pass on checkpoints working in testing

specs/core/0_beacon-chain.md

@@ -1344,28 +1344,28 @@ def process_justification_and_finalization(state: BeaconState) -> None:
         state, get_matching_target_attestations(state, previous_epoch)
     )
     if previous_epoch_matching_target_balance * 3 >= get_total_active_balance(state) * 2:
-        state.current_justified_checkpoint = Checkpoint(previous_epoch, get_block_root(state, previous_epoch))
+        state.current_justified_checkpoint = Checkpoint(epoch=previous_epoch, root=get_block_root(state, previous_epoch))
         state.justification_bitfield |= (1 << 1)
     current_epoch_matching_target_balance = get_attesting_balance(
         state, get_matching_target_attestations(state, current_epoch)
     )
     if current_epoch_matching_target_balance * 3 >= get_total_active_balance(state) * 2:
-        state.current_justified_checkpoint = Checkpoint(current_epoch, get_block_root(state, current_epoch))
+        state.current_justified_checkpoint = Checkpoint(epoch=current_epoch, root=get_block_root(state, current_epoch))
         state.justification_bitfield |= (1 << 0)
 
     # Process finalizations
     bitfield = state.justification_bitfield
     # The 2nd/3rd/4th most recent epochs are justified, the 2nd using the 4th as source
-    if (bitfield >> 1) % 8 == 0b111 and old_previous_justified_epoch + 3 == current_epoch:
+    if (bitfield >> 1) % 8 == 0b111 and old_previous_justified_checkpoint.epoch + 3 == current_epoch:
         state.finalized_checkpoint = old_previous_justified_checkpoint
     # The 2nd/3rd most recent epochs are justified, the 2nd using the 3rd as source
-    if (bitfield >> 1) % 4 == 0b11 and old_previous_justified_epoch + 2 == current_epoch:
+    if (bitfield >> 1) % 4 == 0b11 and old_previous_justified_checkpoint.epoch+ 2 == current_epoch:
         state.finalized_checkpoint = old_previous_justified_checkpoint
     # The 1st/2nd/3rd most recent epochs are justified, the 1st using the 3rd as source
-    if (bitfield >> 0) % 8 == 0b111 and old_current_justified_epoch + 2 == current_epoch:
+    if (bitfield >> 0) % 8 == 0b111 and old_current_justified_checkpoint.epoch + 2 == current_epoch:
         state.finalized_checkpoint = old_current_justified_checkpoint
     # The 1st/2nd most recent epochs are justified, the 1st using the 2nd as source
-    if (bitfield >> 0) % 4 == 0b11 and old_current_justified_epoch + 1 == current_epoch:
+    if (bitfield >> 0) % 4 == 0b11 and old_current_justified_checkpoint.epoch + 1 == current_epoch:
         state.finalized_checkpoint = old_current_justified_checkpoint
 ```
 

test_libs/pyspec/eth2spec/test/helpers/attestations.py

@@ -24,11 +24,11 @@ def build_attestation_data(spec, state, slot, shard):
         epoch_boundary_root = spec.get_block_root(state, spec.get_current_epoch(state))
 
     if slot < current_epoch_start_slot:
-        justified_epoch = state.previous_justified_epoch
+        source_epoch = state.previous_justified_checkpoint.epoch
-        justified_block_root = state.previous_justified_root
+        source_root = state.previous_justified_checkpoint.root
     else:
-        justified_epoch = state.current_justified_epoch
+        source_epoch = state.current_justified_checkpoint.epoch
-        justified_block_root = state.current_justified_root
+        source_root = state.current_justified_checkpoint.root
 
     if spec.slot_to_epoch(slot) == spec.get_current_epoch(state):
         parent_crosslink = state.current_crosslinks[shard]
@@ -37,10 +37,8 @@ def build_attestation_data(spec, state, slot, shard):
 
     return spec.AttestationData(
         beacon_block_root=block_root,
-        source_epoch=justified_epoch,
+        source_checkpoint=spec.Checkpoint(epoch=source_epoch, root=source_root),
-        source_root=justified_block_root,
+        target_checkpoint=spec.Checkpoint(epoch=spec.slot_to_epoch(slot), root=epoch_boundary_root),
-        target_epoch=spec.slot_to_epoch(slot),
-        target_root=epoch_boundary_root,
         crosslink=spec.Crosslink(
             shard=shard,
