nimbus-eth2/tests/spec_epoch_processing/test_process_justification_...

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Nim

# beacon_chain
# Copyright (c) 2018 Status Research & Development GmbH
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at http://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at http://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
import
# Standard library
strformat, unittest,
# Vendored packages
stew/bitops2,
# Specs
../../beacon_chain/spec/[datatypes, state_transition_epoch, validator, helpers],
# Internals
../../beacon_chain/[state_transition],
# Test helpers
../mocking/[mock_genesis],
./epoch_utils,
./justification_finalization_helpers,
../testutil
# See diagram: eth2-finalization.png
# (source) https://github.com/protolambda/eth2-docs#justification-and-finalization
# for a visualization of finalization rules
proc finalizeOn234(state: var BeaconState, epoch: Epoch, sufficient_support: bool) =
## Check finalization on rule 1 "234"
doAssert epoch > 4
state.slot = Slot((epoch * SLOTS_PER_EPOCH) - 1) # Skip ahead to just before epoch
# 43210 -- epochs ago
# 3210x -- justification bitfields indices
# 11*0. -- justification bitfield contents. . = this epoch, * is being justified now
# checkpoints for epochs ago
let (c1, c2, c3, c4, _) = getCheckpoints(epoch)
putCheckpointsInBlockRoots(state, [c1, c2, c3, c4])
# Save for final checks
let old_finalized = state.finalized_checkpoint
# Mock the state
state.previous_justified_checkpoint = c4
state.current_justified_checkpoint = c3
state.justification_bits = 0'u8 # Bitvector of length 4
# mock 3rd and 4th latest epochs as justified
# indices are pre-shift
state.justification_bits.raiseBit 1
state.justification_bits.raiseBit 2
# mock the 2nd latest epoch as justifiable, with 4th as the source
addMockAttestations(
state,
epoch = epoch - 1,
source = c4,
target = c2,
sufficient_support = sufficient_support
)
# State transition
transitionEpochUntilJustificationFinalization(state)
# Checks
doAssert state.previous_justified_checkpoint == c3 # changed to old current
if sufficient_support:
doAssert state.current_justified_checkpoint == c2 # changed to second latest
doAssert state.finalized_checkpoint == c4 # finalized old previous justified epoch
else:
doAssert state.current_justified_checkpoint == c3 # still old current
doAssert state.finalized_checkpoint == old_finalized # no new finalized checkpoint
proc finalizeOn23(state: var BeaconState, epoch: Epoch, sufficient_support: bool) =
## Check finalization on rule 2 "23"
doAssert epoch > 3
state.slot = Slot((epoch * SLOTS_PER_EPOCH) - 1) # Skip ahead to just before epoch
# 43210 -- epochs ago
# 210xx -- justification bitfields indices preshift
# 3210x -- justification bitfield indices postshift
# 01*0. -- justification bitfield contents. . = this epoch, * is being justified now
# checkpoints for epochs ago
let (c1, c2, c3, _, _) = getCheckpoints(epoch)
putCheckpointsInBlockRoots(state, [c1, c2, c3])
# Save for final checks
let old_finalized = state.finalized_checkpoint
# Mock the state
state.previous_justified_checkpoint = c3
state.current_justified_checkpoint = c3
state.justification_bits = 0'u8 # Bitvector of length 4
# mock 3rd as justified
# indices are pre-shift
state.justification_bits.raiseBit 1
# mock the 2nd latest epoch as justifiable, with 3rd as the source
addMockAttestations(
state,
epoch = epoch - 2,
source = c3,
target = c2,
sufficient_support = sufficient_support
)
# State transition
transitionEpochUntilJustificationFinalization(state)
# Checks
doAssert state.previous_justified_checkpoint == c3 # changed to old current
if sufficient_support:
doAssert state.current_justified_checkpoint == c2 # changed to second latest
doAssert state.finalized_checkpoint == c3 # finalized old previous justified epoch
else:
doAssert state.current_justified_checkpoint == c3 # still old current
doAssert state.finalized_checkpoint == old_finalized # no new finalized checkpoint
proc finalizeOn123(state: var BeaconState, epoch: Epoch, sufficient_support: bool) =
## Check finalization on rule 2 "23"
doAssert epoch > 5
state.slot = Slot((epoch * SLOTS_PER_EPOCH) - 1) # Skip ahead to just before epoch
