Update attestation rewards API for Electra (#6819)

Closes:

- https://github.com/sigp/lighthouse/issues/6818


  Use `MAX_EFFECTIVE_BALANCE_ELECTRA` (2048) for attestation reward calculations involving Electra.

Add a new `InteropGenesisBuilder` that tries to provide a more flexible way to build genesis states. Unfortunately due to lifetime jank, it is quite unergonomic at present. We may want to refactor this builder in future to make it easier to use.

beacon_node/http_api/tests/fork_tests.rs

@@ -5,7 +5,7 @@ use beacon_chain::{
 };
 use eth2::types::{IndexedErrorMessage, StateId, SyncSubcommittee};
 use execution_layer::test_utils::generate_genesis_header;
-use genesis::{bls_withdrawal_credentials, interop_genesis_state_with_withdrawal_credentials};
+use genesis::{bls_withdrawal_credentials, InteropGenesisBuilder};
 use http_api::test_utils::*;
 use std::collections::HashSet;
 use types::{
@@ -346,35 +346,46 @@ fn assert_server_indexed_error(error: eth2::Error, status_code: u16, indices: Ve
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn bls_to_execution_changes_update_all_around_capella_fork() {
-    let validator_count = 128;
+    const VALIDATOR_COUNT: usize = 128;
     let fork_epoch = Epoch::new(2);
     let spec = capella_spec(fork_epoch);
     let max_bls_to_execution_changes = E::max_bls_to_execution_changes();
 
     // Use a genesis state with entirely BLS withdrawal credentials.
-    // Offset keypairs by `validator_count` to create keys distinct from the signing keys.
-    let validator_keypairs = generate_deterministic_keypairs(validator_count);
-    let withdrawal_keypairs = (0..validator_count)
-        .map(|i| Some(generate_deterministic_keypair(i + validator_count)))
-        .collect::<Vec<_>>();
-    let withdrawal_credentials = withdrawal_keypairs
-        .iter()
-        .map(|keypair| bls_withdrawal_credentials(&keypair.as_ref().unwrap().pk, &spec))
+    // Offset keypairs by `VALIDATOR_COUNT` to create keys distinct from the signing keys.
+    let validator_keypairs = generate_deterministic_keypairs(VALIDATOR_COUNT);
+    let withdrawal_keypairs = (0..VALIDATOR_COUNT)
+        .map(|i| Some(generate_deterministic_keypair(i + VALIDATOR_COUNT)))
         .collect::<Vec<_>>();
+
+    fn withdrawal_credentials_fn<'a>(
+        index: usize,
+        _: &'a types::PublicKey,
+        spec: &'a ChainSpec,
+    ) -> Hash256 {
+        // It is a bit inefficient to regenerate the whole keypair here, but this is a workaround.
+        // `InteropGenesisBuilder` requires the `withdrawal_credentials_fn` to have
+        // a `'static` lifetime.
+        let keypair = generate_deterministic_keypair(index + VALIDATOR_COUNT);
+        bls_withdrawal_credentials(&keypair.pk, spec)
+    }
+
     let header = generate_genesis_header(&spec, true);
-    let genesis_state = interop_genesis_state_with_withdrawal_credentials(
-        &validator_keypairs,
-        &withdrawal_credentials,
-        HARNESS_GENESIS_TIME,
-        Hash256::from_slice(DEFAULT_ETH1_BLOCK_HASH),
-        header,
-        &spec,
-    )
-    .unwrap();
+
+    let genesis_state = InteropGenesisBuilder::new()
+        .set_opt_execution_payload_header(header)
+        .set_withdrawal_credentials_fn(Box::new(withdrawal_credentials_fn))
+        .build_genesis_state(
+            &validator_keypairs,
+            HARNESS_GENESIS_TIME,
+            Hash256::from_slice(DEFAULT_ETH1_BLOCK_HASH),
+            &spec,
+        )
+        .unwrap();
 
     let tester = InteractiveTester::<E>::new_with_initializer_and_mutator(
         Some(spec.clone()),
-        validator_count,
+        VALIDATOR_COUNT,
         Some(Box::new(|harness_builder| {
             harness_builder
                 .keypairs(validator_keypairs)
@@ -421,7 +432,7 @@ async fn bls_to_execution_changes_update_all_around_capella_fork() {
             let pubkey = &harness.get_withdrawal_keypair(validator_index).pk;
             // And the wrong secret key.
             let secret_key = &harness
-                .get_withdrawal_keypair((validator_index + 1) % validator_count as u64)
+                .get_withdrawal_keypair((validator_index + 1) % VALIDATOR_COUNT as u64)
                 .sk;
             harness.make_bls_to_execution_change_with_keys(
                 validator_index,
@@ -433,7 +444,7 @@ async fn bls_to_execution_changes_update_all_around_capella_fork() {
         .collect::<Vec<_>>();
 
     // Submit some changes before Capella. Just enough to fill two blocks.
-    let num_pre_capella = validator_count / 4;
+    let num_pre_capella = VALIDATOR_COUNT / 4;
     let blocks_filled_pre_capella = 2;
     assert_eq!(
         num_pre_capella,
@@ -488,7 +499,7 @@ async fn bls_to_execution_changes_update_all_around_capella_fork() {
     );
 
     // Add Capella blocks which should be full of BLS to execution changes.
-    for i in 0..validator_count / max_bls_to_execution_changes {
+    for i in 0..VALIDATOR_COUNT / max_bls_to_execution_changes {
         let head_block_root = harness.extend_slots(1).await;
         let head_block = harness
             .chain
@@ -534,7 +545,7 @@ async fn bls_to_execution_changes_update_all_around_capella_fork() {
             assert_server_indexed_error(
                 error,
                 400,
-                (validator_count..3 * validator_count).collect(),
+                (VALIDATOR_COUNT..3 * VALIDATOR_COUNT).collect(),
             );
         }
     }