def test_on_attestation_target_checkpoint_not_in_store_diff_slot(spec, state):
store = get_genesis_forkchoice_store(spec, state)
time = store.time + spec.SECONDS_PER_SLOT * (spec.SLOTS_PER_EPOCH + 1)
spec.on_tick(store, time)
# move to two slots before next epoch to make target block one before an empty slot
next_epoch = spec.get_current_epoch(state) + 1
transition_to(spec, state,
spec.compute_start_slot_at_epoch(next_epoch) - 2)
target_block = build_empty_block_for_next_slot(spec, state)
signed_target_block = state_transition_and_sign_block(
spec, state, target_block)
# add target block to store
spec.on_block(store, signed_target_block)
# target checkpoint state is not yet in store
attestation_slot = target_block.slot + 1
transition_to(spec, state, attestation_slot)
attestation = get_valid_attestation(spec,
state,
slot=attestation_slot,
signed=True)
assert attestation.data.target.root == target_block.hash_tree_root()
run_on_attestation(spec, state, store, attestation)
def test_on_attestation_beacon_block_not_in_store(spec, state):
store = get_genesis_forkchoice_store(spec, state)
time = store.time + spec.SECONDS_PER_SLOT * (spec.SLOTS_PER_EPOCH + 1)
spec.on_tick(store, time)
# move to immediately before next epoch to make block new target
next_epoch = spec.get_current_epoch(state) + 1
transition_to(spec, state,
spec.compute_start_slot_at_epoch(next_epoch) - 1)
target_block = build_empty_block_for_next_slot(spec, state)
signed_target_block = state_transition_and_sign_block(
spec, state, target_block)
# store target in store
spec.on_block(store, signed_target_block)
head_block = build_empty_block_for_next_slot(spec, state)
state_transition_and_sign_block(spec, state, head_block)
# do not add head block to store
attestation = get_valid_attestation(spec,
state,
slot=head_block.slot,
signed=True)
assert attestation.data.target.root == target_block.hash_tree_root()
assert attestation.data.beacon_block_root == head_block.hash_tree_root()
run_on_attestation(spec, state, store, attestation, False)
def test_on_attestation_inconsistent_target_and_head(spec, state):
store = get_genesis_forkchoice_store(spec, state)
spec.on_tick(store, store.time + 2 * spec.config.SECONDS_PER_SLOT * spec.SLOTS_PER_EPOCH)
# Create chain 1 as empty chain between genesis and start of 1st epoch
target_state_1 = state.copy()
next_epoch(spec, target_state_1)
# Create chain 2 with different block in chain from chain 1 from chain 1 from chain 1 from chain 1
target_state_2 = state.copy()
diff_block = build_empty_block_for_next_slot(spec, target_state_2)
signed_diff_block = state_transition_and_sign_block(spec, target_state_2, diff_block)
spec.on_block(store, signed_diff_block)
next_epoch(spec, target_state_2)
next_slot(spec, target_state_2)
# Create and store block new head block on target state 1
head_block = build_empty_block_for_next_slot(spec, target_state_1)
signed_head_block = state_transition_and_sign_block(spec, target_state_1, head_block)
spec.on_block(store, signed_head_block)
# Attest to head of chain 1
attestation = get_valid_attestation(spec, target_state_1, slot=head_block.slot, signed=False)
epoch = spec.compute_epoch_at_slot(attestation.data.slot)
# Set attestation target to be from chain 2
attestation.data.target = spec.Checkpoint(epoch=epoch, root=spec.get_block_root(target_state_2, epoch))
sign_attestation(spec, state, attestation)
assert attestation.data.target.epoch == spec.GENESIS_EPOCH + 1
assert spec.compute_epoch_at_slot(attestation.data.slot) == spec.GENESIS_EPOCH + 1
assert spec.get_block_root(target_state_1, epoch) != attestation.data.target.root
run_on_attestation(spec, state, store, attestation, False)
