github.com/gnolang/gno@v0.0.0-20240520182011-228e9d0192ce/tm2/pkg/bft/consensus/state_test.go

package consensus

import (
	"bytes"
	"fmt"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	cstypes "github.com/gnolang/gno/tm2/pkg/bft/consensus/types"
	"github.com/gnolang/gno/tm2/pkg/bft/types"
	"github.com/gnolang/gno/tm2/pkg/events"
	p2pmock "github.com/gnolang/gno/tm2/pkg/p2p/mock"
	"github.com/gnolang/gno/tm2/pkg/random"
	"github.com/gnolang/gno/tm2/pkg/testutils"
)

/*

ProposeSuite
x * TestProposerSelection0 - round robin ordering, round 0
x * TestProposerSelection2 - round robin ordering, round 2++
x * TestEnterProposeNoValidator - timeout into prevote round
x * TestEnterPropose - finish propose without timing out (we have the proposal)
x * TestBadProposal - 2 vals, bad proposal (bad block state hash), should prevote and precommit nil
FullRoundSuite
x * TestFullRound1 - 1 val, full successful round
x * TestFullRoundNil - 1 val, full round of nil
x * TestFullRound2 - 2 vals, both required for full round
LockSuite
x * TestLockNoPOL - 2 vals, 4 rounds. one val locked, precommits nil every round except first.
x * TestLockPOLRelock - 4 vals, one precommits, other 3 polka at next round, so we unlock and precomit the polka
x * TestLockPOLUnlock - 4 vals, one precommits, other 3 polka nil at next round, so we unlock and precomit nil
x * TestLockPOLSafety1 - 4 vals. We shouldn't change lock based on polka at earlier round
x * TestLockPOLSafety2 - 4 vals. After unlocking, we shouldn't relock based on polka at earlier round
MiscSuite
  * TestProposeValidBlock - 4 vals. After unlocking, we should propose the last valid block
  * TestSetValidBlockOnDelayedPrevote
  * TestSetValidBlockOnDelayedProposal
  * TestWaitingTimeoutOnNilPolka
  * TestWaitingTimeoutProposeOnNewRound
  * TestRoundSkipOnNilPolkaFromHigherRound
  * TestWaitTimeoutProposeOnNilPolkaForTheCurrentRound
  * TestEmitNewValidBlockEventOnCommitWithoutBlock
  * TestCommitFromPreviousRound
  * TestStartNextHeightCorrectly
  * TestResetTimeoutPrecommitUponNewHeight
  * TestNetworkLock - once +1/3 precommits, network should be locked XXX ?
  * TestNetworkLockPOL - once +1/3 precommits, the block with more recent polka is committed XXX ?
SlashingSuite
x * TestSlashingPrevotes - a validator prevoting twice in a round gets slashed
x * TestSlashingPrecommits - a validator precomitting twice in a round gets slashed
CatchupSuite
  * TestCatchup - if we might be behind and we've seen any 2/3 prevotes, round skip to new round, precommit, or prevote
HaltSuite
x * TestHalt1 - if we see +2/3 precommits after timing out into new round, we should still commit

*/

// ----------------------------------------------------------------------------------------------------
// ProposeSuite

func TestStateProposerSelection0(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	height, round := cs1.Height, cs1.Round

	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})

	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, proposalCh, newRoundCh)

	// Wait for new round so proposer is set.
	ensureNewRound(newRoundCh, height, round)

	// Wait for complete proposal.
	ensureNewProposal(proposalCh, height, round)

	// Commit a block and ensure proposer for the next height is correct.
	prop := cs1.GetRoundState().Validators.GetProposer()
	address := cs1.privValidator.GetPubKey().Address()
	if prop.Address != address {
		t.Fatalf("expected proposer to be validator %d. Got %X", 0, prop.Address)
	}

	rs := cs1.GetRoundState()
	signAddVotes(cs1, types.PrecommitType, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(), vss[1:]...)

	// Wait for new round so next validator is set.
	ensureNewRound(newRoundCh, height+1, 0)

	prop = cs1.GetRoundState().Validators.GetProposer()
	addr := vss[1].GetPubKey().Address()
	if prop.Address != addr {
		panic(fmt.Sprintf("expected proposer to be validator %d. Got %X", 1, prop.Address))
	}
}

// Now let's do it all again, but starting from round 2 instead of 0
func TestStateProposerSelection2(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4) // test needs more work for more than 3 validators
	height := cs1.Height
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})

	// this time we jump in at round 2
	incrementRound(vss[1:]...)
	incrementRound(vss[1:]...)

	round := 2
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, newRoundCh)

	ensureNewRound(newRoundCh, height, round) // wait for the new round

	// everyone just votes nil. we get a new proposer each round
	for i := 0; i < len(vss); i++ {
		prop := cs1.GetRoundState().Validators.GetProposer()
		addr := vss[(i+round)%len(vss)].GetPubKey().Address()
		correctProposer := addr
		if prop.Address != correctProposer {
			panic(fmt.Sprintf("expected RoundState.Validators.GetProposer() to be validator %d. Got %X", (i+2)%len(vss), prop.Address))
		}

		rs := cs1.GetRoundState()
		signAddVotes(cs1, types.PrecommitType, nil, rs.ProposalBlockParts.Header(), vss[1:]...)
		ensureNewRound(newRoundCh, height, i+round+1) // wait for the new round event each round
		incrementRound(vss[1:]...)
	}
}

// a non-validator should timeout into the prevote round
func TestStateEnterProposeNoPrivValidator(t *testing.T) {
	t.Parallel()

	cs, _ := randConsensusState(1)
	cs.SetPrivValidator(nil)
	height, round := cs.Height, cs.Round

	// Listen for propose timeout event
	timeoutCh := subscribe(cs.evsw, cstypes.EventTimeoutPropose{})

	startFrom(cs, height, round)
	defer func() {
		cs.Stop()
		cs.Wait()
	}()
	defer ensureDrainedChannels(t, timeoutCh)
	// if we're not a validator, EnterPropose should timeout
	ensureNewTimeout(timeoutCh, height, round, cs.config.TimeoutPropose.Nanoseconds())

	if cs.GetRoundState().Proposal != nil {
		t.Error("Expected to make no proposal, since no privValidator")
	}
}

// a validator should not timeout of the prevote round (TODO: unless the block is really big!)
func TestStateEnterProposeYesPrivValidator(t *testing.T) {
	t.Parallel()

	cs, _ := randConsensusState(1)
	height, round := cs.Height, cs.Round

	// Listen for propose timeout event

	newRoundCh := subscribe(cs.evsw, cstypes.EventNewRound{})
	timeoutCh := subscribe(cs.evsw, cstypes.EventTimeoutPropose{})
	proposalCh := subscribe(cs.evsw, cstypes.EventCompleteProposal{})

	startFrom(cs, height, round)
	defer func() {
		cs.Stop()
		cs.Wait()
	}()
	defer ensureDrainedChannels(t, proposalCh, newRoundCh, timeoutCh)

	// Wait for new round so proposer is set.
	ensureNewRound(newRoundCh, height, round)
	ensureNewProposal(proposalCh, height, round)

	// Check that Proposal, ProposalBlock, ProposalBlockParts are set.
	rs := cs.GetRoundState()
	if rs.Proposal == nil {
		t.Error("rs.Proposal should be set")
	}
	if rs.ProposalBlock == nil {
		t.Error("rs.ProposalBlock should be set")
	}
	if rs.ProposalBlockParts.Total() == 0 {
		t.Error("rs.ProposalBlockParts should be set")
	}

	// if we're a validator, enterPropose should not timeout
	ensureNoNewTimeout(timeoutCh, cs.config.TimeoutPropose.Nanoseconds())
}

func TestStateBadProposal(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(2)
	height, round := cs1.Height, cs1.Round
	vs2 := vss[1]

	partSize := types.BlockPartSizeBytes

	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})
	voteCh := subscribe(cs1.evsw, types.EventVote{})

	propBlock, _ := cs1.createProposalBlock() // changeProposer(t, cs1, vs2)

	// make the second validator the proposer by incrementing round
	round++
	incrementRound(vss[1:]...)

