenAPI
WowMetadata Generator
- wow-compiler

Example

单元测试套件

80%+ 的测试覆盖率轻而易举。

Given -> When -> Expect .

Aggregate Unit Test (`AggregateVerifier`)

Aggregate Test

 internal class OrderTest {      private fun mockCreateOrder(): VerifiedStage<OrderState> {         val tenantId = GlobalIdGenerator.generateAsString()         val customerId = GlobalIdGenerator.generateAsString()          val orderItem = OrderItem(             GlobalIdGenerator.generateAsString(),             GlobalIdGenerator.generateAsString(),             BigDecimal.valueOf(10),             10,         )         val orderItems = listOf(orderItem)         val inventoryService = object : InventoryService {             override fun getInventory(productId: String): Mono<Int> {                 return orderItems.filter { it.productId == productId }.map { it.quantity }.first().toMono()             }         }         val pricingService = object : PricingService {             override fun getProductPrice(productId: String): Mono<BigDecimal> {                 return orderItems.filter { it.productId == productId }.map { it.price }.first().toMono()             }         }         return aggregateVerifier<Order, OrderState>(tenantId = tenantId)             .inject(DefaultCreateOrderSpec(inventoryService, pricingService))             .given()             .`when`(CreateOrder(customerId, orderItems, SHIPPING_ADDRESS, false))             .expectEventCount(1)             .expectEventType(OrderCreated::class.java)             .expectStateAggregate {                 assertThat(it.aggregateId.tenantId, equalTo(tenantId))             }             .expectState {                 assertThat(it.id, notNullValue())                 assertThat(it.customerId, equalTo(customerId))                 assertThat(it.address, equalTo(SHIPPING_ADDRESS))                 assertThat(it.items, equalTo(orderItems))                 assertThat(it.status, equalTo(OrderStatus.CREATED))             }             .verify()     }      /**      * 创建订单      */     @Test     fun createOrder() {         mockCreateOrder()     }      @Test     fun createOrderGivenEmptyItems() {         val customerId = GlobalIdGenerator.generateAsString()         aggregateVerifier<Order, OrderState>()             .inject(mockk<CreateOrderSpec>(), "createOrderSpec")             .given()             .`when`(CreateOrder(customerId, listOf(), SHIPPING_ADDRESS, false))             .expectErrorType(IllegalArgumentException::class.java)             .expectStateAggregate {                 /*                  * 该聚合对象处于未初始化状态，即该聚合未创建成功.                  */                 assertThat(it.initialized, equalTo(false))             }.verify()     }      /**      * 创建订单-库存不足      */     @Test     fun createOrderWhenInventoryShortage() {         val customerId = GlobalIdGenerator.generateAsString()         val orderItem = OrderItem(             GlobalIdGenerator.generateAsString(),             GlobalIdGenerator.generateAsString(),             BigDecimal.valueOf(10),             10,         )         val orderItems = listOf(orderItem)         val inventoryService = object : InventoryService {             override fun getInventory(productId: String): Mono<Int> {                 return orderItems.filter { it.productId == productId }                     /*                      * 模拟库存不足                      */                     .map { it.quantity - 1 }.first().toMono()             }         }         val pricingService = object : PricingService {             override fun getProductPrice(productId: String): Mono<BigDecimal> {                 return orderItems.filter { it.productId == productId }.map { it.price }.first().toMono()             }         }          aggregateVerifier<Order, OrderState>()             .inject(DefaultCreateOrderSpec(inventoryService, pricingService))             .given()             .`when`(CreateOrder(customerId, orderItems, SHIPPING_ADDRESS, false))             /*              * 期望：库存不足异常.              */             .expectErrorType(InventoryShortageException::class.java)             .expectStateAggregate {                 /*                  * 该聚合对象处于未初始化状态，即该聚合未创建成功.                  */                 assertThat(it.initialized, equalTo(false))             }.verify()     }      /**      * 创建订单-下单价格与当前价格不一致      */     @Test     fun createOrderWhenPriceInconsistency() {         val customerId = GlobalIdGenerator.generateAsString()         val orderItem = OrderItem(             GlobalIdGenerator.generateAsString(),             GlobalIdGenerator.generateAsString(),             BigDecimal.valueOf(10),             10,         )         val orderItems = listOf(orderItem)         val inventoryService = object : InventoryService {             override fun getInventory(productId: String): Mono<Int> {                 return orderItems.filter { it.productId == productId }.map { it.quantity }.first().toMono()             }         }         val pricingService = object : PricingService {             override fun getProductPrice(productId: String): Mono<BigDecimal> {                 return orderItems.filter { it.productId == productId }                     /*                      * 模拟下单价格、商品定价不一致                      */                     .map { it.price.plus(BigDecimal.valueOf(1)) }.first().toMono()             }         }         aggregateVerifier<Order, OrderState>()             .inject(DefaultCreateOrderSpec(inventoryService, pricingService))             .given()             .`when`(CreateOrder(customerId, orderItems, SHIPPING_ADDRESS, false))             /*              * 期望：价格不一致异常.              */             .expectErrorType(PriceInconsistencyException::class.java).verify()     } }

Saga Unit Test (`SagaVerifier`)

Saga Test

 class CartSagaTest {      @Test     fun onOrderCreated() {         val orderItem = OrderItem(             GlobalIdGenerator.generateAsString(),             GlobalIdGenerator.generateAsString(),             BigDecimal.valueOf(10),             10,         )         sagaVerifier<CartSaga>()             .`when`(                 mockk<OrderCreated> {                     every {                         customerId                     } returns "customerId"                     every {                         items                     } returns listOf(orderItem)                     every {                         fromCart                     } returns true                 },             )             .expectCommandBody<RemoveCartItem> {                 assertThat(it.id, equalTo("customerId"))                 assertThat(it.productIds, hasSize(1))                 assertThat(it.productIds.first(), equalTo(orderItem.productId))             }             .verify()     } }