def test_on_block_update_justified_checkpoint_within_safe_slots(spec, state):
# Initialization
store = get_genesis_forkchoice_store(spec, state)
time = 0
spec.on_tick(store, time)
next_epoch(spec, state)
spec.on_tick(store, store.time + state.slot * spec.SECONDS_PER_SLOT)
state, store, last_signed_block = apply_next_epoch_with_attestations(spec, state, store)
next_epoch(spec, state)
spec.on_tick(store, store.time + state.slot * spec.SECONDS_PER_SLOT)
last_block_root = hash_tree_root(last_signed_block.message)
# Mock the justified checkpoint
just_state = store.block_states[last_block_root]
new_justified = spec.Checkpoint(
epoch=just_state.current_justified_checkpoint.epoch + 1,
root=b'\x77' * 32,
)
just_state.current_justified_checkpoint = new_justified
block = build_empty_block_for_next_slot(spec, just_state)
signed_block = state_transition_and_sign_block(spec, deepcopy(just_state), block)
assert spec.get_current_slot(store) % spec.SLOTS_PER_EPOCH < spec.SAFE_SLOTS_TO_UPDATE_JUSTIFIED
run_on_block(spec, store, signed_block)
assert store.justified_checkpoint == new_justified
def test_update_justified_single_on_store_finalized_chain(spec, state):
store = get_genesis_forkchoice_store(spec, state)
# [Mock store.best_justified_checkpoint]
# Create a block at epoch 1
next_epoch(spec, state)
block = build_empty_block_for_next_slot(spec, state)
state_transition_and_sign_block(spec, state, block)
store.blocks[block.hash_tree_root()] = block.copy()
store.block_states[block.hash_tree_root()] = state.copy()
parent_block = block.copy()
# To make compute_slots_since_epoch_start(current_slot) == 0, transition to the end of the epoch
slot = state.slot + spec.SLOTS_PER_EPOCH - state.slot % spec.SLOTS_PER_EPOCH - 1
transition_to(spec, state, slot)
# Create a block at the start of epoch 2
block = build_empty_block_for_next_slot(spec, state)
# Mock state
state.current_justified_checkpoint = spec.Checkpoint(
epoch=spec.compute_epoch_at_slot(parent_block.slot),
root=parent_block.hash_tree_root(),
)
state_transition_and_sign_block(spec, state, block)
store.blocks[block.hash_tree_root()] = block
store.block_states[block.hash_tree_root()] = state
# Mock store.best_justified_checkpoint
store.best_justified_checkpoint = state.current_justified_checkpoint.copy()
run_on_tick(spec,
store,
store.genesis_time + state.slot * spec.config.SECONDS_PER_SLOT,
new_justified_checkpoint=True)
def test_shorter_chain_but_heavier_weight(spec, state):
genesis_state = state.copy()
# Initialization
store = get_genesis_forkchoice_store(spec, state)
anchor_root = get_anchor_root(spec, state)
assert spec.get_head(store) == anchor_root
# 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)
add_block_to_store(spec, store, signed_long_block)
# 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)
add_block_to_store(spec, store, signed_short_block)
short_attestation = get_valid_attestation(spec, short_state, short_block.slot, signed=True)
add_attestation_to_store(spec, store, short_attestation)
assert spec.get_head(store) == spec.hash_tree_root(short_block)
def test_no_update_not_epoch_boundary(spec, state):
store = get_genesis_forkchoice_store(spec, state)
store.best_justified_checkpoint = spec.Checkpoint(
epoch=store.justified_checkpoint.epoch + 1,
root=b'\x55' * 32,
)
run_on_tick(spec, store, store.time + spec.config.SECONDS_PER_SLOT)
def test_on_block_future_block(spec, state):
# Initialization
store = get_genesis_forkchoice_store(spec, state)
# do not tick time
# Fail receiving 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)
run_on_block(spec, store, signed_block, False)
