Add committee simulations (#431)

* first pass at genesis and msgs

* add proposal generation

* add permission generation

* add decoder

* add invariants

* add committee change proposal generator

* improve committee change proposal generation

* fix error formatting

* update sims to v0.38

* Update x/committee/keeper/invariants.go

Co-Authored-By: Denali Marsh <denali@kava.io>

* Update x/committee/keeper/invariants.go

Co-Authored-By: Denali Marsh <denali@kava.io>

* tidy up comments

* tidy up random helpers

* add committee to ImportExport test

* add member check to vote invariant

* fix comment wording

Co-authored-by: Kevin Davis <karzak@users.noreply.github.com>

Co-authored-by: Denali Marsh <denali@kava.io>
Co-authored-by: Kevin Davis <karzak@users.noreply.github.com>

app/params/params.go

@@ -13,4 +13,5 @@ const (
 	DefaultWeightMsgUpdatePrices          int = 50
 	DefaultWeightMsgCdp                   int = 100
 	DefaultWeightMsgClaimReward           int = 50
+	OpWeightSubmitCommitteeChangeProposal int = 50
 )

app/sim_test.go

@@ -8,6 +8,10 @@ import (
 
 	"github.com/stretchr/testify/require"
 
+	abci "github.com/tendermint/tendermint/abci/types"
+	"github.com/tendermint/tendermint/libs/log"
+	dbm "github.com/tendermint/tm-db"
+
 	"github.com/cosmos/cosmos-sdk/baseapp"
 	"github.com/cosmos/cosmos-sdk/simapp"
 	"github.com/cosmos/cosmos-sdk/simapp/helpers"
@@ -23,13 +27,10 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/staking"
 	"github.com/cosmos/cosmos-sdk/x/supply"
 
-	abci "github.com/tendermint/tendermint/abci/types"
-	"github.com/tendermint/tendermint/libs/log"
-	dbm "github.com/tendermint/tm-db"
-
 	"github.com/kava-labs/kava/x/auction"
 	"github.com/kava-labs/kava/x/bep3"
 	"github.com/kava-labs/kava/x/cdp"
+	"github.com/kava-labs/kava/x/committee"
 	"github.com/kava-labs/kava/x/incentive"
 	"github.com/kava-labs/kava/x/kavadist"
 	"github.com/kava-labs/kava/x/pricefeed"
@@ -178,6 +179,7 @@ func TestAppImportExport(t *testing.T) {
 		{app.keys[kavadist.StoreKey], newApp.keys[kavadist.StoreKey], [][]byte{}},
 		{app.keys[pricefeed.StoreKey], newApp.keys[pricefeed.StoreKey], [][]byte{}},
 		{app.keys[validatorvesting.StoreKey], newApp.keys[validatorvesting.StoreKey], [][]byte{}},
+		{app.keys[committee.StoreKey], newApp.keys[committee.StoreKey], [][]byte{}},
 	}
 
 	for _, skp := range storeKeysPrefixes {

x/committee/alias.go

@@ -43,6 +43,10 @@ var (
 	// function aliases
 	NewKeeper                   = keeper.NewKeeper
 	NewQuerier                  = keeper.NewQuerier
+	RegisterInvariants          = keeper.RegisterInvariants
+	ValidCommitteesInvariant    = keeper.ValidCommitteesInvariant
+	ValidProposalsInvariant     = keeper.ValidProposalsInvariant
+	ValidVotesInvariant         = keeper.ValidVotesInvariant
 	DefaultGenesisState         = types.DefaultGenesisState
 	GetKeyFromID                = types.GetKeyFromID
 	GetVoteKey                  = types.GetVoteKey

