[R4R] Add cdp simulations (#422)

feat: cdp sims
Co-authored-by: rhuairahrighairigh <ruaridh.odonnell@gmail.com>
Co-authored-by: John Maheswaran <john@kava.io>

app/app.go

@@ -330,8 +330,8 @@ func NewApp(logger log.Logger, db dbm.DB, traceStore io.Writer, loadLatest bool,
 		distr.NewAppModule(app.distrKeeper, app.supplyKeeper),
 		staking.NewAppModule(app.stakingKeeper, app.accountKeeper, app.supplyKeeper),
 		slashing.NewAppModule(app.slashingKeeper, app.stakingKeeper),
-		cdp.NewAppModule(app.cdpKeeper, app.pricefeedKeeper, app.supplyKeeper), // TODO how is the order be decided here? Is this order correct?
 		pricefeed.NewAppModule(app.pricefeedKeeper),
+		cdp.NewAppModule(app.cdpKeeper, app.pricefeedKeeper, app.supplyKeeper),
 		auction.NewAppModule(app.auctionKeeper, app.supplyKeeper),
 		bep3.NewAppModule(app.bep3Keeper, app.supplyKeeper),
 		kavadist.NewAppModule(app.kavadistKeeper, app.supplyKeeper),

app/sim_test.go

@@ -37,6 +37,7 @@ import (
 
 	auctionsimops "github.com/kava-labs/kava/x/auction/simulation/operations"
 	bep3simops "github.com/kava-labs/kava/x/bep3/simulation/operations"
+	cdpsimops "github.com/kava-labs/kava/x/cdp/simulation/operations"
 	pricefeedsimops "github.com/kava-labs/kava/x/pricefeed/simulation/operations"
 )
 
@@ -63,6 +64,7 @@ const (
 	OpWeightMsgPlaceBid                                = "op_weight_msg_place_bid"
 	OpWeightMsgPricefeed                               = "op_weight_msg_pricefeed"
 	OpWeightMsgCreateAtomicSwap                        = "op_weight_msg_create_atomic_Swap"
+	OpWeightMsgCdp                                     = "op_weight_msg_cdp"
 )
 
 // TestMain runs setup and teardown code before all tests.
@@ -304,6 +306,17 @@ func testAndRunTxs(app *App, config simulation.Config) []simulation.WeightedOper
 			}(nil),
 			pricefeedsimops.SimulateMsgUpdatePrices(app.pricefeedKeeper),
 		},
+		{
+			func(_ *rand.Rand) int {
+				var v int
+				ap.GetOrGenerate(app.cdc, OpWeightMsgCdp, &v, nil,
+					func(_ *rand.Rand) {
+						v = 100 // TODO
+					})
+				return v
+			}(nil),
+			cdpsimops.SimulateMsgCdp(app.accountKeeper, app.cdpKeeper, app.pricefeedKeeper),
+		},
 	}
 }
 

simulations/README.md

@@ -41,3 +41,5 @@ AWS Batch allows for "array jobs" which are a way of specifying many duplicates
 
 - click on the compute environment name, to get details, then click the link ECS Cluster Name to get details on the actual machines running
 - for array jobs, click the job name to get details of the individual jobs
+
+## Sims - TODO

x/cdp/simulation/genesis.go

@@ -4,19 +4,164 @@ import (
 	"fmt"
 
 	"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/auth"
+	authexported "github.com/cosmos/cosmos-sdk/x/auth/exported"
+	"github.com/cosmos/cosmos-sdk/x/supply"
+	supplyExported "github.com/cosmos/cosmos-sdk/x/supply/exported"
 	"github.com/kava-labs/kava/x/cdp/types"
 )
 
 // RandomizedGenState generates a random GenesisState for cdp
 func RandomizedGenState(simState *module.SimulationState) {
 