def test_on_block_outside_safe_slots_and_multiple_better_justified(
spec, state):
# Initialization
store = get_genesis_forkchoice_store(spec, state)
time = 0
spec.on_tick(store, time)
next_epoch(spec, state)
spec.on_tick(store, store.time + state.slot * spec.SECONDS_PER_SLOT)
state, store, last_signed_block = apply_next_epoch_with_attestations(
spec, state, store)
next_epoch(spec, state)
spec.on_tick(store, store.time + state.slot * spec.SECONDS_PER_SLOT)
last_block_root = hash_tree_root(last_signed_block.message)
# Mock justified block in store
just_block = build_empty_block_for_next_slot(spec, state)
# Slot is same as justified checkpoint so does not trigger an override in the store
just_block.slot = spec.compute_start_slot_at_epoch(
store.justified_checkpoint.epoch)
store.blocks[just_block.hash_tree_root()] = just_block
# Step time past safe slots
spec.on_tick(
store, store.time +
spec.SAFE_SLOTS_TO_UPDATE_JUSTIFIED * spec.SECONDS_PER_SLOT)
assert spec.get_current_slot(
store) % spec.SLOTS_PER_EPOCH >= spec.SAFE_SLOTS_TO_UPDATE_JUSTIFIED
previously_justified = store.justified_checkpoint
# Add a series of new blocks with "better" justifications
best_justified_checkpoint = spec.Checkpoint(epoch=0)
for i in range(3, 0, -1):
just_state = store.block_states[last_block_root]
new_justified = spec.Checkpoint(
epoch=previously_justified.epoch + i,
root=just_block.hash_tree_root(),
)
if new_justified.epoch > best_justified_checkpoint.epoch:
best_justified_checkpoint = new_justified
just_state.current_justified_checkpoint = new_justified
block = build_empty_block_for_next_slot(spec, just_state)
signed_block = state_transition_and_sign_block(spec,
deepcopy(just_state),
block)
run_on_block(spec, store, signed_block)
assert store.justified_checkpoint == previously_justified
# ensure the best from the series was stored
assert store.best_justified_checkpoint == best_justified_checkpoint
def test_on_attestation_same_slot(spec, state):
store = get_genesis_forkchoice_store(spec, state)
time = store.time + spec.config.SECONDS_PER_SLOT
spec.on_tick(store, time)
block = build_empty_block_for_next_slot(spec, state)
signed_block = state_transition_and_sign_block(spec, state, block)
spec.on_block(store, signed_block)
attestation = get_valid_attestation(spec, state, slot=block.slot, signed=True)
run_on_attestation(spec, state, store, attestation, False)
def test_update_justified_single(spec, state):
store = get_genesis_forkchoice_store(spec, state)
next_epoch = spec.get_current_epoch(state) + 1
next_epoch_start_slot = spec.compute_start_slot_at_epoch(next_epoch)
seconds_until_next_epoch = next_epoch_start_slot * spec.SECONDS_PER_SLOT - store.time
store.best_justified_checkpoint = spec.Checkpoint(
epoch=store.justified_checkpoint.epoch + 1,
root=b'\x55' * 32,
)
run_on_tick(spec, store, store.time + seconds_until_next_epoch, True)
def initialize_store(spec, state, shards):
store = get_genesis_forkchoice_store(spec, state)
anchor_root = get_anchor_root(spec, state)
assert spec.get_head(store) == anchor_root
for shard in shards:
shard_head_root = spec.get_shard_head(store, shard)
assert shard_head_root == state.shard_states[shard].latest_block_root
shard_store = store.shard_stores[shard]
assert shard_store.block_states[shard_head_root].slot == 0
assert shard_store.block_states[shard_head_root] == state.shard_states[shard]
return store
def test_no_update_same_slot_at_epoch_boundary(spec, state):
store = get_genesis_forkchoice_store(spec, state)
seconds_per_epoch = spec.config.SECONDS_PER_SLOT * spec.SLOTS_PER_EPOCH
store.best_justified_checkpoint = spec.Checkpoint(
epoch=store.justified_checkpoint.epoch + 1,
root=b'\x55' * 32,
)