x/committee/keeper/invariants.go

@@ -0,0 +1,145 @@
+package keeper
+
+import (
+	"fmt"
+	"time"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+
+	"github.com/kava-labs/kava/x/committee/types"
+)
+
+// RegisterInvariants registers all committee invariants
+func RegisterInvariants(ir sdk.InvariantRegistry, k Keeper) {
+
+	ir.RegisterRoute(types.ModuleName, "valid-committees",
+		ValidCommitteesInvariant(k))
+	ir.RegisterRoute(types.ModuleName, "valid-proposals",
+		ValidProposalsInvariant(k))
+	ir.RegisterRoute(types.ModuleName, "valid-votes",
+		ValidVotesInvariant(k))
+}
+
+// ValidCommitteesInvariant verifies that all committees in the store are independently valid
+func ValidCommitteesInvariant(k Keeper) sdk.Invariant {
+	return func(ctx sdk.Context) (string, bool) {
+
+		var validationErr error
+		var invalidCommittee types.Committee
+		k.IterateCommittees(ctx, func(com types.Committee) bool {
+
+			if err := com.Validate(); err != nil {
+				validationErr = err
+				invalidCommittee = com
+				return true
+			}
+			return false
+		})
+
+		broken := validationErr != nil
+		invariantMessage := sdk.FormatInvariant(
+			types.ModuleName,
+			"valid committees",
+			fmt.Sprintf(
+				"\tfound invalid committee, reason: %s\n"+
+					"\tcommittee:\n\t%+v\n",
+				validationErr, invalidCommittee),
+		)
+		return invariantMessage, broken
+	}
+}
+
+// ValidProposalsInvariant verifies that all proposals in the store are valid
+func ValidProposalsInvariant(k Keeper) sdk.Invariant {
+	return func(ctx sdk.Context) (string, bool) {
+
+		var validationErr error
+		var invalidProposal types.Proposal
+		k.IterateProposals(ctx, func(proposal types.Proposal) bool {
+			invalidProposal = proposal
+
+			if err := proposal.PubProposal.ValidateBasic(); err != nil {
+				validationErr = err
+				return true
+			}
+
+			currentTime := ctx.BlockTime()
+			if !currentTime.Equal(time.Time{}) { // this avoids a simulator bug where app.InitGenesis is called with blockTime=0 instead of the correct time
+				if proposal.Deadline.Before(currentTime) {
+					validationErr = fmt.Errorf("deadline after current block time %s", currentTime)
+					return true
+				}
+			}
+
+			com, found := k.GetCommittee(ctx, proposal.CommitteeID)
+			if !found {
+				validationErr = fmt.Errorf("proposal has no committee %d", proposal.CommitteeID)
+				return true
+			}
+
+			if !com.HasPermissionsFor(proposal.PubProposal) {
+				validationErr = fmt.Errorf("proposal not permitted for committee %+v", com)
+				return true
+			}
+
+			return false
+		})
+
+		broken := validationErr != nil
+		invariantMessage := sdk.FormatInvariant(
+			types.ModuleName,
+			"valid proposals",
+			fmt.Sprintf(
+				"\tfound invalid proposal, reason: %s\n"+
+					"\tproposal:\n\t%s\n",
+				validationErr, invalidProposal),
+		)
+		return invariantMessage, broken
+	}
+}
+
+// ValidVotesInvariant verifies that all votes in the store are valid
+func ValidVotesInvariant(k Keeper) sdk.Invariant {
+	return func(ctx sdk.Context) (string, bool) {
+
+		var validationErr error
+		var invalidVote types.Vote
+		k.IterateVotes(ctx, func(vote types.Vote) bool {
+			invalidVote = vote
+
+			if vote.Voter.Empty() {
+				validationErr = fmt.Errorf("empty voter address")
+				return true
+			}
+
+			proposal, found := k.GetProposal(ctx, vote.ProposalID)
+			if !found {
+				validationErr = fmt.Errorf("vote has no proposal %d", vote.ProposalID)
+				return true
+			}
+
+			com, found := k.GetCommittee(ctx, proposal.CommitteeID)
+			if !found {
+				validationErr = fmt.Errorf("vote's proposal has no committee %d", proposal.CommitteeID)
+				return true
+			}
+			if !com.HasMember(vote.Voter) {
+				validationErr = fmt.Errorf("voter is not a member of committee %+v", com)
+				return true
+			}
+
+			return false
+		})
+
+		broken := validationErr != nil
+		invariantMessage := sdk.FormatInvariant(
+			types.ModuleName,
+			"valid votes",
+			fmt.Sprintf(
+				"\tfound invalid vote, reason: %s\n"+
+					"\tvote:\n\t%+v\n",
+				validationErr, invalidVote),
+		)
+		return invariantMessage, broken
+	}
+}

x/committee/module.go

@@ -95,7 +95,9 @@ func (AppModule) Name() string {
 }
 
 // RegisterInvariants register module invariants
-func (AppModule) RegisterInvariants(_ sdk.InvariantRegistry) {}
+func (am AppModule) RegisterInvariants(ir sdk.InvariantRegistry) {
+	RegisterInvariants(ir, am.keeper)
+}
 
 // Route module message route name
 func (AppModule) Route() string {
@@ -149,12 +151,12 @@ func (AppModuleBasic) GenerateGenesisState(simState *module.SimulationState) {
 	simulation.RandomizedGenState(simState)
 }
 
-// TODO
-func (AppModuleBasic) ProposalContents(_ module.SimulationState) []sim.WeightedProposalContent {
-	return nil
+// ProposalContents returns functions that generate gov proposals for the module
+func (am AppModule) ProposalContents(simState module.SimulationState) []sim.WeightedProposalContent {
+	return simulation.ProposalContents(am.keeper, simState.ParamChanges)
 }
 
-// RandomizedParams returns functions that generate params for the module.
+// RandomizedParams returns functions that generate params for the module
 func (AppModuleBasic) RandomizedParams(r *rand.Rand) []sim.ParamChange {
 	return nil
 }
@@ -164,7 +166,7 @@ func (AppModuleBasic) RegisterStoreDecoder(sdr sdk.StoreDecoderRegistry) {
 	sdr[StoreKey] = simulation.DecodeStore
 }
 
