feat(tests): add operators simulation tests (#190)

## Description

This PR adds the simulation tests for the `x/operators` module.  

Closes: MILK-37

<!-- Add a description of the changes that this PR introduces and the
files that
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---

### Author Checklist

*All items are required. Please add a note to the item if the item is
not applicable and
please add links to any relevant follow up issues.*

I have...

- [ ] included the correct [type
prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json)
in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [ ] targeted the correct branch (see [PR
Targeting](https://github.com/milkyway-labs/milkyway/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building
modules](https://docs.cosmos.network/v0.44/building-modules/intro.html)
- [ ] included the necessary unit and integration
[tests](https://github.com/milkyway-labs/milkyway/blob/master/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go
code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable
and please add
your handle next to the items reviewed if you only reviewed selected
items.*

I have...

- [ ] confirmed the correct [type
prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json)
in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

app/modules.go

@@ -155,7 +155,7 @@ func appModules(
 
 		// MilkyWay modules
 		services.NewAppModule(appCodec, app.ServicesKeeper, app.AccountKeeper, app.BankKeeper),
-		operators.NewAppModule(appCodec, app.OperatorsKeeper),
+		operators.NewAppModule(appCodec, app.OperatorsKeeper, app.AccountKeeper, app.BankKeeper, app.StakingKeeper),
 		pools.NewAppModule(appCodec, app.PoolsKeeper),
 		restaking.NewAppModule(appCodec, app.RestakingKeeper),
 		assets.NewAppModule(appCodec, app.AssetsKeeper),
@@ -210,6 +210,7 @@ func simulationModules(
 
 		// MilkyWay modules
 		services.NewAppModule(appCodec, app.ServicesKeeper, app.AccountKeeper, app.BankKeeper),
+		operators.NewAppModule(appCodec, app.OperatorsKeeper, app.AccountKeeper, app.BankKeeper, app.StakingKeeper),
 	}
 }
 

testutils/simtesting/utils.go

@@ -2,6 +2,7 @@ package simtesting
 
 import (
 	"math/rand"
+	"time"
 
 	sdkmath "cosmossdk.io/math"
 	"github.com/cosmos/cosmos-sdk/baseapp"
@@ -18,7 +19,11 @@ import (
 
 // SendMsg sends a transaction with the specified message.
 func SendMsg(
-	r *rand.Rand, moduleName string, app *baseapp.BaseApp, ak authkeeper.AccountKeeper, bk bankkeeper.Keeper,
+	r *rand.Rand,
+	moduleName string,
+	app *baseapp.BaseApp,
+	ak authkeeper.AccountKeeper,
+	bk bankkeeper.Keeper,
 	msg sdk.Msg, ctx sdk.Context,
 	simAccount simtypes.Account,
 ) (simtypes.OperationMsg, []simtypes.FutureOperation, error) {
@@ -63,6 +68,18 @@ func GetSimAccount(address sdk.Address, accs []simtypes.Account) (simtypes.Accou
 	return simtypes.Account{}, false
 }
 
+// --------------------------------------------------------------------------------------------------------------------
+
+// RandomFutureTime returns a random future time
+func RandomFutureTime(r *rand.Rand, currentTime time.Time) time.Time {
+	return currentTime.Add(time.Duration(r.Int63n(1e9)))
+}
+
+// RandomDuration returns a random duration between the min and max
+func RandomDuration(r *rand.Rand, min time.Duration, max time.Duration) time.Duration {
+	return time.Duration(r.Int63n(int64(max-min))) + min
+}
+
 // RandomCoin returns a random coin having the specified denomination and the max given amount
 func RandomCoin(r *rand.Rand, denom string, maxAmount int) sdk.Coin {
 	return sdk.NewCoin(

utils/slices.go

@@ -4,6 +4,16 @@ import (
 	"slices"
 )
 