# set store time to already be at epoch boundary
store.time = seconds_per_epoch
run_on_tick(spec, store, store.time + 1)
def test_on_block_outside_safe_slots_but_finality(spec, state):
# Initialization
store = get_genesis_forkchoice_store(spec, state)
time = 100
spec.on_tick(store, time)
next_epoch(spec, state)
spec.on_tick(store, store.time + state.slot * spec.SECONDS_PER_SLOT)
state, store, last_signed_block = apply_next_epoch_with_attestations(spec, state, store)
last_block_root = hash_tree_root(last_signed_block.message)
# Mock fictitious justified checkpoint in store
store.justified_checkpoint = spec.Checkpoint(
epoch=spec.compute_epoch_at_slot(last_signed_block.message.slot),
root=spec.Root("0x4a55535449464945440000000000000000000000000000000000000000000000")
)
next_epoch(spec, state)
spec.on_tick(store, store.time + state.slot * spec.SECONDS_PER_SLOT)
# Create new higher justified checkpoint not in branch of store's justified checkpoint
just_block = build_empty_block_for_next_slot(spec, state)
store.blocks[just_block.hash_tree_root()] = just_block
# Step time past safe slots
spec.on_tick(store, store.time + spec.SAFE_SLOTS_TO_UPDATE_JUSTIFIED * spec.SECONDS_PER_SLOT)
assert spec.get_current_slot(store) % spec.SLOTS_PER_EPOCH >= spec.SAFE_SLOTS_TO_UPDATE_JUSTIFIED
# Mock justified and finalized update in state
just_fin_state = store.block_states[last_block_root]
new_justified = spec.Checkpoint(
epoch=spec.compute_epoch_at_slot(just_block.slot) + 1,
root=just_block.hash_tree_root(),
)
assert new_justified.epoch > store.justified_checkpoint.epoch
new_finalized = spec.Checkpoint(
epoch=spec.compute_epoch_at_slot(just_block.slot),
root=just_block.parent_root,
)
assert new_finalized.epoch > store.finalized_checkpoint.epoch
just_fin_state.current_justified_checkpoint = new_justified
just_fin_state.finalized_checkpoint = new_finalized
# Build and add block that includes the new justified/finalized info
block = build_empty_block_for_next_slot(spec, just_fin_state)
signed_block = state_transition_and_sign_block(spec, deepcopy(just_fin_state), block)
run_on_block(spec, store, signed_block)
assert store.finalized_checkpoint == new_finalized
assert store.justified_checkpoint == new_justified
def test_on_block_outside_safe_slots_but_finality(spec, state):
# Initialization
store = get_genesis_forkchoice_store(spec, state)
time = 100
spec.on_tick(store, time)
next_epoch(spec, state)
spec.on_tick(store, store.time + state.slot * spec.SECONDS_PER_SLOT)
state, store, last_signed_block = apply_next_epoch_with_attestations(
spec, state, store)
next_epoch(spec, state)
spec.on_tick(store, store.time + state.slot * spec.SECONDS_PER_SLOT)
last_block_root = hash_tree_root(last_signed_block.message)
# Mock justified block in store
just_block = build_empty_block_for_next_slot(spec, state)
# Slot is same as justified checkpoint so does not trigger an override in the store
just_block.slot = spec.compute_start_slot_at_epoch(
store.justified_checkpoint.epoch)
store.blocks[just_block.hash_tree_root()] = just_block
# Step time past safe slots
spec.on_tick(
store, store.time +
spec.SAFE_SLOTS_TO_UPDATE_JUSTIFIED * spec.SECONDS_PER_SLOT)
assert spec.get_current_slot(
store) % spec.SLOTS_PER_EPOCH >= spec.SAFE_SLOTS_TO_UPDATE_JUSTIFIED
# Mock justified and finalized update in state
just_fin_state = store.block_states[last_block_root]
new_justified = spec.Checkpoint(
epoch=store.justified_checkpoint.epoch + 1,
root=just_block.hash_tree_root(),
)
new_finalized = spec.Checkpoint(
epoch=store.finalized_checkpoint.epoch + 1,
root=just_block.parent_root,
)
just_fin_state.current_justified_checkpoint = new_justified
