def test_chain_no_attestations(spec, state):
test_steps = []
# Initialization
store, anchor_block = get_genesis_forkchoice_store_and_block(spec, state)
yield 'anchor_state', state
yield 'anchor_block', anchor_block
anchor_root = get_anchor_root(spec, state)
assert spec.get_head(store) == anchor_root
test_steps.append(
{'checks': {
'head': get_formatted_head_output(spec, store),
}})
# On receiving a block of `GENESIS_SLOT + 1` slot
block_1 = build_empty_block_for_next_slot(spec, state)
signed_block_1 = state_transition_and_sign_block(spec, state, block_1)
yield from tick_and_add_block(spec, store, signed_block_1, test_steps)
# On receiving a block of next epoch
block_2 = build_empty_block_for_next_slot(spec, state)
signed_block_2 = state_transition_and_sign_block(spec, state, block_2)
yield from tick_and_add_block(spec, store, signed_block_2, test_steps)
assert spec.get_head(store) == spec.hash_tree_root(block_2)
test_steps.append(
{'checks': {
'head': get_formatted_head_output(spec, store),
}})
yield 'steps', test_steps
def test_shorter_chain_but_heavier_weight(spec, state):
test_steps = []
genesis_state = state.copy()
# Initialization
store, anchor_block = get_genesis_forkchoice_store_and_block(spec, state)
yield 'anchor_state', state
yield 'anchor_block', anchor_block
anchor_root = get_anchor_root(spec, state)
assert spec.get_head(store) == anchor_root
test_steps.append(
{'checks': {
'head': get_formatted_head_output(spec, store),
}})
# build longer tree
long_state = genesis_state.copy()
for _ in range(3):
long_block = build_empty_block_for_next_slot(spec, long_state)
signed_long_block = state_transition_and_sign_block(
spec, long_state, long_block)
yield from tick_and_add_block(spec, store, signed_long_block,
test_steps)
# build short tree
short_state = genesis_state.copy()
short_block = build_empty_block_for_next_slot(spec, short_state)
short_block.body.graffiti = b'\x42' * 32
signed_short_block = state_transition_and_sign_block(
spec, short_state, short_block)
yield from tick_and_add_block(spec, store, signed_short_block, test_steps)
# Since the long chain has higher proposer_score at slot 1, the latest long block is the head
assert spec.get_head(store) == spec.hash_tree_root(long_block)
short_attestation = get_valid_attestation(spec,
short_state,
short_block.slot,
signed=True)
yield from tick_and_run_on_attestation(spec, store, short_attestation,
test_steps)
assert spec.get_head(store) == spec.hash_tree_root(short_block)
test_steps.append(
{'checks': {
'head': get_formatted_head_output(spec, store),
}})
yield 'steps', test_steps
def test_on_block_before_finalized(spec, state):
test_steps = []
# Initialization
store, anchor_block = get_genesis_forkchoice_store_and_block(spec, state)
yield 'anchor_state', state
yield 'anchor_block', anchor_block
current_time = state.slot * spec.config.SECONDS_PER_SLOT + store.genesis_time
on_tick_and_append_step(spec, store, current_time, test_steps)
assert store.time == current_time
# Fork
another_state = state.copy()
# Create a finalized chain
for _ in range(4):
state, store, _ = yield from apply_next_epoch_with_attestations(
spec, state, store, True, False, test_steps=test_steps)
assert store.finalized_checkpoint.epoch == 2
# Fail receiving block of `GENESIS_SLOT + 1` slot
block = build_empty_block_for_next_slot(spec, another_state)
block.body.graffiti = b'\x12' * 32
signed_block = state_transition_and_sign_block(spec, another_state, block)
assert signed_block.message.hash_tree_root() not in store.blocks
yield from tick_and_add_block(spec,
store,
signed_block,
test_steps,
valid=False)
yield 'steps', test_steps
def test_on_block_update_justified_checkpoint_within_safe_slots(spec, state):
"""
Test `should_update_justified_checkpoint`:
compute_slots_since_epoch_start(get_current_slot(store)) < SAFE_SLOTS_TO_UPDATE_JUSTIFIED
"""
test_steps = []
# Initialization
store, anchor_block = get_genesis_forkchoice_store_and_block(spec, state)
yield 'anchor_state', state
yield 'anchor_block', anchor_block
current_time = state.slot * spec.config.SECONDS_PER_SLOT + store.genesis_time
on_tick_and_append_step(spec, store, current_time, test_steps)
assert store.time == current_time
# Skip epoch 0 & 1
for _ in range(2):
next_epoch(spec, state)
# Fill epoch 2
state, store, _ = yield from apply_next_epoch_with_attestations(
spec, state, store, True, False, test_steps=test_steps)
assert state.finalized_checkpoint.epoch == store.finalized_checkpoint.epoch == 0
assert state.current_justified_checkpoint.epoch == store.justified_checkpoint.epoch == 2