             start_epoch=parent_crosslink.end_epoch,
@@ -64,8 +62,8 @@ def get_valid_attestation(spec, state, slot=None, signed=False):
 
     crosslink_committee = spec.get_crosslink_committee(
         state,
-        attestation_data.target_epoch,
+        attestation_data.target_checkpoint.epoch,
-        attestation_data.crosslink.shard
+        attestation_data.crosslink.shard,
     )
 
     committee_size = len(crosslink_committee)
@@ -126,7 +124,7 @@ def get_attestation_signature(spec, state, attestation_data, privkey, custody_bi
         domain=spec.get_domain(
             state=state,
             domain_type=spec.DOMAIN_ATTESTATION,
-            message_epoch=attestation_data.target_epoch,
+            message_epoch=attestation_data.target_checkpoint.epoch,
         )
     )
 
@@ -134,7 +132,7 @@ def get_attestation_signature(spec, state, attestation_data, privkey, custody_bi
 def fill_aggregate_attestation(spec, state, attestation):
     crosslink_committee = spec.get_crosslink_committee(
         state,
-        attestation.data.target_epoch,
+        attestation.data.target_checkpoint.epoch,
         attestation.data.crosslink.shard,
     )
     for i in range(len(crosslink_committee)):

test_libs/pyspec/eth2spec/test/helpers/attester_slashings.py

@@ -7,7 +7,7 @@ def get_valid_attester_slashing(spec, state, signed_1=False, signed_2=False):
     attestation_1 = get_valid_attestation(spec, state, signed=signed_1)
 
     attestation_2 = deepcopy(attestation_1)
-    attestation_2.data.target_root = b'\x01' * 32
+    attestation_2.data.target_checkpoint.root = b'\x01' * 32
 
     if signed_2:
         sign_attestation(spec, state, attestation_2)

test_libs/pyspec/eth2spec/test/phase_0/block_processing/test_process_attestation.py

@@ -38,7 +38,7 @@ def run_attestation_processing(spec, state, attestation, valid=True):
     spec.process_attestation(state, attestation)
 
     # Make sure the attestation has been processed
-    if attestation.data.target_epoch == spec.get_current_epoch(state):
+    if attestation.data.target_checkpoint.epoch == spec.get_current_epoch(state):
         assert len(state.current_epoch_attestations) == current_epoch_count + 1
     else:
         assert len(state.previous_epoch_attestations) == previous_epoch_count + 1
@@ -119,16 +119,16 @@ def test_after_epoch_slots(spec, state):
 @spec_state_test
 def test_old_source_epoch(spec, state):
     state.slot = spec.SLOTS_PER_EPOCH * 5
-    state.finalized_epoch = 2
+    state.finalized_checkpoint.epoch = 2
-    state.previous_justified_epoch = 3
+    state.previous_justified_checkpoint.epoch = 3
-    state.current_justified_epoch = 4
+    state.current_justified_checkpoint.epoch = 4
     attestation = get_valid_attestation(spec, state, slot=(spec.SLOTS_PER_EPOCH * 3) + 1)
 
     # test logic sanity check: make sure the attestation is pointing to oldest known source epoch
-    assert attestation.data.source_epoch == state.previous_justified_epoch
+    assert attestation.data.source_checkpoint.epoch == state.previous_justified_checkpoint.epoch
 
     # Now go beyond that, it will be invalid
-    attestation.data.source_epoch -= 1
+    attestation.data.source_checkpoint.epoch -= 1
 
     sign_attestation(spec, state, attestation)
 
@@ -154,7 +154,7 @@ def test_new_source_epoch(spec, state):
     attestation = get_valid_attestation(spec, state)
     state.slot += spec.MIN_ATTESTATION_INCLUSION_DELAY
 
-    attestation.data.source_epoch += 1
+    attestation.data.source_checkpoint.epoch += 1
 
     sign_attestation(spec, state, attestation)
 
@@ -167,7 +167,7 @@ def test_source_root_is_target_root(spec, state):
     attestation = get_valid_attestation(spec, state)
     state.slot += spec.MIN_ATTESTATION_INCLUSION_DELAY
 
-    attestation.data.source_root = attestation.data.target_root
+    attestation.data.source_checkpoint.root = attestation.data.target_checkpoint.root
 
     sign_attestation(spec, state, attestation)
 
@@ -180,21 +180,18 @@ def test_invalid_current_source_root(spec, state):
     state.slot = spec.SLOTS_PER_EPOCH * 5
     state.finalized_epoch = 2
 