just_fin_state.finalized_checkpoint = new_finalized
# Build and add block that includes the new justified/finalized info
block = build_empty_block_for_next_slot(spec, just_fin_state)
signed_block = state_transition_and_sign_block(spec,
deepcopy(just_fin_state),
block)
run_on_block(spec, store, signed_block)
assert store.finalized_checkpoint == new_finalized
assert store.justified_checkpoint == new_justified
def test_on_block_before_finalized(spec, state):
# Initialization
store = get_genesis_forkchoice_store(spec, state)
time = 100
spec.on_tick(store, time)
store.finalized_checkpoint = spec.Checkpoint(
epoch=store.finalized_checkpoint.epoch + 2,
root=store.finalized_checkpoint.root)
# Fail receiving 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)
run_on_block(spec, store, signed_block, False)
def test_on_attestation_invalid_attestation(spec, state):
store = get_genesis_forkchoice_store(spec, state)
time = store.time + 3 * spec.config.SECONDS_PER_SLOT
spec.on_tick(store, time)
block = build_empty_block_for_next_slot(spec, state)
signed_block = state_transition_and_sign_block(spec, state, block)
spec.on_block(store, signed_block)
attestation = get_valid_attestation(spec, state, slot=block.slot, signed=True)
# make invalid by using an invalid committee index
attestation.data.index = spec.MAX_COMMITTEES_PER_SLOT * spec.SLOTS_PER_EPOCH
run_on_attestation(spec, state, store, attestation, False)
def test_on_attestation_previous_epoch(spec, state):
store = get_genesis_forkchoice_store(spec, state)
spec.on_tick(store, store.time + spec.config.SECONDS_PER_SLOT * spec.SLOTS_PER_EPOCH)
block = build_empty_block_for_next_slot(spec, state)
signed_block = state_transition_and_sign_block(spec, state, block)
# store block in store
spec.on_block(store, signed_block)
attestation = get_valid_attestation(spec, state, slot=block.slot, signed=True)
assert attestation.data.target.epoch == spec.GENESIS_EPOCH
assert spec.compute_epoch_at_slot(spec.get_current_slot(store)) == spec.GENESIS_EPOCH + 1
run_on_attestation(spec, state, store, attestation)
def test_no_update_new_justified_later_epoch(spec, state):
store = get_genesis_forkchoice_store(spec, state)
seconds_per_epoch = spec.config.SECONDS_PER_SLOT * spec.SLOTS_PER_EPOCH
store.best_justified_checkpoint = spec.Checkpoint(
epoch=store.justified_checkpoint.epoch + 1,
root=b'\x55' * 32,
)
store.justified_checkpoint = spec.Checkpoint(
epoch=store.best_justified_checkpoint.epoch + 1,
root=b'\44' * 32,
)
run_on_tick(spec, store, store.time + seconds_per_epoch)
def test_on_block_finalized_skip_slots(spec, state):
# Initialization
store = get_genesis_forkchoice_store(spec, state)
time = 100
spec.on_tick(store, time)
store.finalized_checkpoint = spec.Checkpoint(
epoch=store.finalized_checkpoint.epoch + 2,
root=store.finalized_checkpoint.root
)
# Build block that includes the skipped slots up to finality in chain
block = build_empty_block(spec, state, spec.compute_start_slot_at_epoch(store.finalized_checkpoint.epoch) + 2)
signed_block = state_transition_and_sign_block(spec, state, block)
spec.on_tick(store, store.time + state.slot * spec.SECONDS_PER_SLOT)
run_on_block(spec, store, signed_block)
def test_on_block_bad_parent_root(spec, state):
# Initialization
store = get_genesis_forkchoice_store(spec, state)
time = 100
spec.on_tick(store, time)
# Fail receiving block of `GENESIS_SLOT + 1` slot
block = build_empty_block_for_next_slot(spec, state)
transition_unsigned_block(spec, state, block)
block.state_root = state.hash_tree_root()
block.parent_root = b'\x45' * 32
signed_block = sign_block(spec, state, block)
run_on_block(spec, store, signed_block, False)