# Skip epoch 3 & 4
for _ in range(2):
next_epoch(spec, state)
# Epoch 5: Attest current epoch
state, store, _ = yield from apply_next_epoch_with_attestations(
spec,
state,
store,
True,
False,
participation_fn=_drop_random_one_third,
test_steps=test_steps)
assert state.finalized_checkpoint.epoch == store.finalized_checkpoint.epoch == 0
assert state.current_justified_checkpoint.epoch == 2
assert store.justified_checkpoint.epoch == 2
assert state.current_justified_checkpoint == store.justified_checkpoint
# Skip epoch 6
next_epoch(spec, state)
pre_state = state.copy()
# Build a block to justify epoch 5
signed_block = state_transition_with_full_block(spec, state, True, True)
assert state.finalized_checkpoint.epoch == 0
assert state.current_justified_checkpoint.epoch == 5
assert state.current_justified_checkpoint.epoch > store.justified_checkpoint.epoch
assert spec.get_current_slot(
store) % spec.SLOTS_PER_EPOCH < spec.SAFE_SLOTS_TO_UPDATE_JUSTIFIED
# Run on_block
yield from tick_and_add_block(spec, store, signed_block, test_steps)
# Ensure justified_checkpoint has been changed but finality is unchanged
assert store.justified_checkpoint.epoch == 5
assert store.justified_checkpoint == state.current_justified_checkpoint
assert store.finalized_checkpoint.epoch == pre_state.finalized_checkpoint.epoch == 0
yield 'steps', test_steps
def run_func():
block = build_empty_block_for_next_slot(spec, state)
block.body.execution_payload.parent_hash = pow_block.block_hash
signed_block = state_transition_and_sign_block(spec, state, block)
yield from tick_and_add_block(spec,
store,
signed_block,
test_steps,
valid=False,
merge_block=True)
def run_func():
block = build_empty_block_for_next_slot(spec, state)
block.body.execution_payload.parent_hash = pow_block.block_hash
signed_block = state_transition_and_sign_block(spec, state, block)
yield from tick_and_add_block(spec,
store,
signed_block,
test_steps,
merge_block=True)
# valid
assert spec.get_head(store) == signed_block.message.hash_tree_root()
def test_split_tie_breaker_no_attestations(spec, state):
test_steps = []
genesis_state = state.copy()
# Initialization
store, anchor_block = get_genesis_forkchoice_store_and_block(spec, state)
yield 'anchor_state', state
yield 'anchor_block', anchor_block
anchor_root = get_anchor_root(spec, state)
assert spec.get_head(store) == anchor_root
test_steps.append(
{'checks': {
'head': get_formatted_head_output(spec, store),
}})
# block at slot 1
block_1_state = genesis_state.copy()
block_1 = build_empty_block_for_next_slot(spec, block_1_state)
signed_block_1 = state_transition_and_sign_block(spec, block_1_state,
block_1)
yield from tick_and_add_block(spec, store, signed_block_1, test_steps)
# additional block at slot 1
block_2_state = genesis_state.copy()
block_2 = build_empty_block_for_next_slot(spec, block_2_state)
block_2.body.graffiti = b'\x42' * 32
signed_block_2 = state_transition_and_sign_block(spec, block_2_state,
block_2)
yield from tick_and_add_block(spec, store, signed_block_2, test_steps)
highest_root = max(spec.hash_tree_root(block_1),
spec.hash_tree_root(block_2))
assert spec.get_head(store) == highest_root
test_steps.append(
{'checks': {
'head': get_formatted_head_output(spec, store),
}})
yield 'steps', test_steps
def test_basic(spec, state):
test_steps = []
# Initialization
store, anchor_block = get_genesis_forkchoice_store_and_block(spec, state)
yield 'anchor_state', state
yield 'anchor_block', anchor_block
current_time = state.slot * spec.config.SECONDS_PER_SLOT + store.genesis_time
on_tick_and_append_step(spec, store, current_time, test_steps)
assert store.time == current_time
# On receiving a block of `GENESIS_SLOT + 1` slot
block = build_empty_block_for_next_slot(spec, state)
signed_block = state_transition_and_sign_block(spec, state, block)
yield from tick_and_add_block(spec, store, signed_block, test_steps)
assert spec.get_head(store) == signed_block.message.hash_tree_root()
# On receiving a block of next epoch
store.time = current_time + spec.config.SECONDS_PER_SLOT * spec.SLOTS_PER_EPOCH
block = build_empty_block(spec, state, state.slot + spec.SLOTS_PER_EPOCH)
signed_block = state_transition_and_sign_block(spec, state, block)
yield from tick_and_add_block(spec, store, signed_block, test_steps)
assert spec.get_head(store) == signed_block.message.hash_tree_root()
yield 'steps', test_steps
def test_on_block_finalized_skip_slots_not_in_skip_chain(spec, state):
"""
Test case was originally from https://github.com/ethereum/consensus-specs/pull/1579
And then rewrote largely.
