x/capability: simulations (#6062)

* x/capability: simulations

* update logs

* validate genesis state

* InitGenesis and ExportGenesis functions

* update validation func

* fix import-export sim

* remove nondeterminism from capability genesis

* Update x/capability/types/genesis.go

* Update x/capability/types/genesis.go

* fix tests

* fix merge

* consistency updates

* try fix nondeterminism

* fix conditional

* Fix random index logic

* lint

* lint

Co-authored-by: Aditya Sripal <adityasripal@gmail.com>
Co-authored-by: Aleksandr Bezobchuk <aleks.bezobchuk@gmail.com>
Co-authored-by: Alexander Bezobchuk <alexanderbez@users.noreply.github.com>

simapp/app.go

@@ -262,7 +262,7 @@ func NewSimApp(
 		genutil.NewAppModule(app.AccountKeeper, app.StakingKeeper, app.BaseApp.DeliverTx),
 		auth.NewAppModule(appCodec, app.AccountKeeper),
 		bank.NewAppModule(appCodec, app.BankKeeper, app.AccountKeeper),
-		capability.NewAppModule(*app.CapabilityKeeper),
+		capability.NewAppModule(appCodec, *app.CapabilityKeeper),
 		crisis.NewAppModule(&app.CrisisKeeper),
 		gov.NewAppModule(appCodec, app.GovKeeper, app.AccountKeeper, app.BankKeeper),
 		mint.NewAppModule(appCodec, app.MintKeeper, app.AccountKeeper),
@@ -307,6 +307,7 @@ func NewSimApp(
 	app.sm = module.NewSimulationManager(
 		auth.NewAppModule(appCodec, app.AccountKeeper),
 		bank.NewAppModule(appCodec, app.BankKeeper, app.AccountKeeper),
+		capability.NewAppModule(appCodec, *app.CapabilityKeeper),
 		gov.NewAppModule(appCodec, app.GovKeeper, app.AccountKeeper, app.BankKeeper),
 		mint.NewAppModule(appCodec, app.MintKeeper, app.AccountKeeper),
 		staking.NewAppModule(appCodec, app.StakingKeeper, app.AccountKeeper, app.BankKeeper),

simapp/sim_test.go

@@ -19,6 +19,7 @@ import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/x/auth"
 	"github.com/cosmos/cosmos-sdk/x/bank"
+	"github.com/cosmos/cosmos-sdk/x/capability"
 	distr "github.com/cosmos/cosmos-sdk/x/distribution"
 	"github.com/cosmos/cosmos-sdk/x/evidence"
 	"github.com/cosmos/cosmos-sdk/x/gov"
@@ -158,6 +159,7 @@ func TestAppImportExport(t *testing.T) {
 		{app.keys[paramtypes.StoreKey], newApp.keys[paramtypes.StoreKey], [][]byte{}},
 		{app.keys[gov.StoreKey], newApp.keys[gov.StoreKey], [][]byte{}},
 		{app.keys[evidence.StoreKey], newApp.keys[evidence.StoreKey], [][]byte{}},
+		{app.keys[capability.StoreKey], newApp.keys[capability.StoreKey], [][]byte{}},
 	}
 
 	for _, skp := range storeKeysPrefixes {
@@ -268,7 +270,6 @@ func TestAppStateDeterminism(t *testing.T) {
 			}
 
 			db := dbm.NewMemDB()
-
 			app := NewSimApp(logger, db, nil, true, map[int64]bool{}, DefaultNodeHome, FlagPeriodValue, interBlockCacheOpt())
 
 			fmt.Printf(
@@ -292,7 +293,7 @@ func TestAppStateDeterminism(t *testing.T) {
 
 			if j != 0 {
 				require.Equal(
-					t, appHashList[0], appHashList[j],
+					t, string(appHashList[0]), string(appHashList[j]),
 					"non-determinism in seed %d: %d/%d, attempt: %d/%d\n", config.Seed, i+1, numSeeds, j+1, numTimesToRunPerSeed,
 				)
 			}

x/capability/alias.go

@@ -37,4 +37,6 @@ type (
 	ScopedKeeper     = keeper.ScopedKeeper
 	Capability       = types.Capability
 	CapabilityOwners = types.CapabilityOwners
+	GenesisState     = types.GenesisState
+	GenesisOwners    = types.GenesisOwners
 )