-	// TODO implement this fully
-	// - randomly generating the genesis params
-	// - overwriting with genesis provided to simulation
-	cdpGenesis := types.DefaultGenesisState()
+	cdpGenesis := randomCdpGenState(simState.Rand.Intn(2))
+
+	// hacky way to give accounts coins so they can create cdps (coins  includes usdx so it's possible to have sufficient balance to close a cdp)
+	var authGenesis auth.GenesisState
+	simState.Cdc.MustUnmarshalJSON(simState.GenState[auth.ModuleName], &authGenesis)
+	totalCdpCoins := sdk.NewCoins()
+	for _, acc := range authGenesis.Accounts {
+		_, ok := acc.(supplyExported.ModuleAccountI)
+		if ok {
+			continue
+		}
+		coinsToAdd := sdk.NewCoins(
+			sdk.NewCoin("bnb", sdk.NewInt(int64(simState.Rand.Intn(100000000000)))),
+			sdk.NewCoin("xrp", sdk.NewInt(int64(simState.Rand.Intn(100000000000)))),
+			sdk.NewCoin("btc", sdk.NewInt(int64(simState.Rand.Intn(500000000)))),
+			sdk.NewCoin("usdx", sdk.NewInt(int64(simState.Rand.Intn(1000000000)))),
+		)
+		err := acc.SetCoins(acc.GetCoins().Add(coinsToAdd))
+		if err != nil {
+			panic(err)
+		}
+		totalCdpCoins = totalCdpCoins.Add(coinsToAdd)
+		authGenesis.Accounts = replaceOrAppendAccount(authGenesis.Accounts, acc)
+	}
+	simState.GenState[auth.ModuleName] = simState.Cdc.MustMarshalJSON(authGenesis)
+
+	var supplyGenesis supply.GenesisState
+	simState.Cdc.MustUnmarshalJSON(simState.GenState[supply.ModuleName], &supplyGenesis)
+	supplyGenesis.Supply = supplyGenesis.Supply.Add(totalCdpCoins)
+	simState.GenState[supply.ModuleName] = simState.Cdc.MustMarshalJSON(supplyGenesis)
 
 	fmt.Printf("Selected randomly generated %s parameters:\n%s\n", types.ModuleName, codec.MustMarshalJSONIndent(simState.Cdc, cdpGenesis))
 	simState.GenState[types.ModuleName] = simState.Cdc.MustMarshalJSON(cdpGenesis)
 }
+
+// In a list of accounts, replace the first account found with the same address. If not found, append the account.
+func replaceOrAppendAccount(accounts []authexported.GenesisAccount, acc authexported.GenesisAccount) []authexported.GenesisAccount {
+	newAccounts := accounts
+	for i, a := range accounts {
+		if a.GetAddress().Equals(acc.GetAddress()) {
+			newAccounts[i] = acc
+			return newAccounts
+		}
+	}
+	return append(newAccounts, acc)
+}
+
+func randomCdpGenState(selection int) types.GenesisState {
+	switch selection {
+	case 0:
+		return types.GenesisState{
+			Params: types.Params{
+				GlobalDebtLimit:              sdk.NewCoins(sdk.NewInt64Coin("usdx", 100000000000000)),
+				SurplusAuctionThreshold:      types.DefaultSurplusThreshold,
+				DebtAuctionThreshold:         types.DefaultDebtThreshold,
+				SavingsDistributionFrequency: types.DefaultSavingsDistributionFrequency,
+				CollateralParams: types.CollateralParams{
+					{
+						Denom:              "xrp",
+						LiquidationRatio:   sdk.MustNewDecFromStr("2.0"),
+						DebtLimit:          sdk.NewCoins(sdk.NewInt64Coin("usdx", 20000000000000)),
+						StabilityFee:       sdk.MustNewDecFromStr("1.000000004431822130"),
+						LiquidationPenalty: sdk.MustNewDecFromStr("0.075"),
+						AuctionSize:        sdk.NewInt(10000000000),
+						Prefix:             0x20,
+						MarketID:           "xrp:usd",
+						ConversionFactor:   sdk.NewInt(6),
