watermelon-testkit

Run tests against isolated, disposable nats-server instances.

Every test gets its own server, bound to random ports on 127.0.0.1 and backed by a private temporary directory, so tests can run in parallel without sharing any state.

use watermelon_testkit::NatsServer;

#[tokio::test]
async fn my_test() {
    let Some(server) = NatsServer::builder().jetstream().start().await else {
        // nats-server isn't installed: skip the test
        return;
    };

    // connect any NATS client to `server.client_url()`
}

The nats-server binary is taken from the NATS_SERVER_BIN environment variable, or looked up in PATH. If it can't be found tests are skipped, unless the CI environment variable is set, in which case they fail.

When a test fails the tail of the server's trace log is printed, and its temporary directory, containing the configuration and the full log, is kept for inspection.