	// make the block bad by tampering with statehash
	stateHash := propBlock.AppHash
	if len(stateHash) == 0 {
		stateHash = make([]byte, 32)
	}
	stateHash[0] = (stateHash[0] + 1) % 255
	propBlock.AppHash = stateHash
	propBlockParts := propBlock.MakePartSet(partSize)
	blockID := types.BlockID{Hash: propBlock.Hash(), PartsHeader: propBlockParts.Header()}
	proposal := types.NewProposal(vs2.Height, round, -1, blockID)
	if err := vs2.SignProposal(config.ChainID(), proposal); err != nil {
		t.Fatal("failed to sign bad proposal", err)
	}

	// set the proposal block
	if err := cs1.SetProposalAndBlock(proposal, propBlock, propBlockParts, "some peer"); err != nil {
		t.Fatal(err)
	}

	// start the machine
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, proposalCh, voteCh)

	// wait for proposal
	ensureProposal(proposalCh, height, round, blockID)

	// wait for prevote
	ensurePrevote(voteCh, height, round)
	validatePrevote(cs1, round, vss[0], nil)

	// add bad prevote from vs2 and wait for it
	signAddVotes(cs1, types.PrevoteType, propBlock.Hash(), propBlock.MakePartSet(partSize).Header(), vs2)
	ensurePrevote(voteCh, height, round)

	// wait for precommit
	ensurePrecommit(voteCh, height, round)
	validatePrecommit(t, cs1, round, -1, vss[0], nil, nil)
	signAddVotes(cs1, types.PrecommitType, propBlock.Hash(), propBlock.MakePartSet(partSize).Header(), vs2)
}

// ----------------------------------------------------------------------------------------------------
// FullRoundSuite

// propose, prevote, and precommit a block
func TestStateFullRound1(t *testing.T) {
	t.Parallel()

	cs, vss := randConsensusState(1)
	height, round := cs.Height, cs.Round

	voteCh := subscribe(cs.evsw, types.EventVote{})
	propCh := subscribe(cs.evsw, cstypes.EventCompleteProposal{})
	newRoundCh := subscribe(cs.evsw, cstypes.EventNewRound{})

	// Maybe it would be better to call explicitly StartWithoutWALCatchup().
	startFrom(cs, height, round)
	defer func() {
		cs.Stop()
		cs.Wait()
	}()
	defer ensureDrainedChannels(t, newRoundCh, voteCh, propCh)

	ensureNewRound(newRoundCh, height, round)

	ensureNewProposal(propCh, height, round)

	propBlockHash := cs.GetRoundState().ProposalBlock.Hash()

	ensurePrevote(voteCh, height, round) // wait for prevote
	validatePrevote(cs, round, vss[0], propBlockHash)

	ensurePrecommit(voteCh, height, round) // wait for precommit

	// we're going to roll right into new height
	ensureNewRound(newRoundCh, height+1, 0)

	validateLastPrecommit(cs, vss[0], propBlockHash)
}

// nil is proposed, so prevote and precommit nil
func TestStateFullRoundNil(t *testing.T) {
	t.Parallel()

	cs, vss := randConsensusState(1)
	height, round := cs.Height, cs.Round
	cs.decideProposal = func(height int64, round int) {
		// do nothing.
	}

	voteCh := subscribe(cs.evsw, types.EventVote{})

	startFrom(cs, height, round)
	defer func() {
		cs.Stop()
		cs.Wait()
	}()
	defer ensureDrainedChannels(t, voteCh)

	ensurePrevote(voteCh, height, round)   // prevote
	ensurePrecommit(voteCh, height, round) // precommit

	// should prevote and precommit nil
	validatePrevoteAndPrecommit(t, cs, round, -1, vss[0], nil, nil)
}

// run through propose, prevote, precommit commit with two validators
// where the first validator has to wait for votes from the second
func TestStateFullRound2(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(2)
	vs2 := vss[1]
	height, round := cs1.Height, cs1.Round

	voteCh := subscribe(cs1.evsw, types.EventVote{})
	newBlockCh := subscribe(cs1.evsw, types.EventNewBlock{})

	// start round and wait for propose and prevote
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, voteCh, newBlockCh)

	ensurePrevote(voteCh, height, round) // prevote

	// we should be stuck in limbo waiting for more prevotes
	rs := cs1.GetRoundState()
	propBlockHash, propPartsHeader := rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header()

	// prevote arrives from vs2:
	signAddVotes(cs1, types.PrevoteType, propBlockHash, propPartsHeader, vs2)
	ensurePrevote(voteCh, height, round) // prevote

	ensurePrecommit(voteCh, height, round) // precommit
	// the proposed block should now be locked and our precommit added
	validatePrecommit(t, cs1, 0, 0, vss[0], propBlockHash, propBlockHash)

	// we should be stuck in limbo waiting for more precommits

	// precommit arrives from vs2:
	signAddVotes(cs1, types.PrecommitType, propBlockHash, propPartsHeader, vs2)
	ensurePrecommit(voteCh, height, round)

	// wait to finish commit, propose in next height
	ensureNewBlock(newBlockCh, height)
}

// ------------------------------------------------------------------------------------------
// LockSuite

// two validators, 4 rounds.
// two vals take turns proposing. val1 locks on first one, precommits nil on everything else
func TestStateLockNoPOL(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(2)
	vs2 := vss[1]
	height, round := cs1.Height, cs1.Round

	partSize := types.BlockPartSizeBytes

	timeoutProposeCh := subscribe(cs1.evsw, cstypes.EventTimeoutPropose{})
	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutWait{})
	voteCh := subscribe(cs1.evsw, types.EventVote{})
	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})

	defer ensureDrainedChannels(t, proposalCh, timeoutWaitCh, timeoutProposeCh, newRoundCh, voteCh)

	/*
		Round1 (cs1, B) // B B // B B2
	*/

	// start round and wait for prevote
	startFrom(cs1, height, round)

	ensureNewRound(newRoundCh, height, round)

	ensureNewProposal(proposalCh, height, round)
	ensurePrevote(voteCh, height, round) // prevote
	roundState := cs1.GetRoundState()
	theBlockHash := roundState.ProposalBlock.Hash()
	thePartSetHeader := roundState.ProposalBlockParts.Header()
	validatePrevote(cs1, round, vss[0], theBlockHash)

	// we should now be stuck in limbo forever, waiting for more prevotes
	// prevote arrives from vs2:
	signAddVotes(cs1, types.PrevoteType, theBlockHash, thePartSetHeader, vs2)
	ensurePrevote(voteCh, height, round)   // prevote
	ensurePrecommit(voteCh, height, round) // precommit

	// the proposed block should now be locked and our precommit added
	validatePrecommit(t, cs1, round, round, vss[0], theBlockHash, theBlockHash)

	// we should now be stuck in limbo forever, waiting for more precommits
	// lets add one for a different block
	hash := make([]byte, len(theBlockHash))
	copy(hash, theBlockHash)
	hash[0] = (hash[0] + 1) % 255
	signAddVotes(cs1, types.PrecommitType, hash, thePartSetHeader, vs2)
	ensurePrecommit(voteCh, height, round) // precommit

	// (note we're entering precommit for a second time this round)
	// but with invalid args. then we enterPrecommitWait, and the timeout to new round
	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())

	// -----------

	round++ // moving to the next round
	ensureNewRound(newRoundCh, height, round)
	t.Log("#### ONTO ROUND 1")
	/*
		Round2 (cs1, B) // B B2
	*/

	incrementRound(vs2)