-    state.previous_justified_epoch = 3
+    state.previous_justified_checkpoint = spec.Checkpoint(epoch=3, root=b'\x01'*32)
-    state.previous_justified_root = b'\x01' * 32
+    state.current_justified_checkpoint = spec.Checkpoint(epoch=4, root=b'\x32'*32)
-
-    state.current_justified_epoch = 4
-    state.current_justified_root = b'\xff' * 32
 
     attestation = get_valid_attestation(spec, state, slot=(spec.SLOTS_PER_EPOCH * 3) + 1)
     state.slot += spec.MIN_ATTESTATION_INCLUSION_DELAY
 
     # Test logic sanity checks:
-    assert state.current_justified_root != state.previous_justified_root
+    assert state.current_justified_checkpoint.root != state.previous_justified_checkpoint.root
-    assert attestation.data.source_root == state.previous_justified_root
+    assert attestation.data.source_checkpoint.root == state.previous_justified_checkpoint.root
 
     # Make attestation source root invalid: should be previous justified, not current one
-    attestation.data.source_root = state.current_justified_root
+    attestation.data.source_checkpoint.root = state.current_justified_checkpoint.root
 
     sign_attestation(spec, state, attestation)
 
@@ -207,7 +204,7 @@ def test_bad_source_root(spec, state):
     attestation = get_valid_attestation(spec, state)
     state.slot += spec.MIN_ATTESTATION_INCLUSION_DELAY
 
-    attestation.data.source_root = b'\x42' * 32
+    attestation.data.source_checkpoint.root = b'\x42' * 32
 
     sign_attestation(spec, state, attestation)
 

test_libs/pyspec/eth2spec/test/phase_0/block_processing/test_process_attester_slashing.py

@@ -68,12 +68,14 @@ def test_success_surround(spec, state):
     next_epoch(spec, state)
     apply_empty_block(spec, state)
 
-    state.current_justified_epoch += 1
+    state.current_justified_checkpoint.epoch += 1
     attester_slashing = get_valid_attester_slashing(spec, state, signed_1=False, signed_2=True)
+    attestation_1 = attester_slashing.attestation_1
+    attestation_2 = attester_slashing.attestation_2
 
     # set attestion1 to surround attestation 2
-    attester_slashing.attestation_1.data.source_epoch = attester_slashing.attestation_2.data.source_epoch - 1
+    attestation_1.data.source_checkpoint.epoch = attestation_2.data.source_checkpoint.epoch - 1
-    attester_slashing.attestation_1.data.target_epoch = attester_slashing.attestation_2.data.target_epoch + 1
+    attestation_1.data.target_checkpoint.epoch = attestation_2.data.target_checkpoint.epoch + 1
 
     sign_indexed_attestation(spec, state, attester_slashing.attestation_1)
 
@@ -120,7 +122,7 @@ def test_same_data(spec, state):
 def test_no_double_or_surround(spec, state):
     attester_slashing = get_valid_attester_slashing(spec, state, signed_1=False, signed_2=True)
 
-    attester_slashing.attestation_1.data.target_epoch += 1
+    attester_slashing.attestation_1.data.target_checkpoint.epoch += 1
     sign_indexed_attestation(spec, state, attester_slashing.attestation_1)
 
     yield from run_attester_slashing_processing(spec, state, attester_slashing, False)

test_libs/pyspec/eth2spec/test/phase_0/epoch_processing/test_process_crosslinks.py

@@ -96,7 +96,7 @@ def test_single_crosslink_update_from_previous_epoch(spec, state):
     # ensure rewarded
     for index in spec.get_crosslink_committee(
             state,
-            attestation.data.target_epoch,
+            attestation.data.target_checkpoint.epoch,
             attestation.data.crosslink.shard):
         assert crosslink_deltas[0][index] > 0
         assert crosslink_deltas[1][index] == 0
@@ -148,7 +148,7 @@ def test_double_late_crosslink(spec, state):
     # ensure no reward, only penalties for the failed crosslink
     for index in spec.get_crosslink_committee(
             state,
-            attestation_2.data.target_epoch,
+            attestation_2.data.target_checkpoint.epoch,
             attestation_2.data.crosslink.shard):
         assert crosslink_deltas[0][index] == 0
         assert crosslink_deltas[1][index] > 0

test_libs/pyspec/eth2spec/test/test_finality.py

@@ -14,25 +14,22 @@ def check_finality(spec,
