Add blob_sidecar event to SSE (#4790)

* Add `blob_sidecar` event to SSE.

* Return 202 if a block is published but failed blob validation when validation level is `Gossip`.

* Move `BlobSidecar` event to `process_gossip_blob` and add test.

* Emit `BlobSidecar` event when blobs are received over rpc.

* Improve test assertions on `SseBlobSidecar`s.

* Add quotes to blob index serialization in `SseBlobSidecar`

Co-authored-by: realbigsean <seananderson33@GMAIL.com>

---------

Co-authored-by: realbigsean <seananderson33@GMAIL.com>

beacon_node/beacon_chain/tests/events.rs

@@ -0,0 +1,99 @@
+use beacon_chain::blob_verification::GossipVerifiedBlob;
+use beacon_chain::test_utils::BeaconChainHarness;
+use bls::Signature;
+use eth2::types::{EventKind, SseBlobSidecar};
+use rand::rngs::StdRng;
+use rand::SeedableRng;
+use std::marker::PhantomData;
+use std::sync::Arc;
+use types::blob_sidecar::FixedBlobSidecarList;
+use types::{BlobSidecar, EthSpec, ForkName, MinimalEthSpec, SignedBlobSidecar};
+
+type E = MinimalEthSpec;
+
+/// Verifies that a blob event is emitted when a gossip verified blob is received via gossip or the publish block API.  
+#[tokio::test]
+async fn blob_sidecar_event_on_process_gossip_blob() {
+    let spec = ForkName::Deneb.make_genesis_spec(E::default_spec());
+    let harness = BeaconChainHarness::builder(E::default())
+        .spec(spec)
+        .deterministic_keypairs(8)
+        .fresh_ephemeral_store()
+        .mock_execution_layer()
+        .build();
+
+    // subscribe to blob sidecar events
+    let event_handler = harness.chain.event_handler.as_ref().unwrap();
+    let mut blob_event_receiver = event_handler.subscribe_blob_sidecar();
+
+    // build and process a gossip verified blob
+    let kzg = harness.chain.kzg.as_ref().unwrap();
+    let mut rng = StdRng::seed_from_u64(0xDEADBEEF0BAD5EEDu64);
+    let signed_sidecar = SignedBlobSidecar {
+        message: BlobSidecar::random_valid(&mut rng, kzg)
+            .map(Arc::new)
+            .unwrap(),
+        signature: Signature::empty(),
+        _phantom: PhantomData,
+    };
+    let gossip_verified_blob = GossipVerifiedBlob::__assumed_valid(signed_sidecar);
+    let expected_sse_blobs = SseBlobSidecar::from_blob_sidecar(gossip_verified_blob.as_blob());
+
+    let _ = harness
+        .chain
+        .process_gossip_blob(gossip_verified_blob)
+        .await
+        .unwrap();
+
+    let sidecar_event = blob_event_receiver.try_recv().unwrap();
+    assert_eq!(sidecar_event, EventKind::BlobSidecar(expected_sse_blobs));
+}
+
+/// Verifies that a blob event is emitted when blobs are received via RPC.  
+#[tokio::test]
+async fn blob_sidecar_event_on_process_rpc_blobs() {
+    let spec = ForkName::Deneb.make_genesis_spec(E::default_spec());
+    let harness = BeaconChainHarness::builder(E::default())
+        .spec(spec)
+        .deterministic_keypairs(8)
+        .fresh_ephemeral_store()
+        .mock_execution_layer()
+        .build();
+
+    // subscribe to blob sidecar events
+    let event_handler = harness.chain.event_handler.as_ref().unwrap();
+    let mut blob_event_receiver = event_handler.subscribe_blob_sidecar();
+
+    // build and process multiple rpc blobs
+    let kzg = harness.chain.kzg.as_ref().unwrap();
+    let mut rng = StdRng::seed_from_u64(0xDEADBEEF0BAD5EEDu64);
+
+    let blob_1 = BlobSidecar::random_valid(&mut rng, kzg)
+        .map(Arc::new)
+        .unwrap();
+    let blob_2 = Arc::new(BlobSidecar {
+        index: 1,
+        ..BlobSidecar::random_valid(&mut rng, kzg).unwrap()
+    });
+    let blobs = FixedBlobSidecarList::from(vec![Some(blob_1.clone()), Some(blob_2.clone())]);
+    let expected_sse_blobs = vec![
+        SseBlobSidecar::from_blob_sidecar(blob_1.as_ref()),
+        SseBlobSidecar::from_blob_sidecar(blob_2.as_ref()),
+    ];
+
+    let _ = harness
+        .chain
+        .process_rpc_blobs(blob_1.slot, blob_1.block_root, blobs)
+        .await
+        .unwrap();
+
+    let mut sse_blobs: Vec<SseBlobSidecar> = vec![];
+    while let Ok(sidecar_event) = blob_event_receiver.try_recv() {
+        if let EventKind::BlobSidecar(sse_blob_sidecar) = sidecar_event {
+            sse_blobs.push(sse_blob_sidecar);
+        } else {
+            panic!("`BlobSidecar` event kind expected.");
+        }
+    }
+    assert_eq!(sse_blobs, expected_sse_blobs);
+}

beacon_node/beacon_chain/tests/main.rs

@@ -2,6 +2,7 @@ mod attestation_production;
 mod attestation_verification;
 mod block_verification;
 mod capella;
+mod events;
 mod merge;
 mod op_verification;
 mod payload_invalidation;