	// now we're on a new round and not the proposer, so wait for timeout
	ensureNewTimeout(timeoutProposeCh, height, round, cs1.config.Propose(round).Nanoseconds())

	// wait to finish prevote
	ensurePrevote(voteCh, height, round)
	rs := cs1.GetRoundState()
	if rs.ProposalBlock != nil {
		panic("Expected proposal block to be nil")
	}

	// we should have prevoted our locked block
	validatePrevote(cs1, round, vss[0], rs.LockedBlock.Hash())

	// add a conflicting prevote from the other validator
	signAddVotes(cs1, types.PrevoteType, hash, rs.LockedBlock.MakePartSet(partSize).Header(), vs2)
	ensurePrevote(voteCh, height, round)

	// now we're going to enter prevote again, but with invalid args
	// and then prevote wait, which should timeout. then wait for precommit
	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Prevote(round).Nanoseconds())

	ensurePrecommit(voteCh, height, round) // precommit
	// the proposed block should still be locked and our precommit added
	// we should precommit nil and be locked on the proposal
	validatePrecommit(t, cs1, round, 0, vss[0], nil, theBlockHash)

	// add conflicting precommit from vs2
	signAddVotes(cs1, types.PrecommitType, hash, rs.LockedBlock.MakePartSet(partSize).Header(), vs2)
	ensurePrecommit(voteCh, height, round)

	// (note we're entering precommit for a second time this round, but with invalid args
	// then we enterPrecommitWait and timeout into NewRound
	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())

	round++ // entering new round
	ensureNewRound(newRoundCh, height, round)
	t.Log("#### ONTO ROUND 2")
	/*
		Round3 (vs2, _) // B, B2
	*/

	incrementRound(vs2)
	ensureNewProposal(proposalCh, height, round)
	ensurePrevote(voteCh, height, round) // prevote
	rs = cs1.GetRoundState()

	// now we're on a new round and are the proposer
	if !bytes.Equal(rs.ProposalBlock.Hash(), rs.LockedBlock.Hash()) {
		panic(fmt.Sprintf("Expected proposal block to be locked block. Got %v, Expected %v", rs.ProposalBlock, rs.LockedBlock))
	}

	validatePrevote(cs1, round, vss[0], rs.LockedBlock.Hash())
	signAddVotes(cs1, types.PrevoteType, hash, rs.ProposalBlock.MakePartSet(partSize).Header(), vs2)
	ensurePrevote(voteCh, height, round)

	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Prevote(round).Nanoseconds())
	ensurePrecommit(voteCh, height, round) // precommit

	validatePrecommit(t, cs1, round, 0, vss[0], nil, theBlockHash) // precommit nil but be locked on proposal

	signAddVotes(cs1, types.PrecommitType, hash, rs.ProposalBlock.MakePartSet(partSize).Header(), vs2) // NOTE: conflicting precommits at same height
	ensurePrecommit(voteCh, height, round)

	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())

	cs2, _ := randConsensusState(2) // needed so generated block is different than locked block
	// before we time out into new round, set next proposal block
	prop, propBlock := decideProposal(cs2, vs2, vs2.Height, vs2.Round+1)
	if prop == nil || propBlock == nil {
		t.Fatal("Failed to create proposal block with vs2")
	}

	incrementRound(vs2)

	round++ // entering new round
	ensureNewRound(newRoundCh, height, round)
	t.Log("#### ONTO ROUND 3")
	/*
		Round4 (vs2, C) // B C // B C
	*/

	// now we're on a new round and not the proposer
	// so set the proposal block
	if err := cs1.SetProposalAndBlock(prop, propBlock, propBlock.MakePartSet(partSize), ""); err != nil {
		t.Fatal(err)
	}

	ensureNewProposal(proposalCh, height, round)
	ensurePrevote(voteCh, height, round) // prevote
	// prevote for locked block (not proposal)
	validatePrevote(cs1, 3, vss[0], cs1.LockedBlock.Hash())

	// prevote for proposed block
	signAddVotes(cs1, types.PrevoteType, propBlock.Hash(), propBlock.MakePartSet(partSize).Header(), vs2)
	ensurePrevote(voteCh, height, round)

	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Prevote(round).Nanoseconds())
	ensurePrecommit(voteCh, height, round)
	validatePrecommit(t, cs1, round, 0, vss[0], nil, theBlockHash) // precommit nil but locked on proposal

	signAddVotes(cs1, types.PrecommitType, propBlock.Hash(), propBlock.MakePartSet(partSize).Header(), vs2) // NOTE: conflicting precommits at same height
	ensurePrecommit(voteCh, height, round)

	cs1.Stop()
	cs1.Wait()
}

// 4 vals, one precommits, other 3 polka at next round, so we unlock and precomit the polka
func TestStateLockPOLRelock(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, cs1.Round

	partSize := types.BlockPartSizeBytes

	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutWait{})
	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})
	addr := cs1.privValidator.GetPubKey().Address()
	voteCh := subscribeToVoter(cs1, addr)
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	newBlockCh := subscribe(cs1.evsw, types.EventNewBlockHeader{})

	// everything done from perspective of cs1

	/*
		Round1 (cs1, B) // B B B B // B nil B nil

		eg. vs2 and vs4 didn't see the 2/3 prevotes
	*/

	// start round and wait for propose and prevote
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, proposalCh, timeoutWaitCh, newRoundCh, newBlockCh, voteCh)

	ensureNewRound(newRoundCh, height, round)
	ensureNewProposal(proposalCh, height, round)
	ensurePrevote(voteCh, height, round) // prevote
	rs := cs1.GetRoundState()
	theBlockHash := rs.ProposalBlock.Hash()
	theBlockParts := rs.ProposalBlockParts.Header()

	validatePrevote(cs1, round, vss[0], theBlockHash)

	signAddVotes(cs1, types.PrevoteType, theBlockHash, theBlockParts, vs2, vs3, vs4)

	ensurePrecommit(voteCh, height, round) // our precommit
	// the proposed block should now be locked and our precommit added
	validatePrecommit(t, cs1, round, round, vss[0], theBlockHash, theBlockHash)

	// add precommits from the rest
	signAddVotes(cs1, types.PrecommitType, nil, types.PartSetHeader{}, vs2, vs4)
	signAddVotes(cs1, types.PrecommitType, theBlockHash, theBlockParts, vs3)

	// before we time out, create new proposal from cs1
	prop, propBlock := decideProposal(cs1, vs2, vs2.Height, vs2.Round+1)
	propBlockParts := propBlock.MakePartSet(partSize)
	propBlockHash := propBlock.Hash()

	// timeout to new round
	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())

	// after new round, cs1 sees the new proposal.
	if err := cs1.SetProposalAndBlock(prop, propBlock, propBlockParts, "some peer"); err != nil {
		t.Fatal(err)
	}

	incrementRound(vs2, vs3, vs4)

	round++                                   // moving to the next round
	ensureNewRound(newRoundCh, height, round) // XXX but the state machine is stuck on this
	// Really, we want to kinda do both... but i guedd
	t.Log("### ONTO ROUND 1")

	/*
		Round2 (vs2, C) // B C C C // C C C _)

		cs1 changes lock!
	*/

	// now we're on a new round and not the proposer
	// but we should receive the proposal
	ensureNewProposal(proposalCh, height, round)

	// go to prevote, prevote for locked block (not proposal), move on
	ensurePrevote(voteCh, height, round)
	validatePrevote(cs1, round, vss[0], theBlockHash)