-// WeightedOperations returns the all the auction module operations with their respective weights.
+// WeightedOperations returns the module operations for use in simulations
 func (am AppModule) WeightedOperations(simState module.SimulationState) []sim.WeightedOperation {
-	return nil // TODO simulation.WeightedOperations(simState.AppParams, simState.Cdc, am.accountKeeper, am.keeper)
+	return simulation.WeightedOperations(simState.AppParams, simState.Cdc, am.accountKeeper, am.keeper, simState.Contents)
 }

x/committee/simulation/common.go

@@ -0,0 +1,71 @@
+package simulation
+
+import (
+	"fmt"
+	"math/big"
+	"math/rand"
+	"time"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/simulation"
+)
+
+func RandomAddresses(r *rand.Rand, accs []simulation.Account) []sdk.AccAddress {
+	r.Shuffle(len(accs), func(i, j int) {
+		accs[i], accs[j] = accs[j], accs[i]
+	})
+
+	var addresses []sdk.AccAddress
+	numAddresses := r.Intn(len(accs) + 1)
+	for i := 0; i < numAddresses; i++ {
+		addresses = append(addresses, accs[i].Address)
+	}
+	return addresses
+}
+
+func RandomPositiveDuration(r *rand.Rand, inclusiveMin, exclusiveMax time.Duration) (time.Duration, error) {
+	min := int64(inclusiveMin)
+	max := int64(exclusiveMax)
+	if min < 0 || max < 0 {
+		return 0, fmt.Errorf("min and max must be positive")
+	}
+	if min >= max {
+		return 0, fmt.Errorf("max must be < min")
+	}
+	randPositiveInt64 := r.Int63n(max-min) + min
+	return time.Duration(randPositiveInt64), nil
+}
+
+func RandomTime(r *rand.Rand, inclusiveMin, exclusiveMax time.Time) (time.Time, error) {
+	if exclusiveMax.Before(inclusiveMin) {
+		return time.Time{}, fmt.Errorf("max must be > min")
+	}
+	period := exclusiveMax.Sub(inclusiveMin)
+	subPeriod, err := RandomPositiveDuration(r, 0, period)
+	if err != nil {
+		return time.Time{}, err
+	}
+	return inclusiveMin.Add(subPeriod), nil
+}
+
+// RandInt randomly generates an sdk.Int in the range [inclusiveMin, inclusiveMax]. It works for negative and positive integers.
+func RandIntInclusive(r *rand.Rand, inclusiveMin, inclusiveMax sdk.Int) (sdk.Int, error) {
+	if inclusiveMin.GT(inclusiveMax) {
+		return sdk.Int{}, fmt.Errorf("min larger than max")
+	}
+	return RandInt(r, inclusiveMin, inclusiveMax.Add(sdk.OneInt()))
+}
+
+// RandInt randomly generates an sdk.Int in the range [inclusiveMin, exclusiveMax). It works for negative and positive integers.
+func RandInt(r *rand.Rand, inclusiveMin, exclusiveMax sdk.Int) (sdk.Int, error) {
+	// validate input
+	if inclusiveMin.GTE(exclusiveMax) {
+		return sdk.Int{}, fmt.Errorf("min larger or equal to max")
+	}
+	// shift the range to start at 0
+	shiftedRange := exclusiveMax.Sub(inclusiveMin) // should always be positive given the check above
+	// randomly pick from the shifted range
+	shiftedRandInt := sdk.NewIntFromBigInt(new(big.Int).Rand(r, shiftedRange.BigInt()))
+	// shift back to the original range
+	return shiftedRandInt.Add(inclusiveMin), nil
+}

x/committee/simulation/decoder.go

@@ -1,13 +1,43 @@
 package simulation
 
 import (
+	"bytes"
+	"fmt"
+
 	"github.com/cosmos/cosmos-sdk/codec"
 
 	"github.com/tendermint/tendermint/libs/kv"
+
+	"github.com/kava-labs/kava/x/committee/types"
 )
 
 // DecodeStore unmarshals the KVPair's Value to the corresponding module type
 func DecodeStore(cdc *codec.Codec, kvA, kvB kv.Pair) string {
-	// TODO implement this
-	return ""
+	switch {
+	case bytes.Equal(kvA.Key[:1], types.CommitteeKeyPrefix):
+		var committeeA, committeeB types.Committee
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvA.Value, &committeeA)
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvB.Value, &committeeB)
+		return fmt.Sprintf("%v\n%v", committeeA, committeeB)
+
+	case bytes.Equal(kvA.Key[:1], types.ProposalKeyPrefix):
+		var proposalA, proposalB types.Proposal
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvA.Value, &proposalA)
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvB.Value, &proposalB)
+		return fmt.Sprintf("%v\n%v", proposalA, proposalB)
+
+	case bytes.Equal(kvA.Key[:1], types.VoteKeyPrefix):
+		var voteA, voteB types.Vote
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvA.Value, &voteA)
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvB.Value, &voteB)
+		return fmt.Sprintf("%v\n%v", voteA, voteB)
+
+	case bytes.Equal(kvA.Key[:1], types.NextProposalIDKey):
+		proposalIDA := types.Uint64FromBytes(kvA.Value)
+		proposalIDB := types.Uint64FromBytes(kvB.Value)
+		return fmt.Sprintf("%d\n%d", proposalIDA, proposalIDB)
+
+	default:
+		panic(fmt.Sprintf("invalid %s key prefix %X", types.ModuleName, kvA.Key[:1]))
+	}
 }

