notify router: log each delivered forge event and each sink outcome

swarm-notify-router/src/log.rs

@@ -80,6 +80,43 @@ impl Cause {
     }
 }
 
+/// Log one routed delivery: at info when `flows` flows produced a todo or a
+/// review request, at debug when none did, so deliveries nothing wants do not
+/// flood the log. It names the sender and never the body.
+pub fn delivery(
+    event_type: &str,
+    delivery: &crate::event::Delivery,
+    delivery_id: Option<&str>,
+    flows: usize,
+) {
+    let (repo, number, sender, action) = (
+        &delivery.repo,
+        delivery.number,
+        &delivery.sender,
+        &delivery.action,
+    );
+    let delivery_id = delivery_id.unwrap_or("none");
+    if flows == 0 {
+        tracing::debug!(event_type, %action, %repo, number, %sender, delivery_id, flows, "notify router: forge event matched no flow");
+    } else {
+        tracing::info!(event_type, %action, %repo, number, %sender, delivery_id, flows, "notify router: forge event routed");
+    }
+}
+
+/// Log what one sink of `flow` did for `target` on the issue or PR `cause` names: info when it went through,
+/// warn with the error when it did not.
+pub fn sink(cause: &Cause, flow: &str, kind: Kind, target: &str, result: &Result<String, String>) {
+    let (repo, number) = (&cause.repo, cause.number);
+    match result {
+        Ok(outcome) => {
+            tracing::info!(%flow, %repo, number, ?kind, %target, %outcome, "notify router: sink ran");
+        }
+        Err(error) => {
+            tracing::warn!(%flow, %repo, number, ?kind, %target, %error, "notify router: sink failed");
+        }
+    }
+}
+
 /// Append `row`; a failure, or an append that takes longer than
 /// `APPEND_WITHIN`, is logged and dropped. It is awaited in place, so rows
 /// keep the order of the deliveries.