+// Find returns the first element in the slice that satisfies the given predicate, or false if none is found.
+func Find[T any](slice []T, searchFunction func(T) bool) (*T, bool) {
+	for i, v := range slice {
+		if searchFunction(v) {
+			return &slice[i], true
+		}
+	}
+	return nil, false
+}
+
 // FindDuplicate returns the first duplicate element in the slice.
 // If no duplicates are found, it returns nil instead.
 func FindDuplicate[T comparable](slice []T) *T {

x/operators/client/cli/tx.go

@@ -58,7 +58,7 @@ func GetCmdSetOperatorParams() *cobra.Command {
 			creator := clientCtx.FromAddress.String()
 
 			// Create and validate the message
-			msg := types.NewMsgSetOperatorParams(creator, id, types.NewOperatorParams(commissionRete))
+			msg := types.NewMsgSetOperatorParams(id, types.NewOperatorParams(commissionRete), creator)
 			if err = msg.ValidateBasic(); err != nil {
 				return fmt.Errorf("message validation failed: %w", err)
 			}

x/operators/keeper/genesis.go

@@ -82,7 +82,10 @@ func (k *Keeper) InitGenesis(ctx sdk.Context, state *types.GenesisState) error {
 
 	// Store the inactivating operators
 	for _, entry := range state.UnbondingOperators {
-		k.setOperatorAsInactivating(ctx, entry.OperatorID, entry.UnbondingCompletionTime)
+		err = k.setOperatorAsInactivating(ctx, entry.OperatorID, entry.UnbondingCompletionTime)
+		if err != nil {
+			return err
+		}
 	}
 
 	// Store params

x/operators/keeper/keeper.go

@@ -19,7 +19,7 @@ type Keeper struct {
 
 	accountKeeper types.AccountKeeper
 	poolKeeper    types.CommunityPoolKeeper
-	schema        collections.Schema
+	Schema        collections.Schema
 
 	nextOperatorID     collections.Sequence                          // Next operator ID
 	operators          collections.Map[uint32, types.Operator]       // operator ID -> operator
@@ -85,7 +85,7 @@ func NewKeeper(
 	if err != nil {
 		panic(err)
 	}
-	k.schema = schema
+	k.Schema = schema
 
 	return k
 }

x/operators/keeper/msg_server_test.go

@@ -882,7 +882,6 @@ func (suite *KeeperTestSuite) TestMsgServer_DeleteOperator() {
 }
 
 func (suite *KeeperTestSuite) TestMsgServer_SetOperatorParams() {
-	testOperatorId := uint32(2)
 	operatorAdmin := "cosmos167x6ehhple8gwz5ezy9x0464jltvdpzl6qfdt4"
 