x/committee/simulation/decoder_test.go

@@ -0,0 +1,77 @@
+package simulation
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"github.com/tendermint/tendermint/libs/kv"
+
+	"github.com/cosmos/cosmos-sdk/codec"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	govtypes "github.com/cosmos/cosmos-sdk/x/gov/types"
+
+	"github.com/kava-labs/kava/x/committee/types"
+)
+
+func makeTestCodec() (cdc *codec.Codec) {
+	cdc = codec.New()
+	sdk.RegisterCodec(cdc)
+	govtypes.RegisterCodec(cdc)
+	types.RegisterCodec(cdc)
+	return cdc
+}
+
+func TestDecodeStore(t *testing.T) {
+	cdc := makeTestCodec()
+
+	committee := types.NewCommittee(
+		12,
+		"This committee is for testing.",
+		nil,
+		[]types.Permission{types.TextPermission{}},
+		sdk.MustNewDecFromStr("0.667"),
+		time.Hour*24*7,
+	)
+	proposal := types.Proposal{
+		ID:          34,
+		CommitteeID: 12,
+		Deadline:    time.Date(1998, time.January, 1, 1, 0, 0, 0, time.UTC),
+		PubProposal: govtypes.NewTextProposal("A Title", "A description of this proposal."),
+	}
+	vote := types.Vote{
+		ProposalID: 9,
+		Voter:      nil,
+	}
+
+	kvPairs := kv.Pairs{
+		kv.Pair{Key: types.CommitteeKeyPrefix, Value: cdc.MustMarshalBinaryLengthPrefixed(&committee)},
+		kv.Pair{Key: types.ProposalKeyPrefix, Value: cdc.MustMarshalBinaryLengthPrefixed(&proposal)},
+		kv.Pair{Key: types.VoteKeyPrefix, Value: cdc.MustMarshalBinaryLengthPrefixed(&vote)},
+		kv.Pair{Key: types.NextProposalIDKey, Value: sdk.Uint64ToBigEndian(10)},
+		kv.Pair{Key: []byte{0x99}, Value: []byte{0x99}},
+	}
+
+	tests := []struct {
+		name        string
+		expectedLog string
+	}{
+		{"Committee", fmt.Sprintf("%v\n%v", committee, committee)},
+		{"Proposal", fmt.Sprintf("%v\n%v", proposal, proposal)},
+		{"Vote", fmt.Sprintf("%v\n%v", vote, vote)},
+		{"NextProposalID", "10\n10"},
+		{"other", ""},
+	}
+	for i, tt := range tests {
+		i, tt := i, tt
+		t.Run(tt.name, func(t *testing.T) {
+			switch i {
+			case len(tests) - 1:
+				require.Panics(t, func() { DecodeStore(cdc, kvPairs[i], kvPairs[i]) }, tt.name)
+			default:
+				require.Equal(t, tt.expectedLog, DecodeStore(cdc, kvPairs[i], kvPairs[i]), tt.name)
+			}
+		})
+	}
+}

x/committee/simulation/genesis.go

@@ -2,21 +2,122 @@ package simulation
 
 import (
 	"fmt"
+	"math/rand"
+	"time"
 
-	"github.com/cosmos/cosmos-sdk/codec"
+	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/module"
+	"github.com/cosmos/cosmos-sdk/x/simulation"
 
 	"github.com/kava-labs/kava/x/committee/types"
 )
 
+const (
+	// Block time params are un-exported constants in cosmos-sdk/x/simulation.
+	// Copy them here in lieu of importing them.
+	minTimePerBlock time.Duration = (10000 / 2) * time.Second
+	maxTimePerBlock time.Duration = 10000 * time.Second
+	// Calculate the average block time
+	AverageBlockTime time.Duration = (maxTimePerBlock - minTimePerBlock) / 2
+
+	FallbackCommitteeID uint64 = 0
+)
+
 // RandomizedGenState generates a random GenesisState for the module
 func RandomizedGenState(simState *module.SimulationState) {
+	r := simState.Rand
 
-	// TODO implement this fully
-	// - randomly generating the genesis params
-	// - overwriting with genesis provided to simulation
-	genesisState := types.DefaultGenesisState()
+	// Create an always present committee with god permissions to ensure any randomly generated proposal can always be submitted.
+	// Without this, proposals can often not be submitted as there aren't any committees with the right set of permissions available.
+	// It provides more control over how often different proposal types happen during simulation.
+	// It also makes the code simpler--proposals can just be randomly generated and submitted without having to comply to permissions that happen to be available at the time.
+	fallbackCommittee := types.NewCommittee(
+		FallbackCommitteeID,
+		"A committee with god permissions that will always be in state and not deleted. It ensures any generated proposal can always be submitted and passed.",
+		RandomAddresses(r, simState.Accounts),
+		[]types.Permission{types.GodPermission{}},
+		sdk.MustNewDecFromStr("0.5"),
+		AverageBlockTime*10,
+	)
 