x/capability/genesis.go

@@ -0,0 +1,41 @@
+package capability
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+)
+
+// InitGenesis initializes the capability module's state from a provided genesis
+// state.
+func InitGenesis(ctx sdk.Context, k Keeper, genState GenesisState) {
+	k.SetIndex(ctx, genState.Index)
+
+	// set owners for each index and initialize capability
+	for _, genOwner := range genState.Owners {
+		k.SetOwners(ctx, genOwner.Index, genOwner.Owners)
+		k.InitializeCapability(ctx, genOwner.Index, genOwner.Owners)
+	}
+}
+
+// ExportGenesis returns the capability module's exported genesis.
+func ExportGenesis(ctx sdk.Context, k Keeper) GenesisState {
+	index := k.GetLatestIndex(ctx)
+	owners := []GenesisOwners{}
+
+	for i := uint64(1); i < index; i++ {
+		capabilityOwners, ok := k.GetOwners(ctx, i)
+		if !ok || len(capabilityOwners.Owners) == 0 {
+			continue
+		}
+
+		genOwner := GenesisOwners{
+			Index:  i,
+			Owners: capabilityOwners,
+		}
+		owners = append(owners, genOwner)
+	}
+
+	return GenesisState{
+		Index:  index,
+		Owners: owners,
+	}
+}

x/capability/keeper/keeper.go

@@ -106,25 +106,10 @@ func (k *Keeper) InitializeAndSeal(ctx sdk.Context) {
 	defer iterator.Close()
 	for ; iterator.Valid(); iterator.Next() {
 		index := types.IndexFromKey(iterator.Key())
-		cap := types.NewCapability(index)
 
 		var capOwners types.CapabilityOwners
 		k.cdc.MustUnmarshalBinaryBare(iterator.Value(), &capOwners)
-
-		for _, owner := range capOwners.Owners {
-			// Set the forward mapping between the module and capability tuple and the
-			// capability name in the memKVStore
-			memStore.Set(types.FwdCapabilityKey(owner.Module, cap), []byte(owner.Name))
-
-			// Set the reverse mapping between the module and capability name and the
-			// index in the in-memory store. Since marshalling and unmarshalling into a store
-			// will change memory address of capability, we simply store index as value here
-			// and retrieve the in-memory pointer to the capability from our map
-			memStore.Set(types.RevCapabilityKey(owner.Module, owner.Name), sdk.Uint64ToBigEndian(index))
-
-			// Set the mapping from index from index to in-memory capability in the go map
-			k.capMap[index] = cap
-		}
+		k.InitializeCapability(ctx, index, capOwners)
 	}
 
 	k.sealed = true
@@ -144,6 +129,54 @@ func (k Keeper) GetLatestIndex(ctx sdk.Context) uint64 {
 	return types.IndexFromKey(store.Get(types.KeyIndex))
 }
 
+// SetOwners set the capability owners to the store
+func (k Keeper) SetOwners(ctx sdk.Context, index uint64, owners types.CapabilityOwners) {
+	prefixStore := prefix.NewStore(ctx.KVStore(k.storeKey), types.KeyPrefixIndexCapability)
+	indexKey := types.IndexToKey(index)
+
+	// set owners in persistent store
+	prefixStore.Set(indexKey, k.cdc.MustMarshalBinaryBare(&owners))
+}
+
+// GetOwners returns the capability owners with a given index.
+func (k Keeper) GetOwners(ctx sdk.Context, index uint64) (types.CapabilityOwners, bool) {
+	prefixStore := prefix.NewStore(ctx.KVStore(k.storeKey), types.KeyPrefixIndexCapability)
+	indexKey := types.IndexToKey(index)
+
+	// get owners for index from persistent store
+	ownerBytes := prefixStore.Get(indexKey)
+	if ownerBytes == nil {
+		return types.CapabilityOwners{}, false
+	}
+	var owners types.CapabilityOwners
+	k.cdc.MustUnmarshalBinaryBare(ownerBytes, &owners)
+	return owners, true
+}
+
+// InitializeCapability takes in an index and an owners array. It creates the capability in memory
+// and sets the fwd and reverse keys for each owner in the memstore
+func (k Keeper) InitializeCapability(ctx sdk.Context, index uint64, owners types.CapabilityOwners) {
+
+	memStore := ctx.KVStore(k.memKey)
+
+	cap := types.NewCapability(index)
+	for _, owner := range owners.Owners {
+		// Set the forward mapping between the module and capability tuple and the
+		// capability name in the memKVStore
+		memStore.Set(types.FwdCapabilityKey(owner.Module, cap), []byte(owner.Name))
+
+		// Set the reverse mapping between the module and capability name and the
+		// index in the in-memory store. Since marshalling and unmarshalling into a store
+		// will change memory address of capability, we simply store index as value here
+		// and retrieve the in-memory pointer to the capability from our map
+		memStore.Set(types.RevCapabilityKey(owner.