	// now lets add prevotes from everyone else for the new block
	signAddVotes(cs1, types.PrevoteType, propBlockHash, propBlockParts.Header(), vs2, vs3, vs4)

	ensurePrecommit(voteCh, height, round)
	// we should have unlocked and locked on the new block
	validatePrecommit(t, cs1, round, round, vss[0], propBlockHash, propBlockHash)

	signAddVotes(cs1, types.PrecommitType, propBlockHash, propBlockParts.Header(), vs2, vs3)
	ensureNewBlockHeader(newBlockCh, height, propBlockHash)

	ensureNewRound(newRoundCh, height+1, 0)
}

// 4 vals, one precommits, other 3 polka at next round, so we unlock and precomit the polka
func TestStateLockPOLUnlock(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, cs1.Round

	partSize := types.BlockPartSizeBytes

	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})
	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutWait{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	unlockCh := subscribe(cs1.evsw, cstypes.EventUnlock{})
	addr := cs1.privValidator.GetPubKey().Address()
	voteCh := subscribeToVoter(cs1, addr)

	// everything done from perspective of cs1

	/*
		Round1 (cs1, B) // B B B B // B nil B nil

		eg. didn't see the 2/3 prevotes
	*/

	// start round and wait for propose and prevote
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, proposalCh, timeoutWaitCh, newRoundCh, voteCh, unlockCh)

	ensureNewRound(newRoundCh, height, round)
	ensureNewProposal(proposalCh, height, round)
	ensurePrevote(voteCh, height, round)
	rs := cs1.GetRoundState()
	theBlockHash := rs.ProposalBlock.Hash()
	theBlockParts := rs.ProposalBlockParts.Header()

	validatePrevote(cs1, round, vss[0], theBlockHash)

	signAddVotes(cs1, types.PrevoteType, theBlockHash, theBlockParts, vs2, vs3, vs4)

	ensurePrecommit(voteCh, height, round)
	// the proposed block should now be locked and our precommit added
	validatePrecommit(t, cs1, round, round, vss[0], theBlockHash, theBlockHash)

	// add precommits from the rest
	signAddVotes(cs1, types.PrecommitType, nil, types.PartSetHeader{}, vs2, vs4)
	signAddVotes(cs1, types.PrecommitType, theBlockHash, theBlockParts, vs3)

	// before we time out into new round, set next proposal block
	prop, propBlock := decideProposal(cs1, vs2, vs2.Height, vs2.Round+1)
	propBlockParts := propBlock.MakePartSet(partSize)
	// propBlockHash := propBlock.Hash()

	// timeout to new round
	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())
	// TODO check this assertion directly.
	lockedBlockHash := cs1.LockedBlock.Hash() // avoid mutex on cs1.

	// after new round, cs1 sees the new proposal.
	if err := cs1.SetProposalAndBlock(prop, propBlock, propBlockParts, "some peer"); err != nil {
		t.Fatal(err)
	}

	incrementRound(vs2, vs3, vs4)
	round++ // moving to the next round

	ensureNewRound(newRoundCh, height, round)
	t.Log("#### ONTO ROUND 1")
	/*
		Round2 (vs2, C) // B nil nil nil // nil nil nil _

		cs1 unlocks!
	*/

	ensureNewProposal(proposalCh, height, round)

	// go to prevote, prevote for locked block (not proposal)
	ensurePrevote(voteCh, height, round)
	validatePrevote(cs1, round, vss[0], lockedBlockHash)
	// now lets add prevotes from everyone else for nil (a polka!)
	signAddVotes(cs1, types.PrevoteType, nil, types.PartSetHeader{}, vs2, vs3, vs4)

	// the polka makes us unlock and precommit nil
	ensureNewUnlock(unlockCh, height, round)
	ensurePrecommit(voteCh, height, round)

	// we should have unlocked and committed nil
	// NOTE: since we don't relock on nil, the lock round is -1
	validatePrecommit(t, cs1, round, -1, vss[0], nil, nil)

	signAddVotes(cs1, types.PrecommitType, nil, types.PartSetHeader{}, vs2, vs3)

	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())
	ensureNewRound(newRoundCh, height, round+1)
}

// 4 vals
// a polka at round 1 but we miss it
// then a polka at round 2 that we lock on
// then we see the polka from round 1 but shouldn't unlock
func TestStateLockPOLSafety1(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, cs1.Round

	partSize := types.BlockPartSizeBytes

	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})
	timeoutProposeCh := subscribe(cs1.evsw, cstypes.EventTimeoutPropose{})
	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutWait{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	addr := cs1.privValidator.GetPubKey().Address()
	voteCh := subscribeToVoter(cs1, addr)

	// start round and wait for propose and prevote
	startFrom(cs1, cs1.Height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, proposalCh, timeoutWaitCh, timeoutProposeCh, newRoundCh, voteCh)

	ensureNewRound(newRoundCh, height, round)
	ensureNewProposal(proposalCh, height, round)
	ensurePrevote(voteCh, height, round)
	rs := cs1.GetRoundState()
	propBlock := rs.ProposalBlock

	validatePrevote(cs1, round, vss[0], propBlock.Hash())

	// the others sign a polka but we don't see it
	prevotes := signVotes(types.PrevoteType, propBlock.Hash(), propBlock.MakePartSet(partSize).Header(), vs2, vs3, vs4)

	t.Logf("old prop hash %v", fmt.Sprintf("%X", propBlock.Hash()))

	// we do see them precommit nil
	signAddVotes(cs1, types.PrecommitType, nil, types.PartSetHeader{}, vs2, vs3, vs4)

	// cs1 precommit nil
	ensurePrecommit(voteCh, height, round)
	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())

	t.Log("### ONTO ROUND 1")

	prop, propBlock := decideProposal(cs1, vs2, vs2.Height, vs2.Round+1)
	propBlockHash := propBlock.Hash()
	propBlockParts := propBlock.MakePartSet(partSize)

	incrementRound(vs2, vs3, vs4)

	round++ // moving to the next round
	ensureNewRound(newRoundCh, height, round)

	// XXX: this isnt guaranteed to get there before the timeoutPropose ...
	if err := cs1.SetProposalAndBlock(prop, propBlock, propBlockParts, "some peer"); err != nil {
		t.Fatal(err)
	}
	/*Round2
	// we timeout and prevote our lock
	// a polka happened but we didn't see it!
	*/

	// go to prevote, prevote for proposal block
	ensureNewProposal(proposalCh, height, round)
	ensurePrevote(voteCh, height, round)
	rs = cs1.GetRoundState()
	if rs.LockedBlock != nil {
		panic("we should not be locked!")
	}
	t.Logf("new prop hash %v", fmt.Sprintf("%X", propBlockHash))

	validatePrevote(cs1, round, vss[0], propBlockHash)

	// now we see the others prevote for it, so we should lock on it
	signAddVotes(cs1, types.PrevoteType, propBlockHash, propBlockParts.Header(), vs2, vs3, vs4)

	ensurePrecommit(voteCh, height, round)
	// we should have precommitted
	validatePrecommit(t, cs1, round, round, vss[0], propBlockHash, propBlockHash)

	signAddVotes(cs1, types.PrecommitType, nil, types.PartSetHeader{}, vs2, vs3, vs4)

	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())

	incrementRound(vs2, vs3, vs4)
	round++ // moving to the next round

	ensureNewRound(newRoundCh, height, round)

	t.Log("### ONTO ROUND 2")
	/*Round3
	we see the polka from round 1 but we shouldn't unlock!
	*/

	// timeout of propose
	ensureNewTimeout(timeoutProposeCh, height, round, cs1.config.Propose(round).Nanoseconds())

	// finish prevote
	ensurePrevote(voteCh, height, round)
	// we should prevote what we're locked on
	validatePrevote(cs1, round, vss[0], propBlockHash)

	newStepCh := subscribe(cs1.evsw, cstypes.EventNewRoundStep{})
	defer ensureDrainedChannels(t, newStepCh)

	// before prevotes from the previous round are added
	// add prevotes from the earlier round
	addVotes(cs1, prevotes...)

	t.Log("Done adding prevotes!")

	ensureNoNewRoundStep(newStepCh)
}

// 4 vals.
// polka P0 at R0, P1 at R1, and P2 at R2,
// we lock on P0 at R0, don't see P1, and unlock using P2 at R2
// then we should make sure we don't lock using P1

