单元测试指南

配置测试依赖

dependencies {
    testImplementation("me.ahoo.cocache:cocache-test:5.0.0")
}

cocache-test 会带入 JUnit 5、fluent-assert 和 cocache-core。每个规格都是抽象 JUnit 类：继承它并实现工厂方法即可。

flowchart LR
    Impl["Your implementation"] --> Pick{"What is it?"}
    Pick -->|"L2 store"| CSC["ClientSideCacheSpec"]
    Pick -->|"L1 store"| DC["DistributedCacheSpec"]
    Pick -->|"Cache<K, V>"| C["CacheSpec"]
    Pick -->|"L1 + channel end-to-end"| CO["DefaultCoherentCacheSpec<br>MultipleInstanceSyncSpec"]
    Pick -->|"event channel"| EB["CacheEvictedEventBusSpec"]

    style Impl fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style Pick fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style CSC fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style DC fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style C fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style CO fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style EB fill:#2d333b,stroke:#6d5dfc,color:#e6edf3

测试存储（L2 / L1）

internal class CaffeineClientSideCacheTest : ClientSideCacheSpec<String>() {
    override fun createCacheStore(): ClientSideCache<String> = CaffeineClientSideCache.build()
    override fun createCacheEntry(): Pair<String, String> =
        UUID.randomUUID().toString() to UUID.randomUUID().toString()
}

对于从服务端过期时间重建 ttlAt 的存储（Redis），覆写 open 的 setWithTtlAt / setMissingWithTtlAt，允许 ±1 秒漂移：

@Test
override fun setWithTtlAt() {
    val (key, value) = createCacheEntry()
    val cacheValue = CacheValue.of(value, TtlAt.at(10))
    cacheStore.setCache(key, cacheValue)
    requireNotNull(cacheStore.getCache(key)).ttlAt.assert().isCloseTo(cacheValue.ttlAt, Offset.offset(1))
}

测试缓存

class ProxyCacheTest : CacheSpec<String, String>() {
    override fun createCache(): Cache<String, String> = createProxyCache<MockCache>()
    override fun createCacheEntry() = UUID.randomUUID().toString() to UUID.randomUUID().toString()
}

测试一致性

DefaultCoherentCacheSpec 用你提供的组件构建 DefaultCoherentCache。它的默认 CacheSource 由受保护的 loader 驱动，并用 sourceCalls 统计调用次数。

internal class RedisDefaultCoherentCacheTest : DefaultCoherentCacheSpec<String, String>() {
    private lateinit var redis: RedisTestSupport

    @BeforeEach
    override fun setup() { redis = RedisTestSupport(); super.setup() }

    @AfterEach
    override fun tearDown() { super.tearDown(); redis.close() }

    override fun createKeyConverter(): KeyConverter<String> = ToStringKeyConverter("coherent-test:")
    override fun createClientSideCache(): ClientSideCache<String> = MapClientSideCache()
    override fun createDistributedCache(): DistributedCache<String> =
        RedisDistributedCache(redis.redisTemplate, StringToStringCodecExecutor(redis.redisTemplate))
    override fun createCacheEvictedEventBus(): CacheEvictedEventBus = redis.newEventBus()
    override fun createCacheName(): String = "RedisDefaultCoherentCacheTest-" + UUID.randomUUID()
    override fun createCacheEntry() = UUID.randomUUID().toString() to UUID.randomUUID().toString()
}

覆写 JUnit 生命周期方法时必须重复标注 @BeforeEach / @AfterEach，否则 JUnit 不会执行该覆写方法。

异步通道会异步投递（重新）订阅时的 onReset，迟到的重置会在测试中途清空 L2。使用 Spring Data Redis 时，在测试中给 RedisMessageListenerContainer 配置 SyncTaskExecutor，这样 register() 返回时重置已经执行完。

sequenceDiagram
autonumber
    participant Spec as DefaultCoherentCacheSpec
    participant F as DefaultCoherentCacheFactory
    participant Bus as CacheEvictedEventBus
    participant C as DefaultCoherentCache

    Spec->>F: create(configuration)
    F->>Bus: register(cache)
    Bus-->>C: onReset() (sync executor: before register returns)
    Spec->>C: run test
    Spec->>C: close() in @AfterEach

测试事件通道

class LocalCacheEvictedEventBusTest : CacheEvictedEventBusSpec() {
    override fun createCacheEvictedEventBus(): CacheEvictedEventBus = LocalCacheEvictedEventBus()
}

Fluent Assert 与 mockk

import me.ahoo.test.asserts.assert

cache[key].assert().isEqualTo(value)
requireNotNull(cache.getCache(key)).isMissing.assert().isTrue()
runCatching { cache[key] }.exceptionOrNull().assert().isSameAs(failure)

• 禁止使用 AssertJ assertThat()；Offset.offset(n) 作为参数可以使用。
• assert() 接受可空接收者。优先用 requireNotNull(...)，而不是 !!。
• 每个模块的测试 classpath 都有 mockk，例如 mockk<DistributedCache<String>>(relaxUnitFun = true)。

测试命令

./gradlew :cocache-core:test
./gradlew :cocache-core:test --tests "me.ahoo.cache.consistency.DefaultCoherentCacheTest"
./gradlew :cocache-spring-redis:test   # 需要 localhost:6379 的 Redis

相关页面

• 测试概览
• 集成测试