+					},
+					{
+						Denom:              "btc",
+						LiquidationRatio:   sdk.MustNewDecFromStr("1.25"),
+						DebtLimit:          sdk.NewCoins(sdk.NewInt64Coin("usdx", 50000000000000)),
+						StabilityFee:       sdk.MustNewDecFromStr("1.000000000782997609"),
+						LiquidationPenalty: sdk.MustNewDecFromStr("0.05"),
+						AuctionSize:        sdk.NewInt(50000000),
+						Prefix:             0x21,
+						MarketID:           "btc:usd",
+						ConversionFactor:   sdk.NewInt(8),
+					},
+					{
+						Denom:              "bnb",
+						LiquidationRatio:   sdk.MustNewDecFromStr("1.5"),
+						DebtLimit:          sdk.NewCoins(sdk.NewInt64Coin("usdx", 30000000000000)),
+						StabilityFee:       sdk.MustNewDecFromStr("1.000000002293273137"),
+						LiquidationPenalty: sdk.MustNewDecFromStr("0.15"),
+						AuctionSize:        sdk.NewInt(10000000000),
+						Prefix:             0x22,
+						MarketID:           "bnb:usd",
+						ConversionFactor:   sdk.NewInt(8),
+					},
+				},
+				DebtParams: types.DebtParams{
+					{
+						Denom:            "usdx",
+						ReferenceAsset:   "usd",
+						ConversionFactor: sdk.NewInt(6),
+						DebtFloor:        sdk.NewInt(10000000),
+						SavingsRate:      sdk.MustNewDecFromStr("0.95"),
+					},
+				},
+			},
+			StartingCdpID:            types.DefaultCdpStartingID,
+			DebtDenom:                types.DefaultDebtDenom,
+			GovDenom:                 types.DefaultGovDenom,
+			CDPs:                     types.CDPs{},
+			PreviousBlockTime:        types.DefaultPreviousBlockTime,
+			PreviousDistributionTime: types.DefaultPreviousDistributionTime,
+		}
+	case 1:
+		return types.GenesisState{
+			Params: types.Params{
+				GlobalDebtLimit:              sdk.NewCoins(sdk.NewInt64Coin("usdx", 100000000000000)),
+				SurplusAuctionThreshold:      types.DefaultSurplusThreshold,
+				DebtAuctionThreshold:         types.DefaultDebtThreshold,
+				SavingsDistributionFrequency: types.DefaultSavingsDistributionFrequency,
+				CollateralParams: types.CollateralParams{
+					{
+						Denom:              "bnb",
+						LiquidationRatio:   sdk.MustNewDecFromStr("1.5"),
+						DebtLimit:          sdk.NewCoins(sdk.NewInt64Coin("usdx", 100000000000000)),
+						StabilityFee:       sdk.MustNewDecFromStr("1.000000002293273137"),
+						LiquidationPenalty: sdk.MustNewDecFromStr("0.075"),
+						AuctionSize:        sdk.NewInt(10000000000),
+						Prefix:             0x20,
+						MarketID:           "bnb:usd",
+						ConversionFactor:   sdk.NewInt(8),
+					},
+				},
+				DebtParams: types.DebtParams{
+					{
+						Denom:            "usdx",
+						ReferenceAsset:   "usd",
+						ConversionFactor: sdk.NewInt(6),
+						DebtFloor:        sdk.NewInt(10000000),
+						SavingsRate:      sdk.MustNewDecFromStr("0.95"),
+					},
+				},
+			},
+			StartingCdpID:            types.DefaultCdpStartingID,
+			DebtDenom:                types.DefaultDebtDenom,
+			GovDenom:                 types.DefaultGovDenom,
+			CDPs:                     types.CDPs{},
+			PreviousBlockTime:        types.DefaultPreviousBlockTime,
+			PreviousDistributionTime: types.DefaultPreviousDistributionTime,
+		}
+	default:
+		panic("invalid genesis state selector")
+	}
+}

