ensure that pre-state slot is less than block for all block tests

tests/core/pyspec/eth2spec/test/helpers/block.py

@@ -53,6 +53,7 @@ def sign_block(spec, state, block, proposer_index=None):
 
 
 def transition_unsigned_block(spec, state, block):
+    assert state.slot < block.slot  # Preserve assertion from state transition to avoid strange pre-states from testing
     if state.slot < block.slot:
         spec.process_slots(state, block.slot)
     assert state.latest_block_header.slot < block.slot  # There may not already be a block in this slot or past it.
@@ -60,11 +61,11 @@ def transition_unsigned_block(spec, state, block):
     spec.process_block(state, block)
 
 
-def apply_empty_block(spec, state):
+def apply_empty_block(spec, state, slot=None):
     """
     Transition via an empty block (on current slot, assuming no block has been applied yet).
     """
-    block = build_empty_block(spec, state)
+    block = build_empty_block(spec, state, slot)
     transition_unsigned_block(spec, state, block)
 
 

tests/core/pyspec/eth2spec/test/helpers/state.py

@@ -1,5 +1,5 @@
 from eth2spec.test.context import expect_assertion_error
-from eth2spec.test.helpers.block import sign_block, transition_unsigned_block
+from eth2spec.test.helpers.block import apply_empty_block, sign_block, transition_unsigned_block
 
 
 def get_balance(state, index):
@@ -31,6 +31,15 @@ def transition_to(spec, state, slot):
     assert state.slot == slot
 
 
+def transition_to_slot_via_block(spec, state, slot):
+    """
+    Transition to ``slot`` via an empty block transition
+    """
+    assert state.slot < slot
+    apply_empty_block(spec, state, slot)
+    assert state.slot == slot
+
+
 def next_epoch(spec, state):
     """
     Transition to the start slot of the next epoch
@@ -40,6 +49,13 @@ def next_epoch(spec, state):
         spec.process_slots(state, slot)
 
 
+def next_epoch_via_block(spec, state):
+    """
+    Transition to the start slot of the next epoch via a full block transition
+    """
+    apply_empty_block(spec, state, state.slot + spec.SLOTS_PER_EPOCH - state.slot % spec.SLOTS_PER_EPOCH)
+
+
 def get_state_root(spec, state, slot) -> bytes:
     """
     Return the state root at a recent ``slot``.

tests/core/pyspec/eth2spec/test/phase_0/block_processing/test_process_attestation.py

@@ -15,10 +15,9 @@ from eth2spec.test.helpers.attestations import (
 from eth2spec.test.helpers.state import (
     next_slot,
     next_slots,
-    next_epoch,
-    transition_to,
+    next_epoch_via_block,
+    transition_to_slot_via_block,
 )
-from eth2spec.test.helpers.block import apply_empty_block
 from eth2spec.utils.ssz.ssz_typing import Bitlist
 
 
@@ -47,9 +46,7 @@ def test_success_multi_proposer_index_iterations(spec, state):
 @spec_state_test
 def test_success_previous_epoch(spec, state):
     attestation = get_valid_attestation(spec, state, signed=True, on_time=False)
-    transition_to(spec, state, spec.SLOTS_PER_EPOCH - 1)
-    next_epoch(spec, state)
-    apply_empty_block(spec, state)
+    next_epoch_via_block(spec, state)
 
     yield from run_attestation_processing(spec, state, attestation)
 
@@ -79,8 +76,7 @@ def test_after_epoch_slots(spec, state):
     attestation = get_valid_attestation(spec, state, signed=True, on_time=False)
 
     # increment past latest inclusion slot
-    transition_to(spec, state, state.slot + spec.SLOTS_PER_EPOCH + 1)
-    apply_empty_block(spec, state)
+    transition_to_slot_via_block(spec, state, state.slot + spec.SLOTS_PER_EPOCH + 1)
 
     yield from run_attestation_processing(spec, state, attestation, False)
 