-	fmt.Printf("Selected randomly generated %s parameters:\n%s\n", types.ModuleName, codec.MustMarshalJSONIndent(simState.Cdc, genesisState))
+	// Create other committees
+	numCommittees := r.Intn(100)
+	committees := []types.Committee{fallbackCommittee}
+	for i := 0; i < numCommittees; i++ {
+		com, err := RandomCommittee(r, firstNAccounts(25, simState.Accounts), paramChangeToAllowedParams(simState.ParamChanges))
+		if err != nil {
+			panic(err)
+		}
+		committees = append(committees, com)
+	}
+
+	// Add genesis state to simState
+	genesisState := types.NewGenesisState(
+		types.DefaultNextProposalID,
+		committees,
+		[]types.Proposal{},
+		[]types.Vote{},
+	)
+	fmt.Printf("Selected randomly generated %s parameters:\n%s\n", types.ModuleName, []byte{})
 	simState.GenState[types.ModuleName] = simState.Cdc.MustMarshalJSON(genesisState)
 }
+
+func RandomCommittee(r *rand.Rand, availableAccs []simulation.Account, allowedParams []types.AllowedParam) (types.Committee, error) {
+	// pick committee members
+	if len(availableAccs) < 1 {
+		return types.Committee{}, fmt.Errorf("must be ≥ 1 addresses")
+	}
+	var members []sdk.AccAddress
+	for len(members) < 1 {
+		members = RandomAddresses(r, availableAccs)
+	}
+
+	// pick proposal duration
+	dur, err := RandomPositiveDuration(r, 0, AverageBlockTime*10)
+	if err != nil {
+		return types.Committee{}, err
+	}
+
+	// pick committee vote threshold, must be in interval (0,1]
+	threshold := simulation.RandomDecAmount(r, sdk.MustNewDecFromStr("1").Sub(sdk.SmallestDec())).Add(sdk.SmallestDec())
+
+	return types.NewCommittee(
+		r.Uint64(), // could collide with other committees, but unlikely
+		simulation.RandStringOfLength(r, r.Intn(types.MaxCommitteeDescriptionLength+1)),
+		members,
+		RandomPermissions(r, allowedParams),
+		threshold,
+		dur,
+	), nil
+}
+
+func RandomPermissions(r *rand.Rand, allowedParams []types.AllowedParam) []types.Permission {
+	var permissions []types.Permission
+	if r.Intn(100) < 50 {
+		permissions = append(permissions, types.TextPermission{})
+	}
+	if r.Intn(100) < 50 {
+		r.Shuffle(len(allowedParams), func(i, j int) {
+			allowedParams[i], allowedParams[j] = allowedParams[j], allowedParams[i]
+		})
+		permissions = append(permissions,
+			types.ParamChangePermission{
+				AllowedParams: allowedParams[:r.Intn(len(allowedParams)+1)],
+			})
+	}
+	return permissions
+}
+
+func paramChangeToAllowedParams(paramChanges []simulation.ParamChange) []types.AllowedParam {
+	var allowedParams []types.AllowedParam
+	for _, pc := range paramChanges {
+		allowedParams = append(
+			allowedParams,
+			types.AllowedParam{
+				Subspace: pc.Subspace,
+				Key:      pc.Key,
+			},
+		)
+	}
+	return allowedParams
+}

