chore(tests): add rewards simulation tests

app/modules.go

@@ -154,7 +154,7 @@ func appModules(
 		pools.NewAppModule(appCodec, app.PoolsKeeper),
 		restaking.NewAppModule(appCodec, app.RestakingKeeper, app.AccountKeeper, app.BankKeeper, app.PoolsKeeper, app.OperatorsKeeper, app.ServicesKeeper),
 		assets.NewAppModule(appCodec, app.AssetsKeeper),
-		rewards.NewAppModule(appCodec, app.RewardsKeeper),
+		rewards.NewAppModule(appCodec, app.RewardsKeeper, app.AccountKeeper, app.BankKeeper, app.PoolsKeeper, app.OperatorsKeeper, app.ServicesKeeper),
 		liquidvesting.NewAppModule(appCodec, app.LiquidVestingKeeper),
 	}
 }
@@ -206,6 +206,7 @@ func simulationModules(
 		services.NewAppModule(appCodec, app.ServicesKeeper, app.AccountKeeper, app.BankKeeper),
 		operators.NewAppModule(appCodec, app.OperatorsKeeper, app.AccountKeeper, app.BankKeeper, app.StakingKeeper),
 		restaking.NewAppModule(appCodec, app.RestakingKeeper, app.AccountKeeper, app.BankKeeper, app.PoolsKeeper, app.OperatorsKeeper, app.ServicesKeeper),
+		rewards.NewAppModule(appCodec, app.RewardsKeeper, app.AccountKeeper, app.BankKeeper, app.PoolsKeeper, app.OperatorsKeeper, app.ServicesKeeper),
 	}
 }
 

testutils/simtesting/utils.go

@@ -88,6 +88,17 @@ func RandomCoin(r *rand.Rand, denom string, maxAmount int) sdk.Coin {
 	)
 }
 
+// RandomDecCoins returns a random list of DecCoins by randomly selecting
+// a sub set of the provided denoms.
+func RandomDecCoins(r *rand.Rand, denoms []string, maxAmount sdkmath.LegacyDec) sdk.DecCoins {
+	coins := sdk.NewDecCoins()
+	for _, denom := range RandomSubSlice(r, denoms) {
+		coins = coins.Add(sdk.NewDecCoinFromDec(denom, simtypes.RandomDecAmount(r, maxAmount)))
+	}
+
+	return coins
+}
+
 // RandomSubSlice returns a random subset of the given slice
 func RandomSubSlice[T any](r *rand.Rand, items []T) []T {
 	// Empty slice, we can't pick random elements
@@ -117,3 +128,26 @@ func RandomSubSlice[T any](r *rand.Rand, items []T) []T {
 
 	return elements
 }
+
+// RandomPositiveUint32 returns a random positive uint32
+func RandomPositiveUint32(r *rand.Rand) uint32 {
+	value := r.Uint32()
+	for value == 0 {
+		value = r.Uint32()
+	}
+	return value
+}
+
+// RandomPositiveUint64 returns a random positive uint64
+func RandomPositiveUint64(r *rand.Rand) uint64 {
+	value := r.Uint64()
+	for value == 0 {
+		value = r.Uint64()
+	}
+	return value
+}
+
+// RandomSliceElement returns a random element from the given slice
+func RandomSliceElement[T any](r *rand.Rand, slice []T) T {
+	return slice[r.Intn(len(slice))]
+}

utils/slices.go

@@ -57,6 +57,21 @@ func RemoveDuplicates[T comparable](slice []T) []T {
 	return result
 }
 
+// RemoveDuplicatesFunc removes all duplicate elements from the slice based
+// on the value returned by the provided function.
+func RemoveDuplicatesFunc[T any, C comparable](slice []T, compareBy func(T) C) []T {
+	seen := make(map[C]bool)
+	result := make([]T, 0, len(slice))
+	for _, v := range slice {
+		compareValue := compareBy(v)
+		if _, ok := seen[compareValue]; !ok {
+			seen[compareValue] = true
+			result = append(result, v)
+		}
+	}
+	return result
+}
+
 // Remove removes the first instance of value from the provided slice.
 func Remove[T comparable](slice []T, value T) (newSlice []T, removed bool) {
 	index := -1

x/rewards/module.go

@@ -5,28 +5,35 @@ import (
 	"encoding/json"
 	"fmt"
 
-	"github.com/grpc-ecosystem/grpc-gateway/runtime"
-	"github.com/spf13/cobra"
-
 	"cosmossdk.io/core/appmodule"
 	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/codec"
 	cdctypes "github.com/cosmos/cosmos-sdk/codec/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/module"
+	simtypes "github.com/cosmos/cosmos-sdk/types/simulation"
+	authkeeper "github.com/cosmos/cosmos-sdk/x/auth/keeper"
+	bankkeeper "github.com/cosmos/cosmos-sdk/x/bank/keeper"
+	"github.com/grpc-ecosystem/grpc-gateway/runtime"
+	"github.com/spf13/cobra"
 
+	operatorskeeper "github.com/milkyway-labs/milkyway/v3/x/operators/keeper"
+	poolskeeper "github.com/milkyway-labs/milkyway/v3/x/pools/keeper"
 	"github.com/milkyway-labs/milkyway/v3/x/rewards/client/cli"
 	"github.com/milkyway-labs/milkyway/v3/x/rewards/keeper"
+	"github.com/milkyway-labs/milkyway/v3/x/rewards/simulation"
 	"github.com/milkyway-labs/milkyway/v3/x/rewards/types"
+	serviceskeeper "github.com/milkyway-labs/milkyway/v3/x/services/keeper"
 )
 
 const (
 	consensusVersion = 1
 )
 
 var (
-	_ appmodule.AppModule   = AppModule{}
-	_ module.AppModuleBasic = AppModuleBasic{}
+	_ appmodule.AppModule        = AppModule{}
+	_ module.AppModuleBasic      = AppModuleBasic{}
+	_ module.AppModuleSimulation = AppModule{}
 )
 