"""
test_steps = []
# Initialization
store, anchor_block = get_genesis_forkchoice_store_and_block(spec, state)
yield 'anchor_state', state
yield 'anchor_block', anchor_block
current_time = state.slot * spec.config.SECONDS_PER_SLOT + store.genesis_time
on_tick_and_append_step(spec, store, current_time, test_steps)
assert store.time == current_time
# Fill epoch 0 and the first slot of epoch 1
state, store, _ = yield from apply_next_slots_with_attestations(
spec, state, store, spec.SLOTS_PER_EPOCH, True, False, test_steps)
# Skip the rest slots of epoch 1 and the first slot of epoch 2
next_slots(spec, state, spec.SLOTS_PER_EPOCH)
# Fill epoch 3 and 4
for _ in range(2):
state, store, _ = yield from apply_next_epoch_with_attestations(
spec, state, store, True, True, test_steps=test_steps)
# Now we get finalized epoch 2, where `compute_start_slot_at_epoch(2)` is a skipped slot
assert state.finalized_checkpoint.epoch == store.finalized_checkpoint.epoch == 2
assert store.finalized_checkpoint.root == spec.get_block_root(
state, 1) == spec.get_block_root(state, 2)
assert state.current_justified_checkpoint.epoch == store.justified_checkpoint.epoch == 3
assert store.justified_checkpoint == state.current_justified_checkpoint
# Now build a block after the block of the finalized **root**
# Includes finalized block in chain, but does not include finalized skipped slots
another_state = store.block_states[store.finalized_checkpoint.root].copy()
assert another_state.slot == spec.compute_start_slot_at_epoch(
store.finalized_checkpoint.epoch - 1)
block = build_empty_block_for_next_slot(spec, another_state)
signed_block = state_transition_and_sign_block(spec, another_state, block)
yield from tick_and_add_block(spec,
store,
signed_block,
test_steps,
valid=False)
yield 'steps', test_steps
def test_on_block_checkpoints(spec, state):
test_steps = []
# Initialization
store, anchor_block = get_genesis_forkchoice_store_and_block(spec, state)
yield 'anchor_state', state
yield 'anchor_block', anchor_block
current_time = state.slot * spec.config.SECONDS_PER_SLOT + store.genesis_time
on_tick_and_append_step(spec, store, current_time, test_steps)
assert store.time == current_time
# Run for 1 epoch with full attestations
next_epoch(spec, state)
on_tick_and_append_step(
spec, store,
store.genesis_time + state.slot * spec.config.SECONDS_PER_SLOT,
test_steps)
state, store, last_signed_block = yield from apply_next_epoch_with_attestations(
spec, state, store, True, False, test_steps=test_steps)
last_block_root = hash_tree_root(last_signed_block.message)
assert spec.get_head(store) == last_block_root
# Forward 1 epoch
next_epoch(spec, state)
on_tick_and_append_step(
spec, store,
store.genesis_time + state.slot * spec.config.SECONDS_PER_SLOT,
test_steps)
# Mock the finalized_checkpoint and build a block on it
fin_state = store.block_states[last_block_root].copy()
fin_state.finalized_checkpoint = store.block_states[
last_block_root].current_justified_checkpoint.copy()
block = build_empty_block_for_next_slot(spec, fin_state)
signed_block = state_transition_and_sign_block(spec, fin_state.copy(),
block)
yield from tick_and_add_block(spec, store, signed_block, test_steps)
assert spec.get_head(store) == signed_block.message.hash_tree_root()
yield 'steps', test_steps
def test_new_finalized_slot_is_justified_checkpoint_ancestor(spec, state):
"""
J: Justified
F: Finalized
state:
epoch
[0] <- [1] <- [2] <- [3] <- [4] <- [5]
F J
another_state (forked from state at epoch 3):
└──── [4] <- [5]
F J
"""
test_steps = []
# Initialization
store, anchor_block = get_genesis_forkchoice_store_and_block(spec, state)
yield 'anchor_state', state
yield 'anchor_block', anchor_block
current_time = state.slot * spec.config.SECONDS_PER_SLOT + store.genesis_time
on_tick_and_append_step(spec, store, current_time, test_steps)
