Add test for sync committee block rewards

tests/core/pyspec/eth2spec/test/lightclient_patch/block_processing/test_process_sync_committee.py

@@ -2,6 +2,9 @@ import random
 from eth2spec.test.helpers.block import (
     build_empty_block_for_next_slot,
 )
+from eth2spec.test.helpers.state import (
+    state_transition_and_sign_block,
+)
 from eth2spec.test.lightclient_patch.helpers import (
     compute_aggregate_sync_committee_signature,
 )
@@ -57,3 +60,53 @@ def test_invalid_sync_committee_signature(spec, state):
     yield 'blocks', [block]
     expect_assertion_error(lambda: spec.process_sync_committee(state, block.body))
     yield 'post', None
+
+
+def compute_sync_committee_participant_reward(spec, state, participant_index, active_validator_count, committee_size):
+    base_reward = spec.get_base_reward(state, participant_index)
+    proposer_reward = spec.get_proposer_reward(state, participant_index)
+    max_participant_reward = base_reward - proposer_reward
+    return max_participant_reward * active_validator_count // committee_size // spec.SLOTS_PER_EPOCH
+
+
+@with_all_phases_except([PHASE0, PHASE1])
+@spec_state_test
+def test_sync_committee_rewards(spec, state):
+    committee = spec.get_sync_committee_indices(state, spec.get_current_epoch(state))
+    committee_size = len(committee)
+    active_validator_count = len(spec.get_active_validator_indices(state, spec.get_current_epoch(state)))
+
+    yield 'pre', state
+
+    pre_balances = state.balances.copy()
+
+    block = build_empty_block_for_next_slot(spec, state)
+    block.body.sync_committee_bits = [True] * committee_size
+    block.body.sync_committee_signature = compute_aggregate_sync_committee_signature(
+        spec,
+        state,
+        block.slot - 1,
+        committee,
+    )
+
+    signed_block = state_transition_and_sign_block(spec, state, block)
+
+    yield 'blocks', [signed_block]
+    yield 'post', state
+
+    for index in range(len(state.validators)):
+        expected_reward = 0
+
+        if index == block.proposer_index:
+            expected_reward += sum([spec.get_proposer_reward(state, index) for index in committee])
+
+        if index in committee:
+            expected_reward += compute_sync_committee_participant_reward(
+                spec,
+                state,
+                index,
+                active_validator_count,
+                committee_size
+            )
+
+        assert state.balances[index] == pre_balances[index] + expected_reward