x/committee/simulation/operations.go

@@ -0,0 +1,199 @@
+package simulation
+
+import (
+	"fmt"
+	"math/rand"
+
+	"github.com/cosmos/cosmos-sdk/baseapp"
+	"github.com/cosmos/cosmos-sdk/codec"
+	"github.com/cosmos/cosmos-sdk/simapp/helpers"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	authexported "github.com/cosmos/cosmos-sdk/x/auth/exported"
+	"github.com/cosmos/cosmos-sdk/x/simulation"
+
+	"github.com/kava-labs/kava/x/committee/keeper"
+	"github.com/kava-labs/kava/x/committee/types"
+)
+
+var (
+	proposalPassPercentage = 0.9
+)
+
+type AccountKeeper interface {
+	GetAccount(sdk.Context, sdk.AccAddress) authexported.Account
+}
+
+// WeightedOperations creates an operation (with weight) for each type of proposal generator.
+// Custom proposal generators can be added for more control over types of proposal submitted, eg to increase likelyhood of particular cdp param changes.
+func WeightedOperations(appParams simulation.AppParams, cdc *codec.Codec, ak AccountKeeper,
+	k keeper.Keeper, wContents []simulation.WeightedProposalContent) simulation.WeightedOperations {
+
+	var wops simulation.WeightedOperations
+
+	for _, wContent := range wContents {
+		wContent := wContent // pin variable
+		if wContent.AppParamsKey == OpWeightSubmitCommitteeChangeProposal {
+			// don't include committee change/delete proposals as they're not enabled for submission to committees
+			continue
+		}
+		var weight int
+		// TODO this doesn't allow weights to be different from what they are in the gov module
+		appParams.GetOrGenerate(cdc, wContent.AppParamsKey, &weight, nil,
+			func(_ *rand.Rand) { weight = wContent.DefaultWeight })
+
+		wops = append(
+			wops,
+			simulation.NewWeightedOperation(
+				weight,
+				SimulateMsgSubmitProposal(ak, k, wContent.ContentSimulatorFn),
+			),
+		)
+	}
+	return wops
+}
+
+// SimulateMsgSubmitProposal creates a proposal using the passed contentSimulatorFn and tries to find a committee that has permissions for it. If it can't then it uses the fallback committee.
+// If the fallback committee isn't there (eg when using an non-generated genesis) and no committee can be found this emits a no-op msg and doesn't do anything.
+// For each submit proposal msg, future ops for the vote messages are generated. Sometimes it doesn't run enough votes to allow the proposal to timeout - the likelihood of this happening is controlled by a parameter.
+func SimulateMsgSubmitProposal(ak AccountKeeper, k keeper.Keeper, contentSim simulation.ContentSimulatorFn) simulation.Operation {
+	return func(r *rand.Rand, app *baseapp.BaseApp, ctx sdk.Context, accs []simulation.Account, chainID string) (simulation.OperationMsg, []simulation.FutureOperation, error) {
+
+		// 1) Send  a submit proposal msg
+
+		committees := k.GetCommittees(ctx)
+		// shuffle committees to ensure proposals are distributed across them evenly
+		r.Shuffle(len(committees), func(i, j int) {
+			committees[i], committees[j] = committees[j], committees[i]
+		})
+		// move fallback committee to the end of slice
+		for i, c := range committees {
+			if c.ID == FallbackCommitteeID {
+				// switch places with last element
+				committees[i], committees[len(committees)-1] = committees[len(committees)-1], committees[i]
+			}
+		}
+		// pick a committee that has permissions for proposal
+		pp := types.PubProposal(contentSim(r, ctx, accs))
+		var selectedCommittee types.Committee
+		var found bool
+		for _, c := range committees {
+			if c.HasPermissionsFor(pp) {
+				selectedCommittee = c
+				found = true
+				break
+			}
+		}
+		if !found {
+			// fallback committee was not present, this should only happen if not using the generated genesis state
+			return simulation.NewOperationMsgBasic(types.ModuleName, "no-operation (no committee has permissions for proposal)", "", false, nil), nil, nil
+		}
+
+		// create the msg and tx
+		proposer := selectedCommittee.Members[r.Intn(len(selectedCommittee.Members))] // won't panic as committees must have ≥ 1 members
+		msg := types.NewMsgSubmitProposal(
+			pp,
+			proposer,
+			selectedCommittee.ID,
+		)
+		account := ak.GetAccount(ctx, proposer)
+		fees, err := simulation.RandomFees(r, ctx, account.SpendableCoins(ctx.BlockTime()))
+		if err != nil {
+			return simulation.NoOpMsg(types.ModuleName), nil, err
+		}
+		proposerAcc, found := simulation.FindAccount(accs, proposer)
+		if !found {
+			return simulation.NoOpMsg(types.ModuleName), nil, fmt.Errorf("address not in account list")
+		}
+		tx := helpers.GenTx(
+			[]sdk.Msg{msg},
+			fees,
+			helpers.DefaultGenTxGas,
+			chainID,
+			[]uint64{account.GetAccountNumber()},
+			[]uint64{account.GetSequence()},
+			proposerAcc.PrivKey,
+		)
+		// submit tx
+		_, result, err := app.Deliver(tx)
+		if err != nil {
+			// to aid debugging, add the stack trace to the comment field of the returned opMsg
+			return simulation.NewOperationMsg(msg, false, fmt.Sprintf("%+v", err)), nil, err
+		}
+		// to aid debugging, add the result log to the comment field
+		submitOpMsg := simulation.NewOperationMsg(msg, true, result.Log)
+
+		// 2) Schedule vote operations
+
+		// get submitted proposal
+		proposalID := types.Uint64FromBytes(result.Data)
+		proposal, found := k.GetProposal(ctx, proposalID)
+		if !found {
+			return simulation.NoOpMsg(types.ModuleName), nil, fmt.Errorf("can't find proposal with ID '%d'", proposalID)
+		}
+
+		// pick the voters
+		// num voters determined by whether the proposal should pass or not
+		numMembers := int64(len(selectedCommittee.Members))
+		majority := selectedCommittee.VoteThreshold.Mul(sdk.NewInt(numMembers).ToDec()).Ceil().TruncateInt64()
+
+		numVoters := r.Int63n(majority) // in interval [0, majority)
+		shouldPass := r.Float64() < proposalPassPercentage
+		if shouldPass {
+			numVoters = majority + r.Int63n(numMembers-majority+1) // in interval [majority, numMembers]
+		}
+		voters := selectedCommittee.Members[:numVoters]
+
+		// schedule vote operations
+		var futureOps []simulation.FutureOperation
+		for _, v := range voters {
+			voteTime, err := RandomTime(r, ctx.BlockTime(), proposal.Deadline)
+			if err != nil {
+				return simulation.NoOpMsg(types.ModuleName), nil, fmt.Errorf("random time generation failed: %w", err)
+			}
+			fop := simulation.FutureOperation{
+				BlockTime: voteTime,
+				Op:        SimulateMsgVote(k, ak, v, proposal.ID),
+			}
+			futureOps = append(futureOps, fop)
+		}
+
+		return submitOpMsg, futureOps, nil
+	}
+}
+
+func SimulateMsgVote(k keeper.Keeper, ak AccountKeeper, voter sdk.AccAddress, proposalID uint64) simulation.Operation {
+	return func(r *rand.Rand, app *baseapp.BaseApp, ctx sdk.Context, accs []simulation.Account, chainID string) (
+		opMsg simulation.OperationMsg, fOps []simulation.FutureOperation, err error) {
+
+		msg := types.NewMsgVote(voter, proposalID)
+
+		account := ak.GetAccount(ctx, voter)
+		fees, err := simulation.RandomFees(r, ctx, account.SpendableCoins(ctx.BlockTime()))
+		if err != nil {
+			return simulation.NoOpMsg(types.ModuleName), nil, err
+		}
+
+		voterAcc, found := simulation.FindAccount(accs, voter)
+		if !found {
+			return simulation.NoOpMsg(types.ModuleName), nil, fmt.Errorf("address not in account list")
+		}
+
+		tx := helpers.GenTx(
+			[]sdk.Msg{msg},
+			fees,
+			helpers.DefaultGenTxGas,
+			chainID,
+			[]uint64{account.GetAccountNumber()},
+			[]uint64{account.GetSequence()},
+			voterAcc.PrivKey,
+		)
+
+		_, result, err := app.Deliver(tx)
+		if err != nil {
+			// to aid debugging, add the stack trace to the comment field of the returned opMsg
+			return simulation.NewOperationMsg(msg, false, fmt.Sprintf("%+v", err)), nil, err
+		}
+		// to aid debugging, add the result log to the comment field
+		return simulation.NewOperationMsg(msg, true, result.Log), nil, nil
+	}
+}