assert store.time == current_time
# Process state
next_epoch(spec, state)
state, store, _ = yield from apply_next_epoch_with_attestations(
spec, state, store, False, True, test_steps=test_steps)
state, store, _ = yield from apply_next_epoch_with_attestations(
spec, state, store, True, False, test_steps=test_steps)
next_epoch(spec, state)
for _ in range(2):
state, store, _ = yield from apply_next_epoch_with_attestations(
spec, state, store, False, True, test_steps=test_steps)
assert state.finalized_checkpoint.epoch == store.finalized_checkpoint.epoch == 2
assert state.current_justified_checkpoint.epoch == store.justified_checkpoint.epoch == 4
assert store.justified_checkpoint == state.current_justified_checkpoint
# Create another chain
# Forking from epoch 3
all_blocks = []
slot = spec.compute_start_slot_at_epoch(3)
block_root = spec.get_block_root_at_slot(state, slot)
another_state = store.block_states[block_root].copy()
for _ in range(2):
_, signed_blocks, another_state = next_epoch_with_attestations(
spec, another_state, True, True)
all_blocks += signed_blocks
assert another_state.finalized_checkpoint.epoch == 3
assert another_state.current_justified_checkpoint.epoch == 4
pre_store_justified_checkpoint_root = store.justified_checkpoint.root
for block in all_blocks:
yield from tick_and_add_block(spec, store, block, test_steps)
finalized_slot = spec.compute_start_slot_at_epoch(
store.finalized_checkpoint.epoch)
ancestor_at_finalized_slot = spec.get_ancestor(
store, pre_store_justified_checkpoint_root, finalized_slot)
assert ancestor_at_finalized_slot == store.finalized_checkpoint.root
assert store.finalized_checkpoint == another_state.finalized_checkpoint
assert store.justified_checkpoint == another_state.current_justified_checkpoint
yield 'steps', test_steps
def test_new_justified_is_later_than_store_justified(spec, state):
"""
J: Justified
F: Finalized
fork_1_state (forked from genesis):
epoch
[0] <- [1] <- [2] <- [3] <- [4]
F J
fork_2_state (forked from fork_1_state's epoch 2):
epoch
└──── [3] <- [4] <- [5] <- [6]
F J
fork_3_state (forked from genesis):
[0] <- [1] <- [2] <- [3] <- [4] <- [5]
F J
"""
# The 1st fork, from genesis
fork_1_state = state.copy()
# The 3rd fork, from genesis
fork_3_state = state.copy()
test_steps = []
# Initialization
store, anchor_block = get_genesis_forkchoice_store_and_block(spec, state)
yield 'anchor_state', state
yield 'anchor_block', anchor_block
current_time = state.slot * spec.config.SECONDS_PER_SLOT + store.genesis_time
on_tick_and_append_step(spec, store, current_time, test_steps)
assert store.time == current_time
# ----- Process fork_1_state
# Skip epoch 0
next_epoch(spec, fork_1_state)
# Fill epoch 1 with previous epoch attestations
fork_1_state, store, _ = yield from apply_next_epoch_with_attestations(
spec, fork_1_state, store, False, True, test_steps=test_steps)
# Fork `fork_2_state` at the start of epoch 2
fork_2_state = fork_1_state.copy()
assert spec.get_current_epoch(fork_2_state) == 2
# Skip epoch 2
next_epoch(spec, fork_1_state)
# # Fill epoch 3 & 4 with previous epoch attestations
for _ in range(2):
fork_1_state, store, _ = yield from apply_next_epoch_with_attestations(
spec, fork_1_state, store, False, True, test_steps=test_steps)
assert fork_1_state.finalized_checkpoint.epoch == store.finalized_checkpoint.epoch == 0
assert fork_1_state.current_justified_checkpoint.epoch == store.justified_checkpoint.epoch == 3
assert store.justified_checkpoint == fork_1_state.current_justified_checkpoint
# ------ fork_2_state: Create a chain to set store.best_justified_checkpoint
# NOTE: The goal is to make `store.best_justified_checkpoint.epoch > store.justified_checkpoint.epoch`
all_blocks = []
# Proposed an empty block at epoch 2, 1st slot
block = build_empty_block_for_next_slot(spec, fork_2_state)