@@ -151,8 +147,8 @@ def test_invalid_index(spec, state):
 @with_all_phases
 @spec_state_test
 def test_mismatched_target_and_slot(spec, state):
-    next_epoch(spec, state)
-    next_epoch(spec, state)
+    next_epoch_via_block(spec, state)
+    next_epoch_via_block(spec, state)
 
     attestation = get_valid_attestation(spec, state, on_time=False)
     attestation.data.slot = attestation.data.slot - spec.SLOTS_PER_EPOCH

tests/core/pyspec/eth2spec/test/phase_0/block_processing/test_process_attester_slashing.py

@@ -5,10 +5,9 @@ from eth2spec.test.context import (
 from eth2spec.test.helpers.attestations import sign_indexed_attestation
 from eth2spec.test.helpers.attester_slashings import get_valid_attester_slashing, \
     get_indexed_attestation_participants, get_attestation_2_data, get_attestation_1_data
-from eth2spec.test.helpers.block import apply_empty_block
 from eth2spec.test.helpers.state import (
     get_balance,
-    next_epoch,
+    next_epoch_via_block,
 )
 
 
@@ -91,8 +90,7 @@ def test_success_double(spec, state):
 @with_all_phases
 @spec_state_test
 def test_success_surround(spec, state):
-    next_epoch(spec, state)
-    apply_empty_block(spec, state)
+    next_epoch_via_block(spec, state)
 
     state.current_justified_checkpoint.epoch += 1
     attester_slashing = get_valid_attester_slashing(spec, state, signed_1=False, signed_2=True)

tests/core/pyspec/eth2spec/test/phase_1/block_processing/test_process_early_derived_secret_reveal.py

@@ -1,6 +1,5 @@
 from eth2spec.test.helpers.custody import get_valid_early_derived_secret_reveal
-from eth2spec.test.helpers.block import apply_empty_block
-from eth2spec.test.helpers.state import next_epoch, get_balance
+from eth2spec.test.helpers.state import next_epoch_via_block, get_balance
 from eth2spec.test.context import (
     PHASE0,
     with_all_phases_except,
@@ -64,8 +63,7 @@ def test_reveal_from_current_epoch(spec, state):
 @spec_state_test
 @never_bls
 def test_reveal_from_past_epoch(spec, state):
-    next_epoch(spec, state)
-    apply_empty_block(spec, state)
+    next_epoch_via_block(spec, state)
     randao_key_reveal = get_valid_early_derived_secret_reveal(spec, state, spec.get_current_epoch(state) - 1)
 
     yield from run_early_derived_secret_reveal_processing(spec, state, randao_key_reveal, False)

tests/core/pyspec/eth2spec/test/sanity/test_blocks.py

@@ -2,7 +2,10 @@ from copy import deepcopy
 
 from eth2spec.utils import bls
 
-from eth2spec.test.helpers.state import get_balance, state_transition_and_sign_block, next_slot, next_epoch
+from eth2spec.test.helpers.state import (
+    get_balance, state_transition_and_sign_block,
+    next_slot, next_epoch, next_epoch_via_block,
+)
 from eth2spec.test.helpers.block import (
     build_empty_block_for_next_slot, build_empty_block,
     sign_block,
@@ -48,10 +51,12 @@ def test_same_slot_block_transition(spec, state):
 
     yield 'pre', state
 
-    signed_block = state_transition_and_sign_block(spec, state, block)
+    assert state.slot == block.slot
+
+    signed_block = state_transition_and_sign_block(spec, state, block, expect_fail=True)
 
     yield 'blocks', [signed_block]
-    yield 'post', state
+    yield 'post', None
 
 
 @with_all_phases
@@ -357,22 +362,19 @@ def test_proposer_after_inactive_index(spec, state):
     state.validators[inactive_index].exit_epoch = spec.get_current_epoch(state)
 
     # skip forward, get brand new proposers
-    next_epoch(spec, state)
-    next_epoch(spec, state)
-    block = build_empty_block_for_next_slot(spec, state)
-    state_transition_and_sign_block(spec, state, block)
-
+    next_epoch_via_block(spec, state)
+    next_epoch_via_block(spec, state)
     while True:
-        next_slot(spec, state)
         proposer_index = spec.get_beacon_proposer_index(state)
         if proposer_index > inactive_index:
             # found a proposer that has a higher index than a disabled validator
             yield 'pre', state
             # test if the proposer can be recognized correctly after the inactive validator
-            signed_block = state_transition_and_sign_block(spec, state, build_empty_block(spec, state))
+            signed_block = state_transition_and_sign_block(spec, state, build_empty_block_for_next_slot(spec, state))
             yield 'blocks', [signed_block]
             yield 'post', state
             break
+        next_slot(spec, state)
 
 
 @with_all_phases
@@ -390,16 +392,16 @@ def test_high_proposer_index(spec, state):
 
     active_count = len(spec.get_active_validator_indices(state, current_epoch))
     while True:
-        next_slot(spec, state)
         proposer_index = spec.get_beacon_proposer_index(state)
         if proposer_index >= active_count:
             # found a proposer that has a higher index than the active validator count
             yield 'pre', state
             # test if the proposer can be recognized correctly, even while it has a high index.
-            signed_block = state_transition_and_sign_block(spec, state, build_empty_block(spec, state))
+            signed_block = state_transition_and_sign_block(spec, state, build_empty_block_for_next_slot(spec, state))
             yield 'blocks', [signed_block]
             yield 'post', state
             break
+        next_slot(spec, state)
 
 
 @with_all_phases

tests/core/pyspec/eth2spec/test/test_finality.py

@@ -1,7 +1,6 @@
 from eth2spec.test.context import spec_state_test, never_bls, with_all_phases, with_phases
-from eth2spec.test.helpers.state import next_epoch
+from eth2spec.test.helpers.state import next_epoch_via_block
 from eth2spec.test.helpers.attestations import next_epoch_with_attestations
-from eth2spec.test.helpers.block import apply_empty_block
 
 
 def check_finality(spec,
@@ -58,10 +57,8 @@ def test_finality_no_updates_at_genesis(spec, state):
 @never_bls
 def test_finality_rule_4(spec, state):
     # get past first two epochs that finality does not run on
-    next_epoch(spec, state)
-    apply_empty_block(spec, state)
-    next_epoch(spec, state)
-    apply_empty_block(spec, state)
+    next_epoch_via_block(spec, state)
+    next_epoch_via_block(spec, state)
 
     yield 'pre', state
 
@@ -86,10 +83,8 @@ def test_finality_rule_4(spec, state):
 @never_bls
 def test_finality_rule_1(spec, state):
     # get past first two epochs that finality does not run on
-    next_epoch(spec, state)
-    apply_empty_block(spec, state)
-    next_epoch(spec, state)
-    apply_empty_block(spec, state)
+    next_epoch_via_block(spec, state)
+    next_epoch_via_block(spec, state)
 
     yield 'pre', state
 
@@ -116,10 +111,8 @@ def test_finality_rule_1(spec, state):
 @never_bls
 def test_finality_rule_2(spec, state):
     # get past first two epochs that finality does not run on
-    next_epoch(spec, state)
-    apply_empty_block(spec, state)
-    next_epoch(spec, state)
-    apply_empty_block(spec, state)
+    next_epoch_via_block(spec, state)
+    next_epoch_via_block(spec, state)
 
     yield 'pre', state
 
@@ -152,10 +145,8 @@ def test_finality_rule_3(spec, state):
     https://github.com/ethereum/eth2.0-specs/issues/611#issuecomment-463612892
     """
     # get past first two epochs that finality does not run on
-    next_epoch(spec, state)
-    apply_empty_block(spec, state)
-    next_epoch(spec, state)
-    apply_empty_block(spec, state)
+    next_epoch_via_block(spec, state)
+    next_epoch_via_block(spec, state)
 
     yield 'pre', state