Add first changes to syncing logic

- Adds testing framework
- Breaks out new `NetworkContext` object

beacon_node/network/tests/tests.rs

@@ -0,0 +1,184 @@
+use beacon_chain::test_utils::TestingBeaconChainBuilder;
+use crossbeam_channel::{unbounded, Receiver, Sender};
+use libp2p::rpc::{HelloMessage, RPCMethod, RPCRequest, RPCResponse};
+use libp2p::{PeerId, RPCEvent};
+use network::beacon_chain::BeaconChain as NetworkBeaconChain;
+use network::message_handler::{HandlerMessage, MessageHandler};
+use network::service::{NetworkMessage, OutgoingMessage};
+use sloggers::terminal::{Destination, TerminalLoggerBuilder};
+use sloggers::types::Severity;
+use sloggers::Build;
+use std::sync::Arc;
+use test_harness::BeaconChainHarness;
+use tokio::runtime::TaskExecutor;
+use types::{test_utils::TestingBeaconStateBuilder, *};
+
+pub struct SyncNode {
+    pub id: usize,
+    sender: Sender<HandlerMessage>,
+    receiver: Receiver<NetworkMessage>,
+}
+
+impl SyncNode {
+    pub fn new(
+        id: usize,
+        executor: &TaskExecutor,
+        chain: Arc<NetworkBeaconChain>,
+        logger: slog::Logger,
+    ) -> Self {
+        let (network_sender, network_receiver) = unbounded();
+        let message_handler_sender =
+            MessageHandler::spawn(chain, network_sender, executor, logger).unwrap();
+
+        Self {
+            id,
+            sender: message_handler_sender,
+            receiver: network_receiver,
+        }
+    }
+
+    fn send(&self, message: HandlerMessage) {
+        self.sender.send(message).unwrap();
+    }
+
+    fn recv(&self) -> NetworkMessage {
+        self.receiver.recv().unwrap()
+    }
+
+    fn recv_rpc_response(&self) -> RPCResponse {
+        let network_message = self.recv();
+        match network_message {
+            NetworkMessage::Send(
+                _peer_id,
+                OutgoingMessage::RPC(RPCEvent::Response {
+                    id: _,
+                    method_id: _,
+                    result,
+                }),
+            ) => result,
+            _ => panic!("get_rpc_response failed! got {:?}", network_message),
+        }
+    }
+
+    fn recv_rpc_request(&self) -> RPCRequest {
+        let network_message = self.recv();
+        match network_message {
+            NetworkMessage::Send(
+                _peer_id,
+                OutgoingMessage::RPC(RPCEvent::Request {
+                    id: _,
+                    method_id: _,
+                    body,
+                }),
+            ) => body,
+            _ => panic!("get_rpc_request failed! got {:?}", network_message),
+        }
+    }
+}
+
+fn get_logger() -> slog::Logger {
+    let mut builder = TerminalLoggerBuilder::new();
+    builder.level(Severity::Debug);
+    builder.destination(Destination::Stderr);
+    builder.build().unwrap()
+}
+
+pub struct SyncMaster {
+    harness: BeaconChainHarness,
+    peer_id: PeerId,
+    response_ids: Vec<u64>,
+}
+
+impl SyncMaster {
+    fn from_beacon_state_builder(
+        state_builder: TestingBeaconStateBuilder,
+        node_count: usize,
+        spec: &ChainSpec,
+    ) -> Self {
+        let harness = BeaconChainHarness::from_beacon_state_builder(state_builder, spec.clone());
+        let peer_id = PeerId::random();
+        let response_ids = vec![0; node_count];
+
+        Self {
+            harness,
+            peer_id,
+            response_ids,
+        }
+    }
+
+    pub fn response_id(&mut self, node: &SyncNode) -> u64 {
+        let id = self.response_ids[node.id];
+        self.response_ids[node.id] += 1;
+        id
+    }
+
+    pub fn do_hello_with(&mut self, node: &SyncNode) {
+        let message = HandlerMessage::PeerDialed(self.peer_id.clone());
+        node.send(message);
+
+        let request = node.recv_rpc_request();
+
+        match request {
+            RPCRequest::Hello(_hello) => {
+                let hello = self.harness.beacon_chain.hello_message();
+                let response = self.rpc_response(node, RPCResponse::Hello(hello));
+                node.send(response);
+            }
+            _ => panic!("Got message other than hello from node."),
+        }
+    }
+
+    fn rpc_response(&mut self, node: &SyncNode, rpc_response: RPCResponse) -> HandlerMessage {
+        HandlerMessage::RPC(
+            self.peer_id.clone(),
+            RPCEvent::Response {
+                id: self.response_id(node),
+                method_id: RPCMethod::Hello.into(),
+                result: rpc_response,
+            },
+        )
+    }
+}
+
+fn test_setup(
+    state_builder: TestingBeaconStateBuilder,
+    node_count: usize,
+    spec: &ChainSpec,
+    logger: slog::Logger,
+) -> (tokio::runtime::Runtime, SyncMaster, Vec<SyncNode>) {
+    let runtime = tokio::runtime::Runtime::new().unwrap();
+
+    let mut nodes = Vec::with_capacity(node_count);
+    for id in 0..node_count {
+        let local_chain = TestingBeaconChainBuilder::from(state_builder.clone()).build(&spec);
+        let node = SyncNode::new(
+            id,
+            &runtime.executor(),
+            Arc::new(local_chain),
+            logger.clone(),
+        );
+
+        nodes.push(node);
+    }
+
+    let master = SyncMaster::from_beacon_state_builder(state_builder, node_count, &spec);
+
+    (runtime, master, nodes)
+}
+
+#[test]
+fn first_test() {
+    let logger = get_logger();
+    let spec = ChainSpec::few_validators();
+    let validator_count = 8;
+    let node_count = 1;
+
+    let state_builder =
+        TestingBeaconStateBuilder::from_default_keypairs_file_if_exists(validator_count, &spec);
+
+    let (runtime, mut master, nodes) = test_setup(state_builder, node_count, &spec, logger.clone());
+
+    master.do_hello_with(&nodes[0]);
+
+    runtime.shutdown_now();
+}