def test_on_attestation_future_block(spec, state):
store = get_genesis_forkchoice_store(spec, state)
time = store.time + spec.config.SECONDS_PER_SLOT * 5
spec.on_tick(store, time)
block = build_empty_block_for_next_slot(spec, state)
signed_block = state_transition_and_sign_block(spec, state, block)
spec.on_block(store, signed_block)
# attestation for slot immediately prior to the block being attested to
attestation = get_valid_attestation(spec, state, slot=block.slot - 1, signed=False)
attestation.data.beacon_block_root = block.hash_tree_root()
sign_attestation(spec, state, attestation)
run_on_attestation(spec, state, store, attestation, False)
def test_on_attestation_future_epoch(spec, state):
store = get_genesis_forkchoice_store(spec, state)
time = store.time + 3 * spec.config.SECONDS_PER_SLOT
spec.on_tick(store, time)
block = build_empty_block_for_next_slot(spec, state)
signed_block = state_transition_and_sign_block(spec, state, block)
# store block in store
spec.on_block(store, signed_block)
# move state forward but not store
next_epoch(spec, state)
attestation = get_valid_attestation(spec, state, slot=state.slot, signed=True)
run_on_attestation(spec, state, store, attestation, False)
def test_chain_no_attestations(spec, state):
# Initialization
store = get_genesis_forkchoice_store(spec, state)
anchor_root = get_anchor_root(spec, state)
assert spec.get_head(store) == anchor_root
# 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)
add_block_to_store(spec, store, signed_block_1)
# 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)
add_block_to_store(spec, store, signed_block_2)
assert spec.get_head(store) == spec.hash_tree_root(block_2)
def test_on_attestation_past_epoch(spec, state):
store = get_genesis_forkchoice_store(spec, state)
# move time forward 2 epochs
time = store.time + 2 * spec.config.SECONDS_PER_SLOT * spec.SLOTS_PER_EPOCH
spec.on_tick(store, time)
# create and store block from 3 epochs ago
block = build_empty_block_for_next_slot(spec, state)
signed_block = state_transition_and_sign_block(spec, state, block)
spec.on_block(store, signed_block)
# create attestation for past block
attestation = get_valid_attestation(spec, state, slot=state.slot, signed=True)
assert attestation.data.target.epoch == spec.GENESIS_EPOCH
assert spec.compute_epoch_at_slot(spec.get_current_slot(store)) == spec.GENESIS_EPOCH + 2
run_on_attestation(spec, state, store, attestation, False)
def test_basic(spec, state):
# Initialization
store = get_genesis_forkchoice_store(spec, state)
time = 100
spec.on_tick(store, time)
assert store.time == 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)
run_on_block(spec, store, signed_block)
# On receiving a block of next epoch
store.time = time + spec.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)
run_on_block(spec, store, signed_block)
def test_on_block_checkpoints(spec, state):
# Initialization
store = get_genesis_forkchoice_store(spec, state)
time = 100
spec.on_tick(store, time)
next_epoch(spec, state)
spec.on_tick(store, store.time + state.slot * spec.SECONDS_PER_SLOT)
state, store, last_signed_block = apply_next_epoch_with_attestations(spec, state, store)
next_epoch(spec, state)
spec.on_tick(store, store.time + state.slot * spec.SECONDS_PER_SLOT)
last_block_root = hash_tree_root(last_signed_block.message)
# Mock the finalized_checkpoint
fin_state = store.block_states[last_block_root]
fin_state.finalized_checkpoint = (
store.block_states[last_block_root].current_justified_checkpoint
)
block = build_empty_block_for_next_slot(spec, fin_state)
signed_block = state_transition_and_sign_block(spec, deepcopy(fin_state), block)