// What we want:
// dont see P0, lock on P1 at R1, dont unlock using P0 at R2
func TestStateLockPOLSafety2(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, cs1.Round

	partSize := types.BlockPartSizeBytes

	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})
	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutWait{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	unlockCh := subscribe(cs1.evsw, cstypes.EventUnlock{})
	addr := cs1.privValidator.GetPubKey().Address()
	voteCh := subscribeToVoter(cs1, addr)

	// the block for R0: gets polkad but we miss it
	// (even though we signed it, shhh)
	_, propBlock0 := decideProposal(cs1, vss[0], height, round)
	propBlockHash0 := propBlock0.Hash()
	propBlockParts0 := propBlock0.MakePartSet(partSize)
	propBlockID0 := types.BlockID{Hash: propBlockHash0, PartsHeader: propBlockParts0.Header()}

	// the others sign a polka but we don't see it
	prevotes := signVotes(types.PrevoteType, propBlockHash0, propBlockParts0.Header(), vs2, vs3, vs4)

	// the block for round 1
	prop1, propBlock1 := decideProposal(cs1, vs2, vs2.Height, vs2.Round+1)
	propBlockHash1 := propBlock1.Hash()
	propBlockParts1 := propBlock1.MakePartSet(partSize)

	incrementRound(vs2, vs3, vs4)

	round++ // moving to the next round
	t.Log("### ONTO Round 1")
	// jump in at round 1
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, proposalCh, timeoutWaitCh, newRoundCh, unlockCh, voteCh)

	ensureNewRound(newRoundCh, height, round)
	if err := cs1.SetProposalAndBlock(prop1, propBlock1, propBlockParts1, "some peer"); err != nil {
		t.Fatal(err)
	}
	ensureNewProposal(proposalCh, height, round)

	ensurePrevote(voteCh, height, round)
	validatePrevote(cs1, round, vss[0], propBlockHash1)

	signAddVotes(cs1, types.PrevoteType, propBlockHash1, propBlockParts1.Header(), vs2, vs3, vs4)

	ensurePrecommit(voteCh, height, round)
	// the proposed block should now be locked and our precommit added
	validatePrecommit(t, cs1, round, round, vss[0], propBlockHash1, propBlockHash1)

	// add precommits from the rest
	signAddVotes(cs1, types.PrecommitType, nil, types.PartSetHeader{}, vs2, vs4)
	signAddVotes(cs1, types.PrecommitType, propBlockHash1, propBlockParts1.Header(), vs3)

	incrementRound(vs2, vs3, vs4)

	// timeout of precommit wait to new round
	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())

	round++ // moving to the next round
	// in round 2 we see the polkad block from round 0
	newProp := types.NewProposal(height, round, 0, propBlockID0)
	if err := vs3.SignProposal(config.ChainID(), newProp); err != nil {
		t.Fatal(err)
	}
	if err := cs1.SetProposalAndBlock(newProp, propBlock0, propBlockParts0, "some peer"); err != nil {
		t.Fatal(err)
	}

	// Add the pol votes
	addVotes(cs1, prevotes...)

	ensureNewRound(newRoundCh, height, round)
	t.Log("### ONTO Round 2")
	/*Round2
	// now we see the polka from round 1, but we shouldn't unlock
	*/
	ensureNewProposal(proposalCh, height, round)

	ensureNoNewUnlock(unlockCh)
	ensurePrevote(voteCh, height, round)
	validatePrevote(cs1, round, vss[0], propBlockHash1)
}

// 4 vals.
// polka P0 at R0 for B0. We lock B0 on P0 at R0. P0 unlocks value at R1.
// After unlocking, we should propose the last valid block.

// What we want:
// P0 proposes B0 at R3.
func TestProposeValidBlock(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, cs1.Round

	partSize := types.BlockPartSizeBytes

	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})
	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutWait{})
	timeoutProposeCh := subscribe(cs1.evsw, cstypes.EventTimeoutPropose{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	unlockCh := subscribe(cs1.evsw, cstypes.EventUnlock{})
	addr := cs1.privValidator.GetPubKey().Address()
	voteCh := subscribeToVoter(cs1, addr)

	// start round and wait for propose and prevote
	startFrom(cs1, cs1.Height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()

	defer ensureDrainedChannels(t, proposalCh, timeoutWaitCh, timeoutProposeCh, newRoundCh, unlockCh, voteCh)

	ensureNewRound(newRoundCh, height, round)
	ensureNewProposal(proposalCh, height, round)
	ensurePrevote(voteCh, height, round)
	rs := cs1.GetRoundState()
	propBlock := rs.ProposalBlock
	propBlockHash := propBlock.Hash()

	validatePrevote(cs1, round, vss[0], propBlockHash)

	// the others sign a polka
	signAddVotes(cs1, types.PrevoteType, propBlockHash, propBlock.MakePartSet(partSize).Header(), vs2, vs3, vs4)

	ensurePrecommit(voteCh, height, round)
	// we should have precommitted
	validatePrecommit(t, cs1, round, round, vss[0], propBlockHash, propBlockHash)

	signAddVotes(cs1, types.PrecommitType, nil, types.PartSetHeader{}, vs2, vs3, vs4)

	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())

	incrementRound(vs2, vs3, vs4)
	round++ // moving to the next round

	ensureNewRound(newRoundCh, height, round)

	t.Log("### ONTO ROUND 2")

	// timeout of propose
	ensureNewTimeout(timeoutProposeCh, height, round, cs1.config.Propose(round).Nanoseconds())

	ensurePrevote(voteCh, height, round)
	validatePrevote(cs1, round, vss[0], propBlockHash)

	signAddVotes(cs1, types.PrevoteType, nil, types.PartSetHeader{}, vs2, vs3, vs4)

	ensureNewUnlock(unlockCh, height, round)

	ensurePrecommit(voteCh, height, round)
	// we should have precommitted
	validatePrecommit(t, cs1, round, -1, vss[0], nil, nil)

	incrementRound(vs2, vs3, vs4)
	incrementRound(vs2, vs3, vs4)

	signAddVotes(cs1, types.PrecommitType, nil, types.PartSetHeader{}, vs2, vs3, vs4)

	round += 2 // moving to the next round

	ensureNewRound(newRoundCh, height, round)
	t.Log("### ONTO ROUND 3")

	// prevote skipped.
	// ensurePrevote(voteCh, height, round)
	ensurePrecommit(voteCh, height, round)
	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())

	round++ // moving to the next round

	ensureNewRound(newRoundCh, height, round)

	t.Log("### ONTO ROUND 4")

	ensureNewProposal(proposalCh, height, round)
	ensurePrevote(voteCh, height, round)
	rs = cs1.GetRoundState()
	assert.True(t, bytes.Equal(rs.ProposalBlock.Hash(), propBlockHash))
	assert.True(t, bytes.Equal(rs.ProposalBlock.Hash(), rs.ValidBlock.Hash()))
	assert.True(t, rs.Proposal.POLRound == rs.ValidRound)
	assert.True(t, bytes.Equal(rs.Proposal.BlockID.Hash, rs.ValidBlock.Hash()))
}

// What we want:
// P0 miss to lock B but set valid block to B after receiving delayed prevote.
func TestSetValidBlockOnDelayedPrevote(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, cs1.Round

	partSize := types.BlockPartSizeBytes

	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})
	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutWait{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	validBlockCh := subscribe(cs1.evsw, cstypes.EventNewValidBlock{})
	addr := cs1.privValidator.GetPubKey().Address()
	voteCh := subscribeToVoter(cs1, addr)