                    previous_justified_changed,
                    finalized_changed):
     if current_justified_changed:
-        assert state.current_justified_epoch > prev_state.current_justified_epoch
+        assert state.current_justified_checkpoint.epoch > prev_state.current_justified_checkpoint.epoch
-        assert state.current_justified_root != prev_state.current_justified_root
+        assert state.current_justified_checkpoint.root != prev_state.current_justified_checkpoint.root
     else:
-        assert state.current_justified_epoch == prev_state.current_justified_epoch
+        assert state.current_justified_checkpoint == prev_state.current_justified_checkpoint
-        assert state.current_justified_root == prev_state.current_justified_root
 
     if previous_justified_changed:
-        assert state.previous_justified_epoch > prev_state.previous_justified_epoch
+        assert state.previous_justified_checkpoint.epoch > prev_state.previous_justified_checkpoint.epoch
-        assert state.previous_justified_root != prev_state.previous_justified_root
+        assert state.previous_justified_checkpoint.root != prev_state.previous_justified_checkpoint.root
     else:
-        assert state.previous_justified_epoch == prev_state.previous_justified_epoch
+        assert state.previous_justified_checkpoint == prev_state.previous_justified_checkpoint
-        assert state.previous_justified_root == prev_state.previous_justified_root
 
     if finalized_changed:
-        assert state.finalized_epoch > prev_state.finalized_epoch
+        assert state.finalized_checkpoint.epoch > prev_state.finalized_checkpoint.epoch
-        assert state.finalized_root != prev_state.finalized_root
+        assert state.finalized_checkpoint.root != prev_state.finalized_checkpoint.root
     else:
-        assert state.finalized_epoch == prev_state.finalized_epoch
+        assert state.finalized_checkpoint == prev_state.finalized_checkpoint
-        assert state.finalized_root == prev_state.finalized_root
 
 
 def next_epoch_with_attestations(spec,
@@ -82,8 +79,7 @@ def test_finality_rule_4(spec, state):
         elif epoch >= 3:
             # rule 4 of finality
             check_finality(spec, state, prev_state, True, True, True)
-            assert state.finalized_epoch == prev_state.current_justified_epoch
+            assert state.finalized_checkpoint == prev_state.current_justified_checkpoint
-            assert state.finalized_root == prev_state.current_justified_root
 
     yield 'blocks', blocks, List[spec.BeaconBlock]
     yield 'post', state
@@ -113,8 +109,7 @@ def test_finality_rule_1(spec, state):
         elif epoch == 2:
             # finalized by rule 1
             check_finality(spec, state, prev_state, True, True, True)
-            assert state.finalized_epoch == prev_state.previous_justified_epoch
+            assert state.finalized_checkpoint == prev_state.previous_justified_checkpoint
-            assert state.finalized_root == prev_state.previous_justified_root
 
     yield 'blocks', blocks, List[spec.BeaconBlock]
     yield 'post', state
@@ -144,8 +139,7 @@ def test_finality_rule_2(spec, state):
             prev_state, new_blocks, state = next_epoch_with_attestations(spec, state, False, True)
             # finalized by rule 2
             check_finality(spec, state, prev_state, True, False, True)
-            assert state.finalized_epoch == prev_state.previous_justified_epoch
+            assert state.finalized_checkpoint == prev_state.previous_justified_checkpoint
-            assert state.finalized_root == prev_state.previous_justified_root
 
         blocks += new_blocks
 
@@ -196,8 +190,7 @@ def test_finality_rule_3(spec, state):
     blocks += new_blocks
     # rule 3
     check_finality(spec, state, prev_state, True, True, True)
-    assert state.finalized_epoch == prev_state.current_justified_epoch
+    assert state.finalized_checkpoint == prev_state.current_justified_checkpoint
-    assert state.finalized_root == prev_state.current_justified_root
 
     yield 'blocks', blocks, List[spec.BeaconBlock]
     yield 'post', state