 	testCases := []struct {
@@ -895,37 +894,85 @@ func (suite *KeeperTestSuite) TestMsgServer_SetOperatorParams() {
 	}{
 		{
 			name: "set invalid params fails",
+			store: func(ctx sdk.Context) {
+				// Register a test operator
+				err := suite.k.CreateOperator(ctx, types.NewOperator(
+					1,
+					types.OPERATOR_STATUS_ACTIVE,
+					"MilkyWay Operator",
+					"https://milkyway.com",
+					"https://milkyway.com/picture",
+					operatorAdmin,
+				))
+				suite.Require().NoError(err)
+			},
 			msg: types.NewMsgSetOperatorParams(
-				operatorAdmin,
-				testOperatorId,
+				1,
 				types.NewOperatorParams(sdkmath.LegacyNewDec(-1)),
+				operatorAdmin,
 			),
 			shouldErr: true,
 		},
 		{
 			name: "not admin can't set params",
+			store: func(ctx sdk.Context) {
+				// Register a test operator
+				err := suite.k.CreateOperator(ctx, types.NewOperator(
+					1,
+					types.OPERATOR_STATUS_ACTIVE,
+					"MilkyWay Operator",
+					"https://milkyway.com",
+					"https://milkyway.com/picture",
+					operatorAdmin,
+				))
+				suite.Require().NoError(err)
+			},
 			msg: types.NewMsgSetOperatorParams(
-				"cosmos1d03wa9qd8flfjtvldndw5csv94tvg5hzfcmcgn",
-				testOperatorId,
+				1,
 				types.NewOperatorParams(sdkmath.LegacyMustNewDecFromStr("0.2")),
+				"cosmos1d03wa9qd8flfjtvldndw5csv94tvg5hzfcmcgn",
 			),
 			shouldErr: true,
 		},
 		{
 			name: "set params for not existing operator fails",
+			store: func(ctx sdk.Context) {
+				// Register a test operator
+				err := suite.k.CreateOperator(ctx, types.NewOperator(
+					1,
+					types.OPERATOR_STATUS_ACTIVE,
+					"MilkyWay Operator",
+					"https://milkyway.com",
+					"https://milkyway.com/picture",
+					operatorAdmin,
+				))
+				suite.Require().NoError(err)
+			},
 			msg: types.NewMsgSetOperatorParams(
-				operatorAdmin,
 				3,
 				types.NewOperatorParams(sdkmath.LegacyMustNewDecFromStr("0.2")),
+				operatorAdmin,
 			),
 			shouldErr: true,
 		},
 		{
 			name: "set params works properly",
+			store: func(ctx sdk.Context) {
+				// Register a test operator
+				err := suite.k.CreateOperator(ctx, types.NewOperator(
+					1,
+					types.OPERATOR_STATUS_ACTIVE,
+					"MilkyWay Operator",
+					"https://milkyway.com",
+					"https://milkyway.com/picture",
+					operatorAdmin,
+				))
+				suite.Require().NoError(err)
+			},
 			msg: types.NewMsgSetOperatorParams(
-				operatorAdmin,
-				testOperatorId,
+				1,
 				types.NewOperatorParams(sdkmath.LegacyMustNewDecFromStr("0.2")),
+				operatorAdmin,
 			),
 			expEvents: []sdk.Event{
 				sdk.NewEvent(
@@ -934,7 +981,7 @@ func (suite *KeeperTestSuite) TestMsgServer_SetOperatorParams() {
 			},
 			shouldErr: false,
 			check: func(ctx sdk.Context) {
-				params, err := suite.k.GetOperatorParams(ctx, testOperatorId)
+				params, err := suite.k.GetOperatorParams(ctx, 1)
 				suite.Require().Nil(err)
 				suite.Require().Equal(types.NewOperatorParams(
 					sdkmath.LegacyMustNewDecFromStr("0.2"),
@@ -947,23 +994,12 @@ func (suite *KeeperTestSuite) TestMsgServer_SetOperatorParams() {
 		tc := tc
 		suite.Run(tc.name, func() {
 			suite.SetupTest()
-			ctx := suite.ctx
 
+			ctx, _ := suite.ctx.CacheContext()
 			if tc.store != nil {
 				tc.store(ctx)
 			}
 
-			// Register a test operator
-			err := suite.k.CreateOperator(ctx, types.NewOperator(
-				testOperatorId,
-				types.OPERATOR_STATUS_ACTIVE,
-				"MilkyWay Operator",
-				"https://milkyway.com",
-				"https://milkyway.com/picture",
-				operatorAdmin,
-			))
-			suite.Require().NoError(err)
-
 			msgServer := keeper.NewMsgServer(suite.k)
 			res, err := msgServer.SetOperatorParams(ctx, tc.msg)
 			if tc.shouldErr {

x/operators/module.go

@@ -6,6 +6,10 @@ import (
 	"fmt"
 
 	"cosmossdk.io/core/appmodule"
+	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"
+	stakingkeeper "github.com/cosmos/cosmos-sdk/x/staking/keeper"
 	"github.com/grpc-ecosystem/grpc-gateway/runtime"
 	"github.com/spf13/cobra"
 
@@ -19,6 +23,7 @@ import (
 
 	"github.com/milkyway-labs/milkyway/x/operators/client/cli"
 	"github.com/milkyway-labs/milkyway/x/operators/keeper"
+	"github.com/milkyway-labs/milkyway/x/operators/simulation"
 	"github.com/milkyway-labs/milkyway/x/operators/types"
 )
 