	// start round and wait for propose and prevote
	startFrom(cs1, cs1.Height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, timeoutWaitCh, newRoundCh, validBlockCh, voteCh, proposalCh)

	ensureNewRound(newRoundCh, height, round)
	ensureNewProposal(proposalCh, height, round)
	ensurePrevote(voteCh, height, round)
	rs := cs1.GetRoundState()
	propBlock := rs.ProposalBlock
	propBlockHash := propBlock.Hash()
	propBlockParts := propBlock.MakePartSet(partSize)

	validatePrevote(cs1, round, vss[0], propBlockHash)

	// vs2 send prevote for propBlock
	signAddVotes(cs1, types.PrevoteType, propBlockHash, propBlockParts.Header(), vs2)

	// vs3 send prevote nil
	signAddVotes(cs1, types.PrevoteType, nil, types.PartSetHeader{}, vs3)

	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Prevote(round).Nanoseconds())

	ensurePrecommit(voteCh, height, round)
	// we should have precommitted
	validatePrecommit(t, cs1, round, -1, vss[0], nil, nil)

	rs = cs1.GetRoundState()

	assert.True(t, rs.ValidBlock == nil)
	assert.True(t, rs.ValidBlockParts == nil)
	assert.True(t, rs.ValidRound == -1)

	// vs2 send (delayed) prevote for propBlock
	signAddVotes(cs1, types.PrevoteType, propBlockHash, propBlockParts.Header(), vs4)

	ensureNewValidBlock(validBlockCh, height, round)

	rs = cs1.GetRoundState()

	assert.True(t, bytes.Equal(rs.ValidBlock.Hash(), propBlockHash))
	assert.True(t, rs.ValidBlockParts.Header().Equals(propBlockParts.Header()))
	assert.True(t, rs.ValidRound == round)
}

// What we want:
// P0 miss to lock B as Proposal Block is missing, but set valid block to B after
// receiving delayed Block Proposal.
func TestSetValidBlockOnDelayedProposal(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, cs1.Round

	partSize := types.BlockPartSizeBytes

	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutWait{})
	timeoutProposeCh := subscribe(cs1.evsw, cstypes.EventTimeoutPropose{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	validBlockCh := subscribe(cs1.evsw, cstypes.EventNewValidBlock{})
	addr := cs1.privValidator.GetPubKey().Address()
	voteCh := subscribeToVoter(cs1, addr)
	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})

	round++ // move to round in which P0 is not proposer
	incrementRound(vs2, vs3, vs4)

	startFrom(cs1, cs1.Height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, timeoutWaitCh, timeoutProposeCh, newRoundCh, validBlockCh, voteCh, proposalCh)

	ensureNewRound(newRoundCh, height, round)
	ensureNewTimeout(timeoutProposeCh, height, round, cs1.config.Propose(round).Nanoseconds())

	ensurePrevote(voteCh, height, round)
	validatePrevote(cs1, round, vss[0], nil)

	prop, propBlock := decideProposal(cs1, vs2, vs2.Height, vs2.Round+1)
	propBlockHash := propBlock.Hash()
	propBlockParts := propBlock.MakePartSet(partSize)

	// vs2, vs3 and vs4 send prevote for propBlock
	signAddVotes(cs1, types.PrevoteType, propBlockHash, propBlockParts.Header(), vs2, vs3, vs4)
	ensureNewValidBlock(validBlockCh, height, round)

	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Prevote(round).Nanoseconds())

	ensurePrecommit(voteCh, height, round)
	validatePrecommit(t, cs1, round, -1, vss[0], nil, nil)

	if err := cs1.SetProposalAndBlock(prop, propBlock, propBlockParts, "some peer"); err != nil {
		t.Fatal(err)
	}

	ensureNewProposal(proposalCh, height, round)
	rs := cs1.GetRoundState()

	assert.True(t, bytes.Equal(rs.ValidBlock.Hash(), propBlockHash))
	assert.True(t, rs.ValidBlockParts.Header().Equals(propBlockParts.Header()))
	assert.True(t, rs.ValidRound == round)
}

// 4 vals, 3 Nil Precommits at P0
// What we want:
// P0 waits for timeoutPrecommit before starting next round
func TestWaitingTimeoutOnNilPolka(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, cs1.Round

	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutWait{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})

	// start round
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, timeoutWaitCh, newRoundCh)

	ensureNewRound(newRoundCh, height, round)
	signAddVotes(cs1, types.PrecommitType, nil, types.PartSetHeader{}, vs2, vs3, vs4)

	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())
	ensureNewRound(newRoundCh, height, round+1)
}

// 4 vals, 3 Prevotes for nil from the higher round.
// What we want:
// P0 waits for timeoutPropose in the next round before entering prevote
func TestWaitingTimeoutProposeOnNewRound(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, cs1.Round

	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutPropose{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	addr := cs1.privValidator.GetPubKey().Address()
	voteCh := subscribeToVoter(cs1, addr)

	// start round
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, timeoutWaitCh, newRoundCh, voteCh)

	ensureNewRound(newRoundCh, height, round)
	ensurePrevote(voteCh, height, round)

	incrementRound(vss[1:]...)
	signAddVotes(cs1, types.PrevoteType, nil, types.PartSetHeader{}, vs2, vs3, vs4)

	round++ // moving to the next round
	ensureNewRound(newRoundCh, height, round)

	rs := cs1.GetRoundState()
	assert.True(t, rs.Step == cstypes.RoundStepPropose) // P0 does not prevote before timeoutPropose expires

	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Propose(round).Nanoseconds())

	ensurePrevote(voteCh, height, round)
	validatePrevote(cs1, round, vss[0], nil)
}

// 4 vals, 3 Precommits for nil from the higher round.
// What we want:
// P0 jump to higher round, precommit and start precommit wait
func TestRoundSkipOnNilPolkaFromHigherRound(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, cs1.Round

	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutWait{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	addr := cs1.privValidator.GetPubKey().Address()
	voteCh := subscribeToVoter(cs1, addr)

	// start round
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, timeoutWaitCh, newRoundCh, voteCh)

	ensureNewRound(newRoundCh, height, round)
	ensurePrevote(voteCh, height, round)

	incrementRound(vss[1:]...)
	signAddVotes(cs1, types.PrecommitType, nil, types.PartSetHeader{}, vs2, vs3, vs4)

	round++ // moving to the next round
	ensureNewRound(newRoundCh, height, round)

	ensurePrecommit(voteCh, height, round)
	validatePrecommit(t, cs1, round, -1, vss[0], nil, nil)

	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())

	round++ // moving to the next round
	ensureNewRound(newRoundCh, height, round)
}

// 4 vals, 3 Prevotes for nil in the current round.
// What we want:
// P0 wait for timeoutPropose to expire before sending prevote.
func TestWaitTimeoutProposeOnNilPolkaForTheCurrentRound(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, 1

	timeoutProposeCh := subscribe(cs1.evsw, cstypes.EventTimeoutPropose{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	addr := cs1.privValidator.GetPubKey().Address()
	voteCh := subscribeToVoter(cs1, addr)

	// start round in which PO is not proposer
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, timeoutProposeCh, newRoundCh, voteCh)

	ensureNewRound(newRoundCh, height, round)
	incrementRound(vss[1:]...)
	signAddVotes(cs1, types.PrevoteType, nil, types.PartSetHeader{}, vs2, vs3, vs4)

	ensureNewTimeout(timeoutProposeCh, height, round, cs1.config.Propose(round).Nanoseconds())

	ensurePrevote(voteCh, height, round)
	validatePrevote(cs1, round, vss[0], nil)
}

// What we want:
// P0 emit NewValidBlock event upon receiving 2/3+ Precommit for B but hasn't received block B yet
func TestEmitNewValidBlockEventOnCommitWithoutBlock(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, 1

	incrementRound(vs2, vs3, vs4)

	partSize := types.BlockPartSizeBytes

	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	validBlockCh := subscribe(cs1.evsw, cstypes.EventNewValidBlock{})

	_, propBlock := decideProposal(cs1, vs2, vs2.Height, vs2.Round)
	propBlockHash := propBlock.Hash()
	propBlockParts := propBlock.MakePartSet(partSize)