x/cdp/simulation/operations/msgs.go

@@ -0,0 +1,215 @@
+package operations
+
+import (
+	"fmt"
+	"math/rand"
+
+	"github.com/cosmos/cosmos-sdk/baseapp"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/auth"
+	authexported "github.com/cosmos/cosmos-sdk/x/auth/exported"
+	"github.com/cosmos/cosmos-sdk/x/simulation"
+	"github.com/kava-labs/kava/x/cdp"
+	"github.com/kava-labs/kava/x/pricefeed"
+)
+
+// SimulateMsgCdp generates a MsgCreateCdp or MsgDepositCdp with random values.
+func SimulateMsgCdp(ak auth.AccountKeeper, k cdp.Keeper, pfk pricefeed.Keeper) simulation.Operation {
+	return func(r *rand.Rand, app *baseapp.BaseApp, ctx sdk.Context, accs []simulation.Account) (
+		opMsg simulation.OperationMsg, fOps []simulation.FutureOperation, err error) {
+
+		handler := cdp.NewHandler(k)
+		simacc := simulation.RandomAcc(r, accs)
+		acc := ak.GetAccount(ctx, simacc.Address)
+		if acc == nil {
+			return simulation.NoOpMsg(cdp.ModuleName), nil, nil
+		}
+		coins := acc.GetCoins()
+		collateralParams := k.GetParams(ctx).CollateralParams
+		if len(collateralParams) == 0 {
+			return simulation.NoOpMsg(cdp.ModuleName), nil, nil
+		}
+		randCollateralParam := collateralParams[r.Intn(len(collateralParams))]
+		randDebtAsset := randCollateralParam.DebtLimit[r.Intn(len(randCollateralParam.DebtLimit))]
+		randDebtParam, _ := k.GetDebtParam(ctx, randDebtAsset.Denom)
+		if coins.AmountOf(randCollateralParam.Denom).IsZero() {
+			return simulation.NoOpMsg(cdp.ModuleName), nil, nil
+		}
+
+		price, err := pfk.GetCurrentPrice(ctx, randCollateralParam.MarketID)
+		if err != nil {
+			return simulation.NoOpMsg(cdp.ModuleName), nil, err
+		}
+		// convert the price to the same units as the debt param
+		priceShifted := ShiftDec(price.Price, randDebtParam.ConversionFactor)
+
+		existingCDP, found := k.GetCdpByOwnerAndDenom(ctx, acc.GetAddress(), randCollateralParam.Denom)
+		if !found {
+			// calculate the minimum amount of collateral that is needed to create a cdp with the debt floor amount of debt and the minimum liquidation ratio
+			// (debtFloor * liquidationRatio)/priceShifted
+			minCollateralDeposit := (sdk.NewDecFromInt(randDebtParam.DebtFloor).Mul(randCollateralParam.LiquidationRatio)).Quo(priceShifted)
+			// convert to proper collateral units
+			minCollateralDeposit = ShiftDec(minCollateralDeposit, randCollateralParam.ConversionFactor)
+			// convert to integer and always round up
+			minCollateralDepositRounded := minCollateralDeposit.TruncateInt().Add(sdk.OneInt())
+			// if the account has less than the min deposit, return
+			if coins.AmountOf(randCollateralParam.Denom).LT(minCollateralDepositRounded) {
+				return simulation.NoOpMsg(cdp.ModuleName), nil, nil
+			}
+			// set the max collateral deposit to the amount of coins in the account
+			maxCollateralDeposit := coins.AmountOf(randCollateralParam.Denom)
+
+			// randomly select a collateral deposit amount
+			collateralDeposit := sdk.NewInt(int64(simulation.RandIntBetween(r, int(minCollateralDepositRounded.Int64()), int(maxCollateralDeposit.Int64()))))
+			// calculate how much the randomly selected deposit is worth
+			collateralDepositValue := ShiftDec(sdk.NewDecFromInt(collateralDeposit), randCollateralParam.ConversionFactor.Neg()).Mul(priceShifted)
+			// calculate the max amount of debt that could be drawn for the chosen deposit
+			maxDebtDraw := collateralDepositValue.Quo(randCollateralParam.LiquidationRatio).TruncateInt()
+			// randomly select a debt draw amount
+			debtDraw := sdk.NewInt(int64(simulation.RandIntBetween(r, int(randDebtParam.DebtFloor.Int64()), int(maxDebtDraw.Int64()))))
+			msg := cdp.NewMsgCreateCDP(acc.GetAddress(), sdk.NewCoins(sdk.NewCoin(randCollateralParam.Denom, collateralDeposit)), sdk.NewCoins(sdk.NewCoin(randDebtParam.Denom, debtDraw)))
+			err := msg.ValidateBasic()
+			if err != nil {
+				return simulation.NoOpMsg(cdp.ModuleName), nil, fmt.Errorf("expected msg to pass ValidateBasic: %v", err)
+			}
+			ok := submitMsg(msg, handler, ctx)
+			if !ok {
+				return simulation.NoOpMsg(cdp.ModuleName), nil, fmt.Errorf("could not submit create cdp msg")
+			}
+			return simulation.NewOperationMsg(msg, ok, "create cdp"), nil, nil
+		}
+
+		// a cdp already exists, deposit to it, draw debt from it, or repay debt to it
+		// close 25% of the time
+		if canClose(acc, existingCDP, randDebtParam.Denom) && shouldClose(r) {
+			repaymentAmount := coins.AmountOf(randDebtParam.Denom)
+			msg := cdp.NewMsgRepayDebt(acc.GetAddress(), randCollateralParam.Denom, sdk.NewCoins(sdk.NewCoin(randDebtParam.Denom, repaymentAmount)))
+			err := msg.ValidateBasic()
+			if err != nil {
+				return simulation.NoOpMsg(cdp.ModuleName), nil, fmt.Errorf("expected repay (close) msg to pass ValidateBasic: %v", err)