# 43210 -- epochs ago
# 210xx -- justification bitfields indices preshift
# 3210x -- justification bitfield indices postshift
# 0110*. -- justification bitfield contents. . = this epoch, * is being justified now
# checkpoints for epochs ago
let (c1, c2, c3, c4, c5) = getCheckpoints(epoch)
putCheckpointsInBlockRoots(state, [c1, c2, c3, c4, c5])
# Save for final checks
let old_finalized = state.finalized_checkpoint
# Mock the state
state.previous_justified_checkpoint = c5
state.current_justified_checkpoint = c3
state.justification_bits = 0'u8 # Bitvector of length 4
# mock 3rd as justified
# indices are pre-shift
state.justification_bits.raiseBit 1
# mock the 2nd latest epoch as justifiable, with 5th as the source
addMockAttestations(
state,
epoch = epoch - 2,
source = c5,
target = c2,
sufficient_support = sufficient_support
)
# mock the 1st latest epoch as justifiable with 3rd as source
addMockAttestations(
state,
epoch = epoch - 1,
source = c3,
target = c1,
sufficient_support = sufficient_support
)
# State transition
transitionEpochUntilJustificationFinalization(state)
# Checks
doAssert state.previous_justified_checkpoint == c3 # changed to old current
if sufficient_support:
doAssert state.current_justified_checkpoint == c1 # changed to second latest
doAssert state.finalized_checkpoint == c3 # finalized old previous justified epoch
else:
doAssert state.current_justified_checkpoint == c3 # still old current
doAssert state.finalized_checkpoint == old_finalized # no new finalized checkpoint
proc finalizeOn12(state: var BeaconState, epoch: Epoch, sufficient_support: bool) =
## Check finalization on rule 2 "23"
doAssert epoch > 2
state.slot = Slot((epoch * SLOTS_PER_EPOCH) - 1) # Skip ahead to just before epoch
# 43210 -- epochs ago
# 210xx -- justification bitfields indices preshift
# 3210x -- justification bitfield indices postshift
# 01*0. -- justification bitfield contents. . = this epoch, * is being justified now
# checkpoints for epochs ago
let (c1, c2, _, _, _) = getCheckpoints(epoch)
putCheckpointsInBlockRoots(state, [c1, c2])
# Save for final checks
let old_finalized = state.finalized_checkpoint
# Mock the state
state.previous_justified_checkpoint = c2
state.current_justified_checkpoint = c2
state.justification_bits = 0'u8 # Bitvector of length 4
# mock 3rd as justified
# indices are pre-shift
state.justification_bits.raiseBit 0
# mock the 2nd latest epoch as justifiable, with 3rd as the source
addMockAttestations(
state,
epoch = epoch - 1,
source = c2,
target = c1,
sufficient_support = sufficient_support
)
# State transition
transitionEpochUntilJustificationFinalization(state)
# Checks
doAssert state.previous_justified_checkpoint == c2 # changed to old current
if sufficient_support:
doAssert state.current_justified_checkpoint == c1 # changed to second latest
doAssert state.finalized_checkpoint == c2 # finalized old previous justified epoch
else:
doAssert state.current_justified_checkpoint == c2 # still old current
doAssert state.finalized_checkpoint == old_finalized # no new finalized checkpoint
suite "[Unit - Spec - Epoch processing] Justification and Finalization " & preset():
echo " Finalization rules are detailed at https://github.com/protolambda/eth2-docs#justification-and-finalization"
const NumValidators = uint64(8) * SLOTS_PER_EPOCH
let genesisState = initGenesisState(NumValidators)
doAssert genesisState.validators.len == int NumValidators
var state: BeaconState
template resetState: untyped =
deepCopy(state, genesisState)
test " Rule I - 234 finalization with enough support":
resetState()
finalizeOn234(state, Epoch 5, sufficient_support = true)
test " Rule I - 234 finalization without support":
resetState()
finalizeOn234(state, Epoch 5, sufficient_support = false)
test " Rule II - 23 finalization with enough support":
resetState()
finalizeOn23(state, Epoch 4, sufficient_support = true)
test " Rule II - 23 finalization without support":
resetState()
finalizeOn23(state, Epoch 4, sufficient_support = false)
test " Rule III - 123 finalization with enough support":
resetState()
finalizeOn123(state, Epoch 6, sufficient_support = true)
test " Rule III - 123 finalization without support":
resetState()
finalizeOn123(state, Epoch 6, sufficient_support = false)
test " Rule IV - 12 finalization with enough support":
resetState()
finalizeOn12(state, Epoch 3, sufficient_support = true)
test " Rule IV - 12 finalization without support":
resetState()
finalizeOn12(state, Epoch 3, sufficient_support = false)