chore: add tests related to communication with dead processes. (#22)

geth-engine/src/process.rs

@@ -25,6 +25,8 @@ mod echo;
 pub mod grpc;
 pub mod indexing;
 mod messages;
+#[cfg(test)]
+mod panic;
 pub mod reading;
 mod resource;
 #[cfg(test)]
@@ -69,6 +71,8 @@ pub enum Proc {
     Echo,
     #[cfg(test)]
     Sink,
+    #[cfg(test)]
+    Panic,
 }
 
 enum Topology {
@@ -281,6 +285,9 @@ where
 
                         #[cfg(test)]
                         Proc::Sink => spawn(options, client, proc, sink::run),
+
+                        #[cfg(test)]
+                        Proc::Panic => spawn(options, client, proc, panic::run),
                     };
 
                     let proc_id = running_proc.id;

geth-engine/src/process/messages.rs

@@ -10,6 +10,13 @@ pub enum Messages {
     Responses(Responses),
 }
 
+#[cfg(test)]
+impl Messages {
+    pub fn is_fatal_error(&self) -> bool {
+        matches!(self, Messages::Responses(Responses::FatalError))
+    }
+}
+
 impl From<IndexRequests> for Messages {
     fn from(req: IndexRequests) -> Self {
         Messages::Requests(Requests::Index(req))

geth-engine/src/process/panic.rs

@@ -0,0 +1,5 @@
+use super::ProcessEnv;
+
+pub async fn run(_: ProcessEnv) -> eyre::Result<()> {
+    panic!("this process panic on purpose");
+}

geth-engine/src/process/tests/interactions.rs

@@ -11,6 +11,7 @@ fn test_catalog() -> Catalog {
     Catalog::builder()
         .register(Proc::Echo)
         .register(Proc::Sink)
+        .register(Proc::Panic)
         .build()
 }
 
@@ -90,3 +91,31 @@ async fn test_shutdown_reported_properly() -> eyre::Result<()> {
 
     Ok(())
 }
+
+#[tokio::test]
+async fn test_request_returns_when_proc_panicked() -> eyre::Result<()> {
+    let manager = start_process_manager_with_catalog(Options::in_mem(), test_catalog()).await?;
+    let proc_id = manager.wait_for(Proc::Panic).await?;
+
+    let resp = manager
+        .request(proc_id, TestSinkResponses::Stream(42).into())
+        .await?;
+
+    assert!(resp.payload.is_fatal_error());
+
+    Ok(())
+}
+
+#[tokio::test]
+async fn test_stream_returns_when_proc_panicked() -> eyre::Result<()> {
+    let manager = start_process_manager_with_catalog(Options::in_mem(), test_catalog()).await?;
+    let proc_id = manager.wait_for(Proc::Panic).await?;
+
+    let mut resp = manager
+        .request_stream(proc_id, TestSinkResponses::Stream(42).into())
+        .await?;
+
+    assert!(resp.recv().await.is_none());
+
+    Ok(())
+}