+			}
+			ok := submitMsg(msg, handler, ctx)
+			if !ok {
+				return simulation.NoOpMsg(cdp.ModuleName), nil, fmt.Errorf("could not submit repay (close) msg")
+			}
+			return simulation.NewOperationMsg(msg, ok, "repay debt (close) cdp"), nil, nil
+		}
+
+		// deposit 25% of the time
+		if hasCoins(acc, randCollateralParam.Denom) && shouldDeposit(r) {
+			randDepositAmount := sdk.NewInt(int64(simulation.RandIntBetween(r, 1, int(acc.GetCoins().AmountOf(randCollateralParam.Denom).Int64()))))
+			msg := cdp.NewMsgDeposit(acc.GetAddress(), acc.GetAddress(), sdk.NewCoins(sdk.NewCoin(randCollateralParam.Denom, randDepositAmount)))
+			err := msg.ValidateBasic()
+			if err != nil {
+				return simulation.NoOpMsg(cdp.ModuleName), nil, fmt.Errorf("expected deposit msg to pass ValidateBasic: %v", err)
+			}
+			ok := submitMsg(msg, handler, ctx)
+			if !ok {
+				return simulation.NoOpMsg(cdp.ModuleName), nil, fmt.Errorf("could not submit deposit msg")
+			}
+			return simulation.NewOperationMsg(msg, ok, "deposit to cdp"), nil, nil
+		}
+
+		// draw debt 25% of the time
+		if shouldDraw(r) {
+			collateralShifted := ShiftDec(sdk.NewDecFromInt(existingCDP.Collateral.AmountOf(randCollateralParam.Denom)), randCollateralParam.ConversionFactor.Neg())
+			collateralValue := collateralShifted.Mul(priceShifted)
+			debt := (existingCDP.Principal.Add(existingCDP.AccumulatedFees)).AmountOf(randDebtParam.Denom)
+			maxTotalDebt := collateralValue.Quo(randCollateralParam.LiquidationRatio)
+			maxDebt := maxTotalDebt.Sub(sdk.NewDecFromInt(debt)).TruncateInt().Sub(sdk.OneInt())
+			randDrawAmount := sdk.NewInt(int64(simulation.RandIntBetween(r, 1, int(maxDebt.Int64()))))
+			msg := cdp.NewMsgDrawDebt(acc.GetAddress(), randCollateralParam.Denom, sdk.NewCoins(sdk.NewCoin(randDebtParam.Denom, randDrawAmount)))
+			err := msg.ValidateBasic()
+			if err != nil {
+				return simulation.NoOpMsg(cdp.ModuleName), nil, fmt.Errorf("expected draw msg to pass ValidateBasic: %v", err)
+			}
+			ok := submitMsg(msg, handler, ctx)
+			if !ok {
+				return simulation.NoOpMsg(cdp.ModuleName), nil, fmt.Errorf("could not submit draw msg")
+			}
+			return simulation.NewOperationMsg(msg, ok, "draw debt from cdp"), nil, nil
+
+		}
+
+		// repay debt 25% of the time
+		if hasCoins(acc, randDebtParam.Denom) {
+			debt := (existingCDP.Principal.Add(existingCDP.AccumulatedFees)).AmountOf(randDebtParam.Denom)
+			maxRepay := acc.GetCoins().AmountOf(randDebtParam.Denom)
+			payableDebt := debt.Sub(randDebtParam.DebtFloor)
+			if maxRepay.GT(payableDebt) {
+				maxRepay = payableDebt
+			}
+			randRepayAmount := sdk.NewInt(int64(simulation.RandIntBetween(r, 1, int(maxRepay.Int64()))))
+			if debt.Equal(randDebtParam.DebtFloor) {
+				if acc.GetCoins().AmountOf(randDebtParam.Denom).GTE(debt) {
+					randRepayAmount = debt
+				}
+			}
+			msg := cdp.NewMsgRepayDebt(acc.GetAddress(), randCollateralParam.Denom, sdk.NewCoins(sdk.NewCoin(randDebtParam.Denom, randRepayAmount)))
+			err := msg.ValidateBasic()
+			if err != nil {
+				return simulation.NoOpMsg(cdp.ModuleName), nil, fmt.Errorf("expected repay msg to pass ValidateBasic: %v", err)
+			}
+			ok := submitMsg(msg, handler, ctx)
+			if !ok {
+				return simulation.NoOpMsg(cdp.ModuleName), nil, fmt.Errorf("could not submit repay msg")
+			}
+			return simulation.NewOperationMsg(msg, ok, "repay debt cdp"), nil, nil
+		}
+
+		return simulation.NewOperationMsgBasic(cdp.ModuleName, "no-operation (no valid actions)", "", false, nil), nil, nil
+	}
+}
+
+func submitMsg(msg sdk.Msg, handler sdk.Handler, ctx sdk.Context) (ok bool) {
+	ctx, write := ctx.CacheContext()
+	res := handler(ctx, msg)
+	if res.IsOK() {
+		write()
+	} else {
+		fmt.Println(res.Log)
+	}
+	return res.IsOK()
+}
+
+func shouldDraw(r *rand.Rand) bool {
+	threshold := 50
+	value := simulation.RandIntBetween(r, 1, 100)
+	if value > threshold {
+		return true
+	}
+	return false
+}
+
+func shouldDeposit(r *rand.Rand) bool {
+	threshold := 66
+	value := simulation.RandIntBetween(r, 1, 100)
+	if value > threshold {
+		return true
+	}
+	return false
+}
+
+func hasCoins(acc authexported.Account, denom string) bool {
+	if acc.GetCoins().AmountOf(denom).IsZero() {
+		return false
+	}
+	return true
+}
+
+func shouldClose(r *rand.Rand) bool {
+	threshold := 75
+	value := simulation.RandIntBetween(r, 1, 100)
+	if value > threshold {
+		return true
+	}
+	return false
+}
+
+func canClose(acc authexported.Account, c cdp.CDP, denom string) bool {
+	repaymentAmount := c.Principal.Add(c.AccumulatedFees).AmountOf(denom)
+	if acc.GetCoins().AmountOf(denom).GTE(repaymentAmount) {
+		return true
+	}
+	return false
+}