signed_block = state_transition_and_sign_block(spec, fork_2_state, block)
yield from tick_and_add_block(spec, store, signed_block, test_steps)
assert fork_2_state.current_justified_checkpoint.epoch == 0
# Skip to epoch 4
for _ in range(2):
next_epoch(spec, fork_2_state)
assert fork_2_state.current_justified_checkpoint.epoch == 0
# Propose a block at epoch 4, 5th slot
# Propose a block at epoch 5, 5th slot
for _ in range(2):
next_epoch(spec, fork_2_state)
next_slots(spec, fork_2_state, 4)
signed_block = state_transition_with_full_attestations_block(
spec, fork_2_state, True, True)
yield from tick_and_add_block(spec, store, signed_block, test_steps)
assert fork_2_state.current_justified_checkpoint.epoch == 0
# Propose a block at epoch 6, SAFE_SLOTS_TO_UPDATE_JUSTIFIED + 2 slot
next_epoch(spec, fork_2_state)
next_slots(spec, fork_2_state, spec.SAFE_SLOTS_TO_UPDATE_JUSTIFIED + 2)
signed_block = state_transition_with_full_attestations_block(
spec, fork_2_state, True, True)
assert fork_2_state.finalized_checkpoint.epoch == 0
assert fork_2_state.current_justified_checkpoint.epoch == 5
# Check SAFE_SLOTS_TO_UPDATE_JUSTIFIED
time = store.genesis_time + fork_2_state.slot * spec.config.SECONDS_PER_SLOT
on_tick_and_append_step(spec, store, time, test_steps)
assert spec.compute_slots_since_epoch_start(
spec.get_current_slot(store)) >= spec.SAFE_SLOTS_TO_UPDATE_JUSTIFIED
# Run on_block
yield from add_block(spec, store, signed_block, test_steps)
assert store.finalized_checkpoint.epoch == 0
assert store.justified_checkpoint.epoch == 3
assert store.best_justified_checkpoint.epoch == 5
# ------ fork_3_state: Create another chain to test the
# "Update justified if new justified is later than store justified" case
all_blocks = []
for _ in range(3):
next_epoch(spec, fork_3_state)
# epoch 3
_, signed_blocks, fork_3_state = next_epoch_with_attestations(
spec, fork_3_state, True, True)
all_blocks += signed_blocks
assert fork_3_state.finalized_checkpoint.epoch == 0
# epoch 4, attest the first 5 blocks
_, blocks, fork_3_state = next_slots_with_attestations(
spec, fork_3_state, 5, True, True)
all_blocks += blocks.copy()
assert fork_3_state.finalized_checkpoint.epoch == 0
# Propose a block at epoch 5, 5th slot
next_epoch(spec, fork_3_state)
next_slots(spec, fork_3_state, 4)
signed_block = state_transition_with_full_block(spec, fork_3_state, True,
True)
all_blocks.append(signed_block.copy())
assert fork_3_state.finalized_checkpoint.epoch == 0
# Propose a block at epoch 6, 5th slot
next_epoch(spec, fork_3_state)
next_slots(spec, fork_3_state, 4)
signed_block = state_transition_with_full_block(spec, fork_3_state, True,
True)
all_blocks.append(signed_block.copy())
assert fork_3_state.finalized_checkpoint.epoch == 3
assert fork_3_state.current_justified_checkpoint.epoch == 4
# Apply blocks of `fork_3_state` to `store`
for block in all_blocks:
if store.time < spec.compute_time_at_slot(fork_2_state,
block.message.slot):
time = store.genesis_time + block.message.slot * spec.config.SECONDS_PER_SLOT
on_tick_and_append_step(spec, store, time, test_steps)
yield from add_block(spec, store, block, test_steps)
assert store.finalized_checkpoint == fork_3_state.finalized_checkpoint
assert store.justified_checkpoint == fork_3_state.current_justified_checkpoint
assert store.justified_checkpoint != store.best_justified_checkpoint
assert store.best_justified_checkpoint == fork_2_state.current_justified_checkpoint
yield 'steps', test_steps
def test_on_block_outside_safe_slots_but_finality(spec, state):
"""
Test `should_update_justified_checkpoint` case
- compute_slots_since_epoch_start(get_current_slot(store)) > SAFE_SLOTS_TO_UPDATE_JUSTIFIED
- new_justified_checkpoint and store.justified_checkpoint.root are NOT conflicting
Thus should_update_justified_checkpoint returns True.