run_on_block(spec, store, signed_block)
def test_split_tie_breaker_no_attestations(spec, state):
genesis_state = state.copy()
# Initialization
store = get_genesis_forkchoice_store(spec, state)
anchor_root = get_anchor_root(spec, state)
assert spec.get_head(store) == anchor_root
# 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)
add_block_to_store(spec, store, signed_block_1)
# 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)
add_block_to_store(spec, store, signed_block_2)
highest_root = max(spec.hash_tree_root(block_1), spec.hash_tree_root(block_2))
assert spec.get_head(store) == highest_root
def test_genesis(spec, state):
# Initialization
store = get_genesis_forkchoice_store(spec, state)
anchor_root = get_anchor_root(spec, state)
assert spec.get_head(store) == anchor_root
def test_filtered_block_tree(spec, state):
# Initialization
store = get_genesis_forkchoice_store(spec, state)
anchor_root = get_anchor_root(spec, state)
# transition state past initial couple of epochs
next_epoch(spec, state)
next_epoch(spec, state)
assert spec.get_head(store) == anchor_root
# fill in attestations for entire epoch, justifying the recent epoch
prev_state, signed_blocks, state = next_epoch_with_attestations(spec, state, True, False)
attestations = [
attestation for signed_block in signed_blocks
for attestation in signed_block.message.body.attestations
]
assert state.current_justified_checkpoint.epoch > prev_state.current_justified_checkpoint.epoch
# tick time forward and add blocks and attestations to store
current_time = state.slot * spec.SECONDS_PER_SLOT + store.genesis_time
spec.on_tick(store, current_time)
for signed_block in signed_blocks:
spec.on_block(store, signed_block)
for attestation in attestations:
spec.on_attestation(store, attestation)
assert store.justified_checkpoint == state.current_justified_checkpoint
# the last block in the branch should be the head
expected_head_root = spec.hash_tree_root(signed_blocks[-1].message)
assert spec.get_head(store) == expected_head_root
#
# create branch containing the justified block but not containing enough on
# chain votes to justify that block
#
# build a chain without attestations off of previous justified block
non_viable_state = store.block_states[store.justified_checkpoint.root].copy()
# ensure that next wave of votes are for future epoch
next_epoch(spec, non_viable_state)
next_epoch(spec, non_viable_state)
next_epoch(spec, non_viable_state)
assert spec.get_current_epoch(non_viable_state) > store.justified_checkpoint.epoch
# create rogue block that will be attested to in this non-viable branch
rogue_block = build_empty_block_for_next_slot(spec, non_viable_state)
signed_rogue_block = state_transition_and_sign_block(spec, non_viable_state, rogue_block)
# create an epoch's worth of attestations for the rogue block
next_epoch(spec, non_viable_state)
attestations = []
for i in range(spec.SLOTS_PER_EPOCH):
slot = rogue_block.slot + i
for index in range(spec.get_committee_count_per_slot(non_viable_state, spec.compute_epoch_at_slot(slot))):
attestation = get_valid_attestation(spec, non_viable_state, slot, index, signed=True)
attestations.append(attestation)
# tick time forward to be able to include up to the latest attestation
current_time = (attestations[-1].data.slot + 1) * spec.SECONDS_PER_SLOT + store.genesis_time
spec.on_tick(store, current_time)
# include rogue block and associated attestations in the store
spec.on_block(store, signed_rogue_block)
for attestation in attestations:
spec.on_attestation(store, attestation)
# ensure that get_head still returns the head from the previous branch
assert spec.get_head(store) == expected_head_root
