remoc 0.18.3

🦑 Remote multiplexed objects, channels, observable collections and RPC making remote interactions seamless. Provides multiple remote channels and RPC over TCP, TLS or any other transport.
Documentation 
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#[cfg(feature = "js")]
use wasm_bindgen_test::wasm_bindgen_test;

use crate::loop_channel;

// Avoid imports here to test if proc macro works without imports.

#[derive(Debug, serde::Serialize, serde::Deserialize)]
pub enum IncreaseError {
    Overflow,
    Call(remoc::rtc::CallError),
}

impl From<remoc::rtc::CallError> for IncreaseError {
    fn from(err: remoc::rtc::CallError) -> Self {
        Self::Call(err)
    }
}

#[remoc::rtc::remote(Server(ReqReceiver))]
pub trait Counter {
    async fn value(&self) -> Result<u32, remoc::rtc::CallError>;
    async fn watch(&mut self) -> Result<remoc::rch::watch::Receiver<u32>, remoc::rtc::CallError>;
    #[no_cancel]
    async fn increase(&mut self, #[serde(default)] by: u32) -> Result<(), IncreaseError>;
}

pub struct CounterObj {
    value: u32,
    watchers: Vec<remoc::rch::watch::Sender<u32>>,
}

impl CounterObj {
    pub fn new() -> Self {
        Self { value: 0, watchers: Vec::new() }
    }

    pub fn handle_req<Codec>(&mut self, req: CounterReq<Codec>)
    where
        Codec: remoc::codec::Codec,
    {
        match req {
            CounterReq::Value { __reply_tx } => {
                let _ = __reply_tx.send(Ok(self.value));
            }
            CounterReq::Watch { __reply_tx } => {
                let (tx, rx) = remoc::rch::watch::channel(self.value);
                self.watchers.push(tx);
                let _ = __reply_tx.send(Ok(rx));
            }
            CounterReq::Increase { __reply_tx, by } => {
                match self.value.checked_add(by) {
                    Some(new_value) => self.value = new_value,
                    None => {
                        let _ = __reply_tx.send(Err(IncreaseError::Overflow));
                        return;
                    }
                }

                for watch in &self.watchers {
                    let _ = watch.send(self.value);
                }

                let _ = __reply_tx.send(Ok(()));
            }
            _ => (),
        }
    }
}

impl Counter for CounterObj {
    async fn value(&self) -> Result<u32, remoc::rtc::CallError> {
        Ok(self.value)
    }

    async fn watch(&mut self) -> Result<remoc::rch::watch::Receiver<u32>, remoc::rtc::CallError> {
        let (tx, rx) = remoc::rch::watch::channel(self.value);
        self.watchers.push(tx);
        Ok(rx)
    }

    async fn increase(&mut self, by: u32) -> Result<(), IncreaseError> {
        match self.value.checked_add(by) {
            Some(new_value) => self.value = new_value,
            None => return Err(IncreaseError::Overflow),
        }

        for watch in &self.watchers {
            let _ = watch.send(self.value);
        }

        Ok(())
    }
}

#[cfg_attr(not(feature = "js"), tokio::test)]
#[cfg_attr(feature = "js", wasm_bindgen_test)]
async fn simple_req() {
    use futures::StreamExt;
    use remoc::rtc::ReqReceiver;

    crate::init();
    let ((mut a_tx, _), (_, mut b_rx)) = loop_channel::<CounterClient>().await;

    println!("Creating counter server");
    let mut counter_obj = CounterObj::new();
    let (mut req_rx, client) = CounterReqReceiver::new(1);

    println!("Sending counter request receiver");
    a_tx.send(client).await.unwrap();

    let client_task = remoc::exec::spawn(async move {
        println!("Receiving counter client");
        let mut client = b_rx.recv().await.unwrap().unwrap();

        println!("Spawning watch...");
        let mut watch_rx = client.watch().await.unwrap();
        remoc::exec::spawn(async move {
            while watch_rx.changed().await.is_ok() {
                println!("Watch value: {}", *watch_rx.borrow_and_update().unwrap());
            }
        });

        println!("value: {}", client.value().await.unwrap());
        assert_eq!(client.value().await.unwrap(), 0);

        println!("add 20");
        client.increase(20).await.unwrap();
        println!("value: {}", client.value().await.unwrap());
        assert_eq!(client.value().await.unwrap(), 20);

        println!("add 45");
        client.increase(45).await.unwrap();
        println!("value: {}", client.value().await.unwrap());
        assert_eq!(client.value().await.unwrap(), 65);
    });

    while let Some(req) = req_rx.next().await {
        let req = req.unwrap();
        counter_obj.handle_req(req);
    }

    client_task.await.unwrap();

    println!("Counter obj value: {}", counter_obj.value);
    assert_eq!(counter_obj.value, 65);
}