	// start round in which PO is not proposer
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, newRoundCh, newRoundCh, validBlockCh)

	ensureNewRound(newRoundCh, height, round)
	// vs2, vs3 and vs4 send precommit for propBlock
	signAddVotes(cs1, types.PrecommitType, propBlockHash, propBlockParts.Header(), vs2, vs3, vs4)
	ensureNewValidBlock(validBlockCh, height, round)

	rs := cs1.GetRoundState()
	assert.True(t, rs.Step == cstypes.RoundStepCommit)
	assert.True(t, rs.ProposalBlock == nil)
	assert.True(t, rs.ProposalBlockParts.Header().Equals(propBlockParts.Header()))
}

// What we want:
// P0 receives 2/3+ Precommit for B for round 0, while being in round 1. It emits NewValidBlock event.
// After receiving block, it executes block and moves to the next height.
func TestCommitFromPreviousRound(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, 1

	partSize := types.BlockPartSizeBytes

	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	validBlockCh := subscribe(cs1.evsw, cstypes.EventNewValidBlock{})
	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})

	prop, propBlock := decideProposal(cs1, vs2, vs2.Height, vs2.Round)
	propBlockHash := propBlock.Hash()
	propBlockParts := propBlock.MakePartSet(partSize)

	// start round in which PO is not proposer
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, proposalCh, newRoundCh, validBlockCh)

	ensureNewRound(newRoundCh, height, round)
	// vs2, vs3 and vs4 send precommit for propBlock for the previous round
	signAddVotes(cs1, types.PrecommitType, propBlockHash, propBlockParts.Header(), vs2, vs3, vs4)

	ensureNewValidBlock(validBlockCh, height, round)

	rs := cs1.GetRoundState()
	assert.True(t, rs.Step == cstypes.RoundStepCommit)
	assert.True(t, rs.CommitRound == vs2.Round)
	assert.True(t, rs.ProposalBlock == nil)
	assert.True(t, rs.ProposalBlockParts.Header().Equals(propBlockParts.Header()))

	if err := cs1.SetProposalAndBlock(prop, propBlock, propBlockParts, "some peer"); err != nil {
		t.Fatal(err)
	}

	ensureNewProposal(proposalCh, height, round)
	ensureNewRound(newRoundCh, height+1, 0)
}

type fakeTxNotifier struct {
	ch chan struct{}
}

func (n *fakeTxNotifier) TxsAvailable() <-chan struct{} {
	return n.ch
}

func (n *fakeTxNotifier) Notify() {
	n.ch <- struct{}{}
}

func TestStartNextHeightCorrectly(t *testing.T) {
	config.Consensus.SkipTimeoutCommit = false
	cs1, vss := randConsensusState(4)
	cs1.txNotifier = &fakeTxNotifier{ch: make(chan struct{})}

	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, cs1.Round

	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})
	timeoutProposeCh := subscribe(cs1.evsw, cstypes.EventTimeoutPropose{})

	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	newBlockHeader := subscribe(cs1.evsw, types.EventNewBlockHeader{})
	addr := cs1.privValidator.GetPubKey().Address()
	voteCh := subscribeToVoter(cs1, addr)

	// start round and wait for propose and prevote
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, proposalCh, newRoundCh, voteCh, newBlockHeader)

	ensureNewRound(newRoundCh, height, round)
	ensureNewProposal(proposalCh, height, round)
	ensurePrevote(voteCh, height, round)
	rs := cs1.GetRoundState()
	theBlockHash := rs.ProposalBlock.Hash()
	theBlockParts := rs.ProposalBlockParts.Header()

	validatePrevote(cs1, round, vss[0], theBlockHash)

	signAddVotes(cs1, types.PrevoteType, theBlockHash, theBlockParts, vs2, vs3, vs4)

	ensurePrecommit(voteCh, height, round)
	// the proposed block should now be locked and our precommit added
	validatePrecommit(t, cs1, round, round, vss[0], theBlockHash, theBlockHash)

	// add precommits
	signAddVotes(cs1, types.PrecommitType, nil, types.PartSetHeader{}, vs2)
	signAddVotes(cs1, types.PrecommitType, theBlockHash, theBlockParts, vs3)
	time.Sleep(5 * time.Millisecond)
	signAddVotes(cs1, types.PrecommitType, theBlockHash, theBlockParts, vs4)

	rs = cs1.GetRoundState()
	assert.True(t, rs.TriggeredTimeoutPrecommit)

	ensureNewBlockHeader(newBlockHeader, height, theBlockHash)

	go cs1.txNotifier.(*fakeTxNotifier).Notify()

	height, round = height+1, 0
	ensureNewRound(newRoundCh, height, round)
	ensureNewTimeout(timeoutProposeCh, height, round, cs1.config.Propose(round).Nanoseconds())
	ensurePrevote(voteCh, height, round)
	rs = cs1.GetRoundState()
	assert.False(t, rs.TriggeredTimeoutPrecommit, "triggeredTimeoutPrecommit should be false at the beginning of each round")
}

func TestFlappyResetTimeoutPrecommitUponNewHeight(t *testing.T) {
	t.Parallel()

	testutils.FilterStability(t, testutils.Flappy)

	config.Consensus.SkipTimeoutCommit = false
	cs1, vss := randConsensusState(4)

	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, cs1.Round

	partSize := types.BlockPartSizeBytes

	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	newBlockHeader := subscribe(cs1.evsw, types.EventNewBlockHeader{})
	addr := cs1.privValidator.GetPubKey().Address()
	voteCh := subscribeToVoter(cs1, addr)

	// start round and wait for propose and prevote
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, proposalCh, newRoundCh, voteCh, newBlockHeader)

	ensureNewRound(newRoundCh, height, round)
	ensureNewProposal(proposalCh, height, round)
	rs := cs1.GetRoundState()
	theBlockHash := rs.ProposalBlock.Hash()
	theBlockParts := rs.ProposalBlockParts.Header()

	ensurePrevote(voteCh, height, round)
	validatePrevote(cs1, round, vss[0], theBlockHash)

	signAddVotes(cs1, types.PrevoteType, theBlockHash, theBlockParts, vs2, vs3, vs4)

	ensurePrecommit(voteCh, height, round)
	validatePrecommit(t, cs1, round, round, vss[0], theBlockHash, theBlockHash)

	// add precommits
	signAddVotes(cs1, types.PrecommitType, nil, types.PartSetHeader{}, vs2)
	signAddVotes(cs1, types.PrecommitType, theBlockHash, theBlockParts, vs3)
	signAddVotes(cs1, types.PrecommitType, theBlockHash, theBlockParts, vs4)

	ensureNewBlockHeader(newBlockHeader, height, theBlockHash)

	prop, propBlock := decideProposal(cs1, vs2, height+1, 0)
	propBlockParts := propBlock.MakePartSet(partSize)

	if err := cs1.SetProposalAndBlock(prop, propBlock, propBlockParts, "some peer"); err != nil {
		t.Fatal(err)
	}
	ensureNewRound(newRoundCh, height+1, 0)
	ensureNewProposal(proposalCh, height+1, 0)

	rs = cs1.GetRoundState()
	assert.False(t, rs.TriggeredTimeoutPrecommit, "triggeredTimeoutPrecommit should be false at the beginning of each height")
}

// ------------------------------------------------------------------------------------------
// SlashingSuite
// TODO: Slashing

/*
func TestStateSlashingPrevotes(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(2)
	vs2 := vss[1]


	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})
	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutWait{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	voteCh := subscribeToVoter(cs1, cs1.privValidator.GetAddress())

	// start round and wait for propose and prevote
	startFrom(cs1, cs1.Height, 0)
	<-newRoundCh
	re := <-proposalCh
	<-voteCh // prevote

	rs := re.(types.EventDataRoundState).RoundState.(*cstypes.RoundState)

	// we should now be stuck in limbo forever, waiting for more prevotes
	// add one for a different block should cause us to go into prevote wait
	hash := rs.ProposalBlock.Hash()
	hash[0] = byte(hash[0]+1) % 255
	signAddVotes(cs1, types.PrevoteType, hash, rs.ProposalBlockParts.Header(), vs2)

	<-timeoutWaitCh

	// NOTE: we have to send the vote for different block first so we don't just go into precommit round right
	// away and ignore more prevotes (and thus fail to slash!)