@@ -27,8 +32,9 @@ const (
 )
 
 var (
-	_ appmodule.AppModule   = AppModule{}
-	_ module.AppModuleBasic = AppModuleBasic{}
+	_ appmodule.AppModule        = AppModule{}
+	_ module.AppModuleBasic      = AppModuleBasic{}
+	_ module.AppModuleSimulation = AppModule{}
 )
 
 // ----------------------------------------------------------------------------
@@ -93,14 +99,27 @@ func (a AppModuleBasic) GetTxCmd() *cobra.Command {
 type AppModule struct {
 	AppModuleBasic
 
-	// To ensure setting hooks properly, keeper must be a reference
 	keeper *keeper.Keeper
-}
 
-func NewAppModule(cdc codec.Codec, keeper *keeper.Keeper) AppModule {
+	// To ensure setting hooks properly, keeper must be a reference
+	accountKeeper authkeeper.AccountKeeper
+	bankKeeper    bankkeeper.Keeper
+	stakingKeeper *stakingkeeper.Keeper
+}
+
+func NewAppModule(
+	cdc codec.Codec,
+	keeper *keeper.Keeper,
+	accountKeeper authkeeper.AccountKeeper,
+	bankKeeper bankkeeper.Keeper,
+	stakingKeeper *stakingkeeper.Keeper,
+) AppModule {
 	return AppModule{
 		AppModuleBasic: NewAppModuleBasic(cdc),
 		keeper:         keeper,
+		accountKeeper:  accountKeeper,
+		bankKeeper:     bankKeeper,
+		stakingKeeper:  stakingKeeper,
 	}
 }
 
@@ -150,3 +169,32 @@ func (am AppModule) BeginBlock(ctx context.Context) error {
 func (am AppModule) IsOnePerModuleType() {}
 
 func (am AppModule) IsAppModule() {}
+
+// ----------------------------------------------------------------------------
+// AppModuleSimulation
+// ----------------------------------------------------------------------------
+
+// GenerateGenesisState creates a randomized GenState of the services 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.stakingKeeper)
+}
+
+// RegisterStoreDecoder registers a decoder for services module's types.
+func (am AppModule) RegisterStoreDecoder(sdr simtypes.StoreDecoderRegistry) {
+	sdr[types.StoreKey] = simulation.NewDecodeStore(am.keeper)
+}
+
+// WeightedOperations returns the all the services 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.keeper,
+	)
+}

x/operators/simulation/decoder.go

@@ -0,0 +1,37 @@
+package simulation
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/cosmos/cosmos-sdk/types/kv"
+	simtypes "github.com/cosmos/cosmos-sdk/types/simulation"
+
+	"github.com/milkyway-labs/milkyway/x/operators/keeper"
+	"github.com/milkyway-labs/milkyway/x/operators/types"
+)
+
+// NewDecodeStore returns a decoder function closure that unmarshals the KVPair's
+// Value to the corresponding operators type.
+func NewDecodeStore(keeper *keeper.Keeper) func(kvA kv.Pair, kvB kv.Pair) string {
+	collectionsDecoder := simtypes.NewStoreDecoderFuncFromCollectionsSchema(keeper.Schema)
+
+	return func(kvA, kvB kv.Pair) string {
+		switch {
+		case bytes.Equal(kvA.Key[:1], types.ParamsKey),
+			bytes.Equal(kvA.Key[:1], types.NextOperatorIDKey),
+			bytes.Equal(kvA.Key[:1], types.OperatorPrefix),
+			bytes.Equal(kvA.Key[:1], types.OperatorAddressSetPrefix),
+			bytes.Equal(kvA.Key[:1], types.OperatorParamsMapPrefix):
+			return collectionsDecoder(kvA, kvB)
+
+		case bytes.Equal(kvA.Key[:1], types.InactivatingOperatorQueuePrefix):
+			valueA := types.GetOperatorIDFromBytes(kvA.Value)
+			valueB := types.GetOperatorIDFromBytes(kvB.Value)
+			return fmt.Sprintf("operatorIDA: %d\noperatorIDB: %d", valueA, valueB)
+
+		default:
+			panic(fmt.Sprintf("invalid operators key prefix %X", kvA.Key[:1]))
+		}
+	}
+}