Testing Overview

CoCache verifies every implementation against shared specifications in cocache-test (a Technology Compatibility Kit). A new store, cache, or event channel passes the same contract tests as the built-in ones.

Spec Hierarchy

graph TB
    subgraph tck ["cocache-test (TCK)"]
        direction TB
        StoreSpec["CacheStoreSpec<br>store contract"]
        CSCSpec["ClientSideCacheSpec<br>+ clear / size"]
        DCSpec["DistributedCacheSpec"]
        CacheSpec["CacheSpec<br>Cache semantics"]
        CoherentSpec["DefaultCoherentCacheSpec<br>coherence invariants"]
        MISpec["MultipleInstanceSyncSpec<br>cross-instance sync"]
        EBSpec["CacheEvictedEventBusSpec<br>channel contract"]
    end

    subgraph core ["cocache-core tests"]
        Caffeine["CaffeineClientSideCacheTest"]
        Map["MapClientSideCacheTest"]
        InMem["InMemoryDistributedCacheTest"]
        Coherent["DefaultCoherentCacheTest"]
        Join["SimpleJoinCacheTest"]
        Local["LocalCacheEvictedEventBusTest"]
    end

    subgraph redis ["cocache-spring-redis tests"]
        RedisDC["RedisDistributedCachingTest"]
        RedisCoherent["RedisDefaultCoherentCacheTest"]
        RedisSync["RedisMultipleInstanceSyncTest"]
        RedisBus["RedisCacheEvictedEventBusTest"]
    end

    StoreSpec --> CSCSpec
    StoreSpec --> DCSpec
    CacheSpec --> CoherentSpec
    CSCSpec --> Caffeine
    CSCSpec --> Map
    DCSpec --> InMem
    DCSpec --> RedisDC
    CoherentSpec --> Coherent
    CoherentSpec --> RedisCoherent
    CacheSpec --> Join
    MISpec --> RedisSync
    EBSpec --> Local
    EBSpec --> RedisBus

    style StoreSpec fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style CSCSpec fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style DCSpec fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style CacheSpec fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style CoherentSpec fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style MISpec fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style EBSpec fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style Caffeine fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style Map fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style InMem fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style Coherent fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style Join fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style Local fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style RedisDC fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style RedisCoherent fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style RedisSync fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style RedisBus fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style tck fill:#161b22,stroke:#8b949e,color:#e6edf3
    style core fill:#161b22,stroke:#8b949e,color:#e6edf3
    style redis fill:#161b22,stroke:#8b949e,color:#e6edf3

Specs

Spec	Verifies	Source
CacheStoreSpec	absent key → null; forever / ttlAt round trip; expired write evicts; negative-cache round trip; evict	CacheStoreSpec.kt
ClientSideCacheSpec	+ clear(), size	ClientSideCacheSpec.kt
DistributedCacheSpec	store contract for L1	DistributedCacheSpec.kt
CacheSpec	get/set/getTtlAt/evict, negative cache via setCache	CacheSpec.kt
DefaultCoherentCacheSpec	read-through, missingTtl, L1 → L2 fill, event handling, onReset, single load under concurrency, original exception propagation, recursive-load fail-fast, and every in-flight invalidation race	DefaultCoherentCacheSpec.kt
MultipleInstanceSyncSpec	two instances sharing L1 + channel converge after set / evict	MultipleInstanceSyncSpec.kt
CacheEvictedEventBusSpec	register triggers onReset; publish routing by cache name; unregister	CacheEvictedEventBusSpec.kt

Race-Condition Tests

Every coherence defect fixed in 5.0 has a reproducing test in DefaultCoherentCacheSpec:

Test	Reproduces
local evict during in-flight load discards stale write-back	4.x: a local evict did not stop a concurrent load from writing an old value back
local set during in-flight load keeps the newer value	A concurrent load cannot overwrite an explicit set
remote eviction during in-flight load discards ...	A remote event that arrives during a load wins
reset during in-flight load discards stale write-back	A channel reset invalidates in-flight loads
remote eviction during distributed read discards client side fill	The L1 → L2 fill is guarded too
CodecExecutorSpec.absentKeyIsMiss (Redis)	4.x: a key deleted mid-read was decoded as a negative cache

sequenceDiagram
autonumber
    participant Test
    participant Loader as Loader thread
    participant Cache as DefaultCoherentCache
    participant Src as CacheSource

    Test->>Loader: start getCache(key)
    Loader->>Cache: getCache(key)
    Cache->>Src: load (blocks on latch)
    Test->>Cache: evict(key) / onEvicted / onReset
    Test->>Src: release latch
    Src-->>Cache: stale value
    Cache-->>Loader: value returned, NOT cached
    Test->>Test: assert L1 and L2 are empty

Conventions:

• Orchestrate with latches; never use sleeps to create an interleaving.
• Wait on a finished latch so a dead background thread fails the test instead of passing vacuously.
• Assert eventual cross-instance effects by polling with a timeout.

Test Tools

Tool	Usage
JUnit 5	Framework; @ParameterizedTest for concurrency levels
mockk	Mocking
fluent-assert	import me.ahoo.test.asserts.assert, then .assert() (never AssertJ assertThat)

Related Pages

• Unit Testing
• Integration Testing
• Performance Patterns