Testing, operations, and ecosystem

1.11.0 test structure

AbstractReactiveMongoTest lazily starts a MongoDBServer Testcontainer and registers spring.data.mongodb.uri dynamically. AbstractReactiveMongoCoroutineTest adds a test scope with Dispatchers.IO and a CoroutineName.

ReactiveMongoOperationsCoroutinesTest uses a real Spring Boot context and MongoDB to verify:

• insert and save;
• Flow, optional, and required reads;
• count and exists;
• update-first, update-multi, and upsert;
• remove, find-and-modify, and find-and-remove;
• distinct and aggregation;
• collection existence, creation, and removal.

The three query-DSL test classes compare BSON structures without a server. Run the fast DSL checks first, then serialize the Docker-backed suite with other Testcontainers work.

Isolate test data

The integration suite uses the dedicated test_users collection. Give each test a unique business key such as email and remove only documents created by that test. Assertions against a shared collection’s absolute count are sensitive to execution order and parallelism.

./gradlew :bluetape4k-spring-boot-mongodb:test \
    --no-build-cache --no-configuration-cache

Operational signals

The module adds no metrics, so use Spring Boot and MongoDB driver observation.

Signal	Possible problem
Server-selection time	Topology change, DNS/network issues, no primary
Pool wait and in-use connections	Pool exhaustion, long query, slow Flow consumer
Command latency and error code	Missing index, timeout, duplicate key, write concern
Cancellation and request latency	Client disconnect, deadline, excessive result size
Active subscriptions during shutdown	Tailable cursor or coroutine scope not closed

Choose the MongoDB layer

Need	Starting point
Spring Data mapping, ReactiveMongoOperations, and coroutines	This module
Spring Data repository interface	Spring Data reactive/coroutine repository
Direct MongoDB Kotlin driver, codec, and collection control	bluetape4k-mongodb
Spring Boot client, properties, and health configuration	Spring Boot MongoDB auto-configuration

Both bluetape4k modules can be present, but avoid casually mixing Spring Data mapping and native codec mapping in one repository. Assign document wire format and transaction/session ownership to one clear layer.

Source and tests

• AbstractReactiveMongoTest.kt
• AbstractReactiveMongoCoroutineTest.kt
• MongoTestApplication.kt
• ReactiveMongoOperationsCoroutinesTest.kt
• User.kt

Next step

After choosing the layer, return to Auto-configuration and ownership boundaries and pin the beans and settings owned by the application.