Test harness¶

mongoose-test-support wraps a booted MongooseServer as an AutoCloseable, with a builder for the common feed/sink/processor wiring and a small suite of await helpers. Replaces ~30 lines of boot/teardown ceremony per integration test with ~10.

<dependency>
    <groupId>com.telamin</groupId>
    <artifactId>mongoose-test-support</artifactId>
    <version>1.0.35</version>
    <scope>test</scope>
</dependency>

Quick start¶

import com.telamin.mongoose.plugin.testsupport.MongooseTestHarness;
import com.telamin.mongoose.connector.memory.InMemoryEventSource;
import com.telamin.mongoose.connector.memory.InMemoryMessageSink;

@Test
void echo() {
    InMemoryEventSource<String> feed = new InMemoryEventSource<>();
    InMemoryMessageSink captured = new InMemoryMessageSink();

    try (MongooseTestHarness h = MongooseTestHarness.builder()
            .feed("in", feed, "feed-agent")
            .sink("out", captured)
            .processor("processor-agent", "echo", new EchoHandler())
            .start()) {

        feed.offer("alpha");
        feed.offer("beta");

        h.awaitCondition(() -> captured.getMessages().size() >= 2);

        assertEquals(List.of("echo:alpha", "echo:beta"), captured.getMessages());
    }
}

What it replaces¶

A typical pre-harness integration test:

// build sources/sinks/processors
FileEventSource source = new FileEventSource();
source.setFilename(input.toString());
source.setReadStrategy(ReadStrategy.EARLIEST);

FileMessageSink sink = new FileMessageSink();
sink.setFilename(output.toString());

var feed = EventFeedConfig.builder()
        .instance(source).name("file-feed").broadcast(true)
        .agent("file-source-agent", new SleepingMillisIdleStrategy(1))
        .build();

var sinkCfg = EventSinkConfig.builder()
        .instance(sink).name("file-sink").build();

var processor = EventProcessorConfig.builder()
        .customHandler(new ForwardingHandler())
        .name("forwarder").build();

var app = MongooseServerConfig.builder()
        .addProcessor("processor-agent", processor)
        .addEventFeed(feed)
        .addEventSink(sinkCfg)
        .build();

MongooseServer server = MongooseServer.bootServer(app);
try {
    long deadline = System.currentTimeMillis() + 3_000;
    while (System.currentTimeMillis() < deadline) {
        if (Files.exists(output)
                && Files.readAllLines(output).size() >= 3) break;
        Thread.sleep(20);
    }
    assertEquals(expected, Files.readAllLines(output));
} finally {
    server.stop();
}

The same test with the harness:

FileEventSource source = new FileEventSource();
source.setFilename(input.toString());
source.setReadStrategy(ReadStrategy.EARLIEST);

FileMessageSink sink = new FileMessageSink();
sink.setFilename(output.toString());

try (MongooseTestHarness h = MongooseTestHarness.builder()
        .feed("file-feed", source, "file-source-agent")
        .sink("file-sink", sink)
        .processor("processor-agent", "forwarder", new ForwardingHandler())
        .start()) {

    h.awaitFileLines(output, 3);
    assertEquals(expected, Files.readAllLines(output));
}

API surface¶

Builder¶

Method	Purpose
`feed(name, source, agentName)`	Add an event feed
`feed(name, source, agentName, idleStrategy)`	Same with explicit idle strategy
`sink(name, sink)`	Add a message sink
`service(name, instance)`	Register service under the concrete class
`service(name, instance, serviceClass)`	Register under an interface — see serviceClass
`processor(agentName, handlerName, ObjectEventHandlerNode)`	Typed processor
`processor(agentName, handlerName, Consumer<Object>)`	Function-style processor
`defaultIdleStrategy(idleStrategy)`	Override the default (`SleepingMillisIdleStrategy(1)`)
`customise(fn)`	Escape hatch onto the raw `MongooseServerConfig.Builder`
`start()`	Build, boot, return harness

Harness¶

Method	Purpose
`awaitCondition(BooleanSupplier)`	Poll until true; default 3 s timeout
`awaitCondition(BooleanSupplier, Duration)`	Poll until true or `AssertionError`
`awaitFileLines(Path, int)`	Poll until file has N lines
`awaitFileLines(Path, int, Duration)`	Same with explicit timeout
`readLines(Path)`	Read file as UTF-8 lines (unchecked I/O)
`server()`	The underlying `MongooseServer`
`close()`	Stop server; idempotent
`MongooseTestHarness.wrap(server)`	Adopt an externally-booted server

Conventions¶

Always try-with-resources — start() returns AutoCloseable; don't manage server.stop() manually.
Use awaitCondition, not Thread.sleep — sleeps are flaky on CI; condition polls succeed as soon as the predicate holds.
One harness per test — fresh server each time. Shared servers create ordering coupling.
@TempDir for any file paths — auto-cleanup and isolation.

When to drop down¶

If you need something the builder doesn't expose:

try (MongooseTestHarness h = MongooseTestHarness.builder()
        .feed("in", feed, "feed-agent")
        .customise(b -> b
            .addThread(new ThreadConfig("custom-thread", true))
            .eventInvokeStrategy(CallBackType.ON_TRIGGER, MyStrategy::new))
        .start()) {
    // ...
}

customise(...) hands you the underlying MongooseServerConfig.Builder — every config method is available.

Source¶

mongoose-plugins/test-support/mongoose-test-support