x/committee/simulation/params.go

@@ -1,14 +0,0 @@
-package simulation
-
-import (
-	"math/rand"
-
-	"github.com/cosmos/cosmos-sdk/x/simulation"
-)
-
-// ParamChanges defines the parameters that can be modified by param change proposals
-// on the simulation
-func ParamChanges(r *rand.Rand) []simulation.ParamChange {
-	// TODO implement this
-	return []simulation.ParamChange{}
-}

x/committee/simulation/proposals.go

@@ -0,0 +1,173 @@
+package simulation
+
+import (
+	"fmt"
+	"math/rand"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	govtypes "github.com/cosmos/cosmos-sdk/x/gov/types"
+	"github.com/cosmos/cosmos-sdk/x/simulation"
+
+	appparams "github.com/kava-labs/kava/app/params"
+	"github.com/kava-labs/kava/x/committee/keeper"
+	"github.com/kava-labs/kava/x/committee/types"
+)
+
+const OpWeightSubmitCommitteeChangeProposal = "op_weight_submit_committee_change_proposal"
+
+// ProposalContents defines the module weighted proposals' contents
+func ProposalContents(k keeper.Keeper, paramChanges []simulation.ParamChange) []simulation.WeightedProposalContent {
+	return []simulation.WeightedProposalContent{
+		{
+			AppParamsKey:       OpWeightSubmitCommitteeChangeProposal,
+			DefaultWeight:      appparams.OpWeightSubmitCommitteeChangeProposal,
+			ContentSimulatorFn: SimulateCommitteeChangeProposalContent(k, paramChanges),
+		},
+	}
+}
+
+// SimulateCommitteeChangeProposalContent generates gov proposal contents that either:
+// - create new committees
+// - change existing committees
+// - delete committees
+// It does not alter the fallback committee.
+func SimulateCommitteeChangeProposalContent(k keeper.Keeper, paramChanges []simulation.ParamChange) simulation.ContentSimulatorFn {
+	return func(r *rand.Rand, ctx sdk.Context, accs []simulation.Account) govtypes.Content {
+		allowedParams := paramChangeToAllowedParams(paramChanges)
+
+		// get current committees, ignoring the fallback committee
+		var committees []types.Committee
+		k.IterateCommittees(ctx, func(com types.Committee) bool {
+			if com.ID != FallbackCommitteeID {
+				committees = append(committees, com)
+			}
+			return false
+		})
+		if len(committees) < 1 { // create a committee if none exist
+			com, err := RandomCommittee(r, firstNAccounts(25, accs), allowedParams) // limit num members to avoid overflowing hardcoded gov ops gas limit
+			if err != nil {
+				panic(err)
+			}
+			return types.NewCommitteeChangeProposal(
+				simulation.RandStringOfLength(r, 10),
+				simulation.RandStringOfLength(r, 100),
+				com,
+			)
+		}
+
+		// create a proposal content
+
+		var content govtypes.Content
+		switch choice := r.Intn(100); {
+
+		// create committee
+		case choice < 20:
+			com, err := RandomCommittee(r, firstNAccounts(25, accs), allowedParams) // limit num members to avoid overflowing hardcoded gov ops gas limit
+			if err != nil {
+				panic(err)
+			}
+			content = types.NewCommitteeChangeProposal(
+				simulation.RandStringOfLength(r, 10),
+				simulation.RandStringOfLength(r, 100),
+				com,
+			)
+
+		// update committee
+		case choice < 80:
+			com := committees[r.Intn(len(committees))]
+
+			// update members
+			if r.Intn(100) < 50 {
+				if len(accs) == 0 {
+					panic("must have at least one account availabel to use as committee member")
+				}
+				var members []sdk.AccAddress
+				for len(members) < 1 {
+					members = RandomAddresses(r, firstNAccounts(25, accs)) // limit num members to avoid overflowing hardcoded gov ops gas limit
+				}
+				com.Members = members
+			}
+			// update permissions
+			if r.Intn(100) < 50 {
+				com.Permissions = RandomPermissions(r, allowedParams)
+			}
+			// update proposal duration
+			if r.Intn(100) < 50 {
+				dur, err := RandomPositiveDuration(r, 0, AverageBlockTime*100)
+				if err != nil {
+					panic(err)
+				}
+				com.ProposalDuration = dur
+			}
+			// update vote threshold
+			if r.Intn(100) < 50 {
+				// VoteThreshold must be in interval (0,1]
+				com.VoteThreshold = simulation.RandomDecAmount(r, sdk.MustNewDecFromStr("1").Sub(sdk.SmallestDec())).Add(sdk.SmallestDec())
+			}
+
+			content = types.NewCommitteeChangeProposal(
+				simulation.RandStringOfLength(r, 10),
+				simulation.RandStringOfLength(r, 100),
+				com,
+			)
+
+		// delete committee
+		default:
+			com := committees[r.Intn(len(committees))]
+			content = types.NewCommitteeDeleteProposal(
+				simulation.RandStringOfLength(r, 10),
+				simulation.RandStringOfLength(r, 100),
+				com.ID,
+			)
+		}
+
+		return content
+	}
+}
+
+/*
+// Example custom ParamChangeProposal generator to only generate change to interesting cdp params.
+// This allows more control over what params are changed within a simulation.
+func SimulateCDPParamChangeProposalContent(cdpKeeper cdpkeeper.Keeper, paramChangePool []simulation.ParamChange) simulation.ContentSimulatorFn {
+	return func(r *rand.Rand, ctx sdk.Context, _ []simulation.Account) govtypes.Content {
+
+		var paramChanges []paramstypes.ParamChange
+
+		// alter sub params
+		cp := cdpKeeper.GetParams(ctx).CollateralParams
+		if len(cp) == 0 {
+			return nil
+		}
+		cp[0].StabilityFee = sdk.MustNewDecFromStr("0.000001") // TODO generate
+		paramChanges = append(
+			paramChanges,
+			paramstypes.NewParamChange(cdptypes.ModuleName, "?", string(cdptypes.ModuleCdc.MustMarshalJSON(cp))),
+		)
+
+		// alter normal param
+		for _, pc := range paramChangePool {
+			if pc.Subspace == cdptypes.ModuleName && pc.Key == string(cdptypes.KeyGlobalDebtLimit) {
+				paramChanges = append(
+					paramChanges,
+					paramstypes.NewParamChange(pc.Subspace, pc.Key, pc.SimValue(r)),
+				)
+			}
+		}
+
+		return paramstypes.NewParameterChangeProposal(
+			simulation.RandStringOfLength(r, 140),  // title
+			simulation.RandStringOfLength(r, 5000), // description
+			paramChanges,                           // set of changes
+		)
+	}
+}
+*/
+func firstNAccounts(n int, accs []simulation.Account) []simulation.Account {
+	if n < 0 {
+		panic(fmt.Sprintf("n must be ≥ 0"))
+	}
+	if n > len(accs) {
+		return accs
+	}
+	return accs[:n]
+}

