SurrealDB Rust driver and in-memory server: can integration tests connect without any credentials?

Answer

When a SurrealDB instance is started with the mem:// protocol and the --auth flag is omitted, the server accepts WebSocket connections without requiring any authentication. The Rust driver will automatically create an anonymous session if signin is not called. You can immediately call use_ns, use_db, and execute queries such as SELECT 1; and they will succeed.

Confirmed facts (1.x and 2.x)

• In both 1.x and 2.x releases the no‑auth behaviour is identical for the in‑memory mode.
• Calling signin with an empty password is a safe way to verify that the server is indeed running without authentication; the operation should return success.
• If the server was started with --auth or a non‑empty root password, the same signin call will fail with an authentication error, and any query will also fail.

Practical steps for integration tests

1. Start the server with surreal start mem:// (no --auth).
2. In your test, create a client and connect to the WebSocket endpoint, e.g. ws://localhost:8000/rpc.
3. Optionally call client.signin("root", "").await and assert that the result is Ok; this immediately tells you the server is in no‑auth mode.
4. Proceed with client.use_ns("test").await, client.use_db("demo").await, and any query you need.

Detecting misconfiguration early

Include a tiny “sanity” query in the test’s setup phase, for example:

let res = client.query("SELECT 1;").await;
assert!(res.is_ok(), "Server should accept queries without authentication");

If the test fails here, it indicates that the server is running with authentication enabled or a root password is set.

What if the server is started with authentication?

In that case the same SELECT 1; query will return an error such as AuthenticationRequired. The test harness will fail at the sanity check, giving you an early, clear failure message instead of a later obscure error.

Missing diagnostic detail

To be absolutely certain that the test environment is correctly configured, you may want to inspect the server’s startup logs or query the /status endpoint (if available) for the auth flag. If you have access to those logs, could you confirm that the server was launched without --auth?