 // ----------------------------------------------------------------------------
@@ -93,12 +100,32 @@ type AppModule struct {
 
 	// To ensure setting hooks properly, keeper must be a reference
 	keeper *keeper.Keeper
+
+	accountKeeper authkeeper.AccountKeeper
+	bankKeeper    bankkeeper.Keeper
+
+	poolsKeeper     *poolskeeper.Keeper
+	operatorsKeeper *operatorskeeper.Keeper
+	servicesKeeper  *serviceskeeper.Keeper
 }
 
-func NewAppModule(cdc codec.Codec, keeper *keeper.Keeper) AppModule {
+func NewAppModule(
+	cdc codec.Codec,
+	keeper *keeper.Keeper,
+	accountKeeper authkeeper.AccountKeeper,
+	bankKeeper bankkeeper.Keeper,
+	poolsKeeper *poolskeeper.Keeper,
+	operatorsKeeper *operatorskeeper.Keeper,
+	serviceKeeper *serviceskeeper.Keeper,
+) AppModule {
 	return AppModule{
-		AppModuleBasic: NewAppModuleBasic(cdc),
-		keeper:         keeper,
+		AppModuleBasic:  NewAppModuleBasic(cdc),
+		keeper:          keeper,
+		accountKeeper:   accountKeeper,
+		bankKeeper:      bankKeeper,
+		poolsKeeper:     poolsKeeper,
+		operatorsKeeper: operatorsKeeper,
+		servicesKeeper:  serviceKeeper,
 	}
 }
 
@@ -149,3 +176,35 @@ func (am AppModule) BeginBlock(ctx context.Context) error {
 func (am AppModule) IsOnePerModuleType() {}
 
 func (am AppModule) IsAppModule() {}
+
+// ----------------------------------------------------------------------------
+// AppModuleSimulation
+// ----------------------------------------------------------------------------
+
+// GenerateGenesisState creates a randomized GenState of the rewards module.
+func (AppModule) GenerateGenesisState(simState *module.SimulationState) {
+	simulation.RandomizedGenState(simState)
+}
+
+// ProposalMsgs returns msgs used for governance proposals for simulations.
+func (am AppModule) ProposalMsgs(simState module.SimulationState) []simtypes.WeightedProposalMsg {
+	return simulation.ProposalMsgs(am.bankKeeper)
+}
+
+// RegisterStoreDecoder registers a decoder for rewards module's types.
+func (am AppModule) RegisterStoreDecoder(sdr simtypes.StoreDecoderRegistry) {
+	sdr[types.StoreKey] = simtypes.NewStoreDecoderFuncFromCollectionsSchema(am.keeper.Schema)
+}
+
+// WeightedOperations returns the all the rewards module operations with their respective weights.
+func (am AppModule) WeightedOperations(simState module.SimulationState) []simtypes.WeightedOperation {
+	return simulation.WeightedOperations(
+		simState.AppParams,
+		am.accountKeeper,
+		am.bankKeeper,
+		am.poolsKeeper,
+		am.operatorsKeeper,
+		am.servicesKeeper,
+		am.keeper,
+	)
+}

x/rewards/simulation/genesis.go

@@ -0,0 +1,47 @@
+package simulation
+
+import (
+	"github.com/cosmos/cosmos-sdk/types/module"
+
+	operatorssimulation "github.com/milkyway-labs/milkyway/v3/x/operators/simulation"
+	poolssimulation "github.com/milkyway-labs/milkyway/v3/x/pools/simulation"
+	"github.com/milkyway-labs/milkyway/v3/x/rewards/types"
+	servicessimulation "github.com/milkyway-labs/milkyway/v3/x/services/simulation"
+)
+
+// RandomizedGenState generates a random GenesisState for the operators module
+func RandomizedGenState(simState *module.SimulationState) {
+	servicesGenesis := servicessimulation.GetGenesisState(simState)
+	poolsGenesis := poolssimulation.GetGenesisState(simState)
+	operatorsGenesis := operatorssimulation.GetGenesisState(simState)
+
+	rewardsPlans := RandomRewardsPlans(
+		simState.Rand,
+		poolsGenesis.Pools,
+		operatorsGenesis.Operators,
+		servicesGenesis.Services,
+		[]string{simState.BondDenom},
+	)
+	nextRewardsPlan := uint64(1)
+	for _, plan := range rewardsPlans {
+		if plan.ID >= nextRewardsPlan {
+			nextRewardsPlan = plan.ID + 1
+		}
+	}
+
+	genesis := types.NewGenesisState(
+		RandomParams(simState.Rand, []string{simState.BondDenom}),
+		nextRewardsPlan,
+		rewardsPlans,
+		nil,
+		RandomDelegatorWithdrawInfos(simState.Rand, simState.Accounts),
+		// Empty delegation type records since we need to perform side effects on
+		// other modules to have valid delegations
+		types.NewDelegationTypeRecords(nil, nil, nil, nil),
+		types.NewDelegationTypeRecords(nil, nil, nil, nil),
+		types.NewDelegationTypeRecords(nil, nil, nil, nil),
+		RandomOperatorAccumulatedCommissionRecords(simState.Rand, operatorsGenesis.Operators, []string{simState.BondDenom}),
+		RandomPoolServiceTotalDelegatorShares(simState.Rand, poolsGenesis, servicesGenesis, []string{simState.BondDenom}),
+	)
+	simState.GenState[types.ModuleName] = simState.Cdc.MustMarshalJSON(genesis)
+}