	// add the conflicting vote
	signAddVotes(cs1, types.PrevoteType, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(), vs2)

	// XXX: Check for existence of Dupeout info
}

func TestStateSlashingPrecommits(t *testing.T) {
	t.Parallel()

	cs1, vss := randConsensusState(2)
	vs2 := vss[1]


	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})
	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutWait{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	voteCh := subscribeToVoter(cs1, cs1.privValidator.GetAddress())

	// start round and wait for propose and prevote
	startFrom(cs1, cs1.Height, 0)
	<-newRoundCh
	re := <-proposalCh
	<-voteCh // prevote

	// add prevote from vs2
	signAddVotes(cs1, types.PrevoteType, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(), vs2)

	<-voteCh // precommit

	// we should now be stuck in limbo forever, waiting for more prevotes
	// add one for a different block should cause us to go into prevote wait
	hash := rs.ProposalBlock.Hash()
	hash[0] = byte(hash[0]+1) % 255
	signAddVotes(cs1, types.PrecommitType, hash, rs.ProposalBlockParts.Header(), vs2)

	// NOTE: we have to send the vote for different block first so we don't just go into precommit round right
	// away and ignore more prevotes (and thus fail to slash!)

	// add precommit from vs2
	signAddVotes(cs1, types.PrecommitType, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(), vs2)

	// XXX: Check for existence of Dupeout info
}
*/

// ------------------------------------------------------------------------------------------
// CatchupSuite

// ------------------------------------------------------------------------------------------
// HaltSuite

// 4 vals.
// we receive a final precommit after going into next round, but others might have gone to commit already!
func TestFlappyStateHalt1(t *testing.T) {
	t.Parallel()

	testutils.FilterStability(t, testutils.Flappy)
	cs1, vss := randConsensusState(4)
	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
	height, round := cs1.Height, cs1.Round
	partSize := types.BlockPartSizeBytes

	proposalCh := subscribe(cs1.evsw, cstypes.EventCompleteProposal{})
	timeoutWaitCh := subscribe(cs1.evsw, cstypes.EventTimeoutWait{})
	newRoundCh := subscribe(cs1.evsw, cstypes.EventNewRound{})
	newBlockCh := subscribe(cs1.evsw, types.EventNewBlock{})
	addr := cs1.privValidator.GetPubKey().Address()
	voteCh := subscribeToVoter(cs1, addr)

	// start round and wait for propose and prevote
	startFrom(cs1, height, round)
	defer func() {
		cs1.Stop()
		cs1.Wait()
	}()
	defer ensureDrainedChannels(t, proposalCh, timeoutWaitCh, newRoundCh, voteCh, newBlockCh)

	ensureNewRound(newRoundCh, height, round)
	ensureNewProposal(proposalCh, height, round)
	rs := cs1.GetRoundState()
	propBlock := rs.ProposalBlock
	propBlockParts := propBlock.MakePartSet(partSize)

	ensurePrevote(voteCh, height, round)

	signAddVotes(cs1, types.PrevoteType, propBlock.Hash(), propBlockParts.Header(), vs2, vs3, vs4)

	ensurePrecommit(voteCh, height, round)
	// the proposed block should now be locked and our precommit added
	validatePrecommit(t, cs1, round, round, vss[0], propBlock.Hash(), propBlock.Hash())

	// add precommits from the rest
	signAddVotes(cs1, types.PrecommitType, nil, types.PartSetHeader{}, vs2) // didnt receive proposal
	signAddVotes(cs1, types.PrecommitType, propBlock.Hash(), propBlockParts.Header(), vs3)
	// we receive this later, but vs3 might receive it earlier and with ours will go to commit!
	precommit4 := signVote(vs4, types.PrecommitType, propBlock.Hash(), propBlockParts.Header())

	incrementRound(vs2, vs3, vs4)

	// timeout to new round
	ensureNewTimeout(timeoutWaitCh, height, round, cs1.config.Precommit(round).Nanoseconds())

	round++ // moving to the next round

	ensureNewRound(newRoundCh, height, round)
	rs = cs1.GetRoundState()

	t.Log("### ONTO ROUND 1")
	/*Round2
	// we timeout and prevote our lock
	// a polka happened but we didn't see it!
	*/

	// go to prevote, prevote for locked block
	ensurePrevote(voteCh, height, round)
	validatePrevote(cs1, round, vss[0], rs.LockedBlock.Hash())

	// now we receive the precommit from the previous round
	addVotes(cs1, precommit4)

	// receiving that precommit should take us straight to commit
	ensureNewBlock(newBlockCh, height)

	ensureNewRound(newRoundCh, height+1, 0)
}

func TestStateOutputsBlockPartsStats(t *testing.T) {
	t.Parallel()

	// create dummy peer
	cs, _ := randConsensusState(1)
	peer := p2pmock.NewPeer(nil)

	// 1) new block part
	parts := types.NewPartSetFromData(random.RandBytes(100), 10)
	msg := &BlockPartMessage{
		Height: 1,
		Round:  0,
		Part:   parts.GetPart(0),
	}

	cs.ProposalBlockParts = types.NewPartSetFromHeader(parts.Header())
	cs.handleMsg(msgInfo{msg, peer.ID()})

	statsMessage := <-cs.statsMsgQueue
	require.Equal(t, msg, statsMessage.Msg, "")
	require.Equal(t, peer.ID(), statsMessage.PeerID, "")

	// sending the same part from different peer
	cs.handleMsg(msgInfo{msg, "peer2"})

	// sending the part with the same height, but different round
	msg.Round = 1
	cs.handleMsg(msgInfo{msg, peer.ID()})

	// sending the part from the smaller height
	msg.Height = 0
	cs.handleMsg(msgInfo{msg, peer.ID()})

	// sending the part from the bigger height
	msg.Height = 3
	cs.handleMsg(msgInfo{msg, peer.ID()})

	select {
	case <-cs.statsMsgQueue:
		t.Errorf("Should not output stats message after receiving the known block part!")
	case <-time.After(50 * time.Millisecond):
	}
}

func TestStateOutputVoteStats(t *testing.T) {
	t.Parallel()

	cs, vss := randConsensusState(2)
	// create dummy peer
	peer := p2pmock.NewPeer(nil)

	vote := signVote(vss[1], types.PrecommitType, []byte("test"), types.PartSetHeader{})

	voteMessage := &VoteMessage{vote}
	cs.handleMsg(msgInfo{voteMessage, peer.ID()})

	statsMessage := <-cs.statsMsgQueue
	require.Equal(t, voteMessage, statsMessage.Msg, "")
	require.Equal(t, peer.ID(), statsMessage.PeerID, "")

	// sending the same part from different peer
	cs.handleMsg(msgInfo{&VoteMessage{vote}, "peer2"})

	// sending the vote for the bigger height
	incrementHeight(vss[1])
	vote = signVote(vss[1], types.PrecommitType, []byte("test"), types.PartSetHeader{})

	cs.handleMsg(msgInfo{&VoteMessage{vote}, peer.ID()})

	select {
	case <-cs.statsMsgQueue:
		t.Errorf("Should not output stats message after receiving the known vote or vote from bigger height")
	case <-time.After(50 * time.Millisecond):
	}
}

func subscribe(evsw events.EventSwitch, protoevent events.Event) <-chan events.Event {
	return events.SubscribeToEvent(evsw, testSubscriber, protoevent)
}