x/committee/types/committee.go

@@ -63,31 +63,30 @@ func (c Committee) Validate() error {
 	for _, m := range c.Members {
 		// check there are no duplicate members
 		if _, ok := addressMap[m.String()]; ok {
-			return fmt.Errorf("duplicate member found in committee, %s", m)
+			return fmt.Errorf("committe cannot have duplicate members, %s", m)
 		}
 		// check for valid addresses
 		if m.Empty() {
-			return fmt.Errorf("committee %d invalid: found empty member address", c.ID)
+			return fmt.Errorf("committee cannot have empty member address")
 		}
 		addressMap[m.String()] = true
-
 	}
 
 	if len(c.Members) == 0 {
-		return fmt.Errorf("committee %d invalid: cannot have zero members", c.ID)
+		return fmt.Errorf("committee cannot have zero members")
 	}
 
 	if len(c.Description) > MaxCommitteeDescriptionLength {
-		return fmt.Errorf("invalid description")
+		return fmt.Errorf("description length %d longer than max allowed %d", len(c.Description), MaxCommitteeDescriptionLength)
 	}
 
 	// threshold must be in the range (0,1]
 	if c.VoteThreshold.IsNil() || c.VoteThreshold.LTE(sdk.ZeroDec()) || c.VoteThreshold.GT(sdk.NewDec(1)) {
-		return fmt.Errorf("invalid threshold")
+		return fmt.Errorf("invalid threshold: %s", c.VoteThreshold)
 	}
 
 	if c.ProposalDuration < 0 {
-		return fmt.Errorf("invalid proposal duration")
+		return fmt.Errorf("invalid proposal duration: %s", c.ProposalDuration)
 	}
 
 	return nil

x/committee/types/genesis.go

@@ -65,7 +65,7 @@ func (gs GenesisState) Validate() error {
 		}
 	}
 
-	// validate proposals - pp.Val, no duplicate IDs, no ids >= nextID, committee needs to exist
+	// validate proposals
 	proposalMap := make(map[uint64]bool, len(gs.Proposals))
 	for _, p := range gs.Proposals {
 		// check there are no duplicate IDs