[Merged by Bors] - #4512 inactivity calculation for Altair

beacon_node/beacon_chain/src/attestation_rewards.rs

@@ -189,6 +189,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             let mut head_reward = 0i64;
             let mut target_reward = 0i64;
             let mut source_reward = 0i64;
+            let mut inactivity_penalty = 0i64;
 
             if eligible {
                 let effective_balance = state.get_effective_balance(*validator_index)?;
@@ -214,6 +215,14 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                         head_reward = 0;
                     } else if flag_index == TIMELY_TARGET_FLAG_INDEX {
                         target_reward = *penalty;
+
+                        let penalty_numerator = effective_balance
+                            .safe_mul(state.get_inactivity_score(*validator_index)?)?;
+                        let penalty_denominator = spec
+                            .inactivity_score_bias
+                            .safe_mul(spec.inactivity_penalty_quotient_for_state(&state))?;
+                        inactivity_penalty =
+                            penalty_numerator.safe_div(penalty_denominator)? as i64;
                     } else if flag_index == TIMELY_SOURCE_FLAG_INDEX {
                         source_reward = *penalty;
                     }
@@ -225,8 +234,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                 target: target_reward,
                 source: source_reward,
                 inclusion_delay: None,
-                // TODO: altair calculation logic needs to be updated to include inactivity penalty
-                inactivity: 0,
+                inactivity: inactivity_penalty * -1,
             });
         }
 
@@ -249,7 +257,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                             target: 0,
                             source: 0,
                             inclusion_delay: None,
-                            // TODO: altair calculation logic needs to be updated to include inactivity penalty
                             inactivity: 0,
                         });
                     match *flag_index {

beacon_node/beacon_chain/tests/rewards.rs

@@ -14,7 +14,7 @@ use eth2::lighthouse::StandardAttestationRewards;
 use eth2::types::ValidatorId;
 use lazy_static::lazy_static;
 use types::beacon_state::Error as BeaconStateError;
-use types::{BeaconState, ChainSpec};
+use types::{BeaconState, ChainSpec, ForkName};
 
 pub const VALIDATOR_COUNT: usize = 64;
 
@@ -219,6 +219,75 @@ async fn test_verify_attestation_rewards_base_inactivity_leak() {
     assert_eq!(expected_balances, balances);
 }
 
+#[tokio::test]
+async fn test_verify_attestation_rewards_altair_inactivity_leak() {
+    let spec = ForkName::Altair.make_genesis_spec(E::default_spec());
+    let harness = get_harness(spec.clone());
+
+    let half = VALIDATOR_COUNT / 2;
+    let half_validators: Vec<usize> = (0..half).collect();
+    // target epoch is the epoch where the chain enters inactivity leak
+    let target_epoch = &spec.min_epochs_to_inactivity_penalty + 2;
+
+    // advance until beginning of epoch N + 1 and get balances
+    harness
+        .extend_chain(
+            (E::slots_per_epoch() * (target_epoch + 1)) as usize,
+            BlockStrategy::OnCanonicalHead,
+            AttestationStrategy::SomeValidators(half_validators.clone()),
+        )
+        .await;
+    let initial_balances: Vec<u64> = harness.get_current_state().balances().clone().into();
+
+    // extend slots to beginning of epoch N + 2
+    harness.advance_slot();
+    harness
+        .extend_chain(
+            E::slots_per_epoch() as usize,
+            BlockStrategy::OnCanonicalHead,
+            AttestationStrategy::SomeValidators(half_validators),
+        )
+        .await;
+    let _slot = harness.get_current_slot();
+
+    // compute reward deltas for all validators in epoch N
+    let StandardAttestationRewards {
+        ideal_rewards,
+        total_rewards,
+    } = harness
+        .chain
+        .compute_attestation_rewards(Epoch::new(target_epoch), vec![])
+        .unwrap();
+
+    // assert inactivity penalty for both ideal rewards and individual validators
+    assert!(ideal_rewards.iter().all(|reward| reward.inactivity == 0));
+    assert!(total_rewards[..half]
+        .iter()
+        .all(|reward| reward.inactivity == 0));
+    assert!(total_rewards[half..]
+        .iter()
+        .all(|reward| reward.inactivity < 0));
+
+    // apply attestation rewards to initial balances
+    let expected_balances = apply_attestation_rewards(&initial_balances, total_rewards);
+
+    for initial_balance in &initial_balances {
+        println!("initial {initial_balance}");
+    }
+
+    for expected_balance in &expected_balances {
+        println!("expected {expected_balance}");
+    }
+    // verify expected balances against actual balances
+    let balances: Vec<u64> = harness.get_current_state().balances().clone().into();
+
+    for balance in &balances {
+        println!("actual {balance}");
+    }
+    // Failing test statement
+    assert_eq!(expected_balances, balances);
+}
+
 #[tokio::test]
 async fn test_verify_attestation_rewards_base_subset_only() {
     let harness = get_harness(E::default_spec());