Struct MockBus 

pub struct MockBus {
    published: Arc<Mutex<Vec<(String, Vec<u8>)>>>,
    senders: Arc<Mutex<HashMap<String, Vec<Sender<Vec<u8>>>>>>,
    responders: Arc<Mutex<HashMap<String, Vec<Sender<(Vec<u8>, Sender<Vec<u8>>)>>>>>,
}

Combined in-memory message bus for unit tests.

Implements Publisher, Subscriber, Requester, and Responder without a NATS server. Events published via publish() are delivered to any active subscribe() streams on the same subject, and also recorded so tests can assert on what was sent via MockBus::published_as. Commands sent via request() are routed to an active respond() stream on a matching subject, and the handler’s reply is delivered back to the caller.

Service code that takes impl Publisher + impl Subscriber parameters can be fully tested without a running NATS server:

use arminius_lib_message_bus::{
	Event, Publisher, Subscriber, mock::MockBus,
};
use futures::StreamExt;
use serde::{Deserialize, Serialize};

#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
struct OrderCreated {
	order_id: String,
}
impl Event for OrderCreated {
	const SUBJECT: &str = "OrderCreated.v1";
}

async fn handle_order(publisher: &impl Publisher, order_id: &str) {
	publisher
		.publish(OrderCreated { order_id: order_id.to_string() })
		.await
		.unwrap();
}

let bus = MockBus::new();
handle_order(&bus, "order-42").await;
let published = bus.published_as::<OrderCreated>();
assert_eq!(published[0].order_id, "order-42");

Fields

published: Arc<Mutex<Vec<(String, Vec<u8>)>>>

senders: Arc<Mutex<HashMap<String, Vec<Sender<Vec<u8>>>>>>

responders: Arc<Mutex<HashMap<String, Vec<Sender<(Vec<u8>, Sender<Vec<u8>>)>>>>>

Implementations

impl MockBus

pub fn new() -> MockBus

Creates a new empty MockBus.

pub fn published_as<E>(&self) -> Vec<E>

where E: Event,

Returns all events whose published subject matches E::SUBJECT, in order, deserialized. For per-instance events SUBJECT is a wildcard pattern, so every instance’s concrete subject is matched.

Trait Implementations

impl Clone for MockBus

fn clone(&self) -> MockBus

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MockBus

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for MockBus

fn default() -> MockBus

Returns the “default value” for a type.

impl Publisher for MockBus

async fn publish<E>(&self, message: E) -> Result<(), Error>

where E: Event + Clone + 'static,

Publish an event to its subject.

impl Requester for MockBus

async fn request<C>(&self, cmd: C) -> Result<<C as Command>::Reply, Error>

where C: Command,

Send cmd and wait for a typed reply.

impl Responder for MockBus

async fn respond<C>( self, ) -> Result<impl Stream<Item = Result<impl ReceivedCommand<C> + Send + Sync + 'static, Error>> + Send + 'static, Error>

where C: Command + 'static,

Subscribe to commands of type C and return a stream of received commands.

impl Subscriber for MockBus

async fn subscribe<E>( &self, ) -> Result<impl Stream<Item = Result<impl ReceivedEvent<E> + Send + Sync + 'static, Error>> + Send + 'static, Error>

where E: Event + 'static,

Subscribe to events of type E.