x/cdp/simulation/operations/utils.go

@@ -0,0 +1,26 @@
+package operations
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+)
+
+func ShiftDec(x sdk.Dec, places sdk.Int) sdk.Dec {
+	neg := places.IsNegative()
+	for i := 0; i < int(abs(places.Int64())); i++ {
+		if neg {
+			x = x.Mul(sdk.MustNewDecFromStr("0.1"))
+		} else {
+			x = x.Mul(sdk.NewDecFromInt(sdk.NewInt(10)))
+		}
+
+	}
+	return x
+}
+
+// abs returns the absolute value of x.
+func abs(x int64) int64 {
+	if x < 0 {
+		return -x
+	}
+	return x
+}

x/cdp/simulation/operations/utils_test.go

@@ -0,0 +1,28 @@
+package operations_test
+
+import (
+	"testing"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/kava-labs/kava/x/cdp/simulation/operations"
+	"github.com/stretchr/testify/require"
+)
+
+func TestShiftDec(t *testing.T) {
+	tests := []struct {
+		value    sdk.Dec
+		shift    sdk.Int
+		expected sdk.Dec
+	}{
+		{sdk.MustNewDecFromStr("5.5"), sdk.NewInt(1), sdk.MustNewDecFromStr("55")},
+		{sdk.MustNewDecFromStr("5.5"), sdk.NewInt(-1), sdk.MustNewDecFromStr("0.55")},
+		{sdk.MustNewDecFromStr("5.5"), sdk.NewInt(2), sdk.MustNewDecFromStr("550")},
+		{sdk.MustNewDecFromStr("5.5"), sdk.NewInt(-2), sdk.MustNewDecFromStr("0.055")},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.value.String(), func(t *testing.T) {
+			require.Equal(t, tt.expected, operations.ShiftDec(tt.value, tt.shift))
+		})
+	}
+}

x/cdp/simulation/params.go

@@ -9,6 +9,5 @@ import (
 // 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/pricefeed/simulation/genesis.go

@@ -5,13 +5,11 @@ import (
 	"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/pricefeed/types"
 	pricefeed "github.com/kava-labs/kava/x/pricefeed/types"
-
-	sdk "github.com/cosmos/cosmos-sdk/types"
 )
 
 // RandomizedGenState generates a random GenesisState for pricefeed
@@ -31,7 +29,6 @@ func RandomizedGenState(simState *module.SimulationState) {
 	}
 	params = types.NewParams(markets)
 	pricefeedGenesis := types.NewGenesisState(params, genPrices)
-
 	fmt.Printf("Selected randomly generated %s parameters:\n%s\n", types.ModuleName, codec.MustMarshalJSONIndent(simState.Cdc, pricefeedGenesis))
 	simState.GenState[types.ModuleName] = simState.Cdc.MustMarshalJSON(pricefeedGenesis)
 }