Part of this script is similar to `test_new_justified_is_later_than_store_justified`.
"""
test_steps = []
# Initialization
store, anchor_block = get_genesis_forkchoice_store_and_block(spec, state)
yield 'anchor_state', state
yield 'anchor_block', anchor_block
current_time = state.slot * spec.config.SECONDS_PER_SLOT + store.genesis_time
on_tick_and_append_step(spec, store, current_time, test_steps)
assert store.time == current_time
# Skip epoch 0
next_epoch(spec, state)
# Fill epoch 1 to 3, attest current epoch
for _ in range(3):
state, store, _ = yield from apply_next_epoch_with_attestations(
spec, state, store, True, False, test_steps=test_steps)
assert state.finalized_checkpoint.epoch == store.finalized_checkpoint.epoch == 2
assert state.current_justified_checkpoint.epoch == store.justified_checkpoint.epoch == 3
# Skip epoch 4-6
for _ in range(3):
next_epoch(spec, state)
# epoch 7
state, store, _ = yield from apply_next_epoch_with_attestations(
spec, state, store, True, True, test_steps=test_steps)
assert state.finalized_checkpoint.epoch == 2
assert state.current_justified_checkpoint.epoch == 7
# epoch 8, attest the first 5 blocks
state, store, _ = yield from apply_next_slots_with_attestations(
spec, state, store, 5, True, True, test_steps)
assert state.finalized_checkpoint.epoch == store.finalized_checkpoint.epoch == 2
assert state.current_justified_checkpoint.epoch == store.justified_checkpoint.epoch == 7
# Propose a block at epoch 9, 5th slot
next_epoch(spec, state)
next_slots(spec, state, 4)
signed_block = state_transition_with_full_attestations_block(
spec, state, True, True)
yield from tick_and_add_block(spec, store, signed_block, test_steps)
assert state.finalized_checkpoint.epoch == store.finalized_checkpoint.epoch == 2
assert state.current_justified_checkpoint.epoch == store.justified_checkpoint.epoch == 7
# Propose an empty block at epoch 10, SAFE_SLOTS_TO_UPDATE_JUSTIFIED + 2 slot
# This block would trigger justification and finality updates on store
next_epoch(spec, state)
next_slots(spec, state, 4)
block = build_empty_block_for_next_slot(spec, state)
signed_block = state_transition_and_sign_block(spec, state, block)
assert state.finalized_checkpoint.epoch == 7
assert state.current_justified_checkpoint.epoch == 8
# Step time past safe slots and run on_block
if store.time < spec.compute_time_at_slot(state,
signed_block.message.slot):
time = store.genesis_time + signed_block.message.slot * spec.config.SECONDS_PER_SLOT
on_tick_and_append_step(spec, store, time, test_steps)
assert spec.get_current_slot(
store) % spec.SLOTS_PER_EPOCH >= spec.SAFE_SLOTS_TO_UPDATE_JUSTIFIED
yield from add_block(spec, store, signed_block, test_steps)
# Ensure justified_checkpoint finality has been changed
assert store.finalized_checkpoint.epoch == 7
assert store.finalized_checkpoint == state.finalized_checkpoint
assert store.justified_checkpoint.epoch == 8
assert store.justified_checkpoint == state.current_justified_checkpoint
yield 'steps', test_steps
def _apply_base_block_a(spec, state, store, test_steps):
# On receiving block A at slot `N`
block = build_empty_block(spec, state, slot=state.slot + 1)
signed_block_a = state_transition_and_sign_block(spec, state, block)
yield from tick_and_add_block(spec, store, signed_block_a, test_steps)
assert spec.get_head(store) == signed_block_a.message.hash_tree_root()
