Cloud tests that never name a cloud.

@WithCloud(provider = AWS, mode = EMULATOR)
class OrderServiceIT {
  @Test
  void storesTheReceipt(BlobStorage storage) {
    storage.ensureBucket("receipts");
    storage.putObject("receipts", "o-1.json", body, "application/json");
    assertTrue(storage.exists("receipts", "o-1.json"));
  }
}

Given cloud provider is "aws"
And cloud mode is "emulator"
And cloud region is "eu-west-1"
# the steps below mention no AWS service by name

The extension resolves the parameter, ServiceLoader finds the AWS adapter on the classpath, and the adapter starts one LocalStack container per JVM and shares it. Docker has to be running. There is no credential to configure, because there is no account.

Four, deliberately small. A method earns its place only if it is implementable on more than one provider's emulator.

BlobStorage

Ensure and delete a bucket, put an object from bytes or a stream, get, delete, list by prefix, test existence. On AWS this is S3. works

Queue

Ensure and delete a queue, send, receive, receive with a timeout. On AWS this is SQS. works

PubSub

Ensure and delete a topic, ensure a subscription, publish, receive with or without a timeout. On AWS this is SNS delivering to SQS. works

NoSqlTable

Ensure a table with a partition key and optional sort key, put, get, delete, scan, query. On AWS this is DynamoDB. works

Secrets, key management

Named in the service-type enum with no interface behind them. Placeholders, not features. not built

Build

A plain mvn -B verify is green with no skip flags and runs 21 tests: 8 unit, 6 integration against LocalStack, 7 Cucumber scenarios. Formatting, style, dependency convergence and coverage floors are all enforced in that one command. live

Coverage

Line 0.58 and branch 0.30 in the core module; line 0.66 and branch 0.35 in the AWS adapter. The target is 0.80 and 0.70 and neither module meets it. The build enforces the measured numbers as a floor that can only move up, so the gate is honest rather than aspirational. below target

Scope

It tests cloud interactions, not applications. A test asks for a BlobStorage and drives it directly, so you can assert your code writes what you meant. It cannot point a Spring Boot, Quarkus or Micronaut context at the emulator: no endpoint and no credential is reachable from the provider-neutral API, and the only route to one crosses into an internal package and undoes the neutrality the library exists for. Closing that is specified and undecided. not yet

Known defects

The multi-test-class case, which is the case it is aimed at. The emulator container is shared for the whole JVM, the JUnit extension never releases topics or tables, and ensureTable does not check that an existing table's key schema matches the one asked for — so a second test class can silently inherit the first's table and fail later, somewhere else, with a message that names neither. Found by reading the code for this page's own backlog, and recorded rather than left for a user to hit. open

Providers

One. The enum names Azure and GCP; no adapter implements either. Until a second exists, the claim that a test is portable across providers is a design intention, not a demonstrated property. That is the largest open risk in the architecture and it is recorded as such. one only

Modes

Emulator only. A live mode is declared in the enum with no tested path behind it, and it needs a credential story and a guardrail against destructive operations before it means anything. emulator only

Distribution

Not published. No Maven Central release, no private registry. Build it from source. unpublished

Supply chain

An OWASP Dependency-Check audit is wired into CI behind a profile, and is skipped until an NVD API key is configured. It has not yet audited anything, and the page says so rather than implying a clean report. not yet run

The planning documents are in the repository rather than summarised here: a product brief, a PRD with numbered requirements, an architecture spine with its decisions, and a backlog of eight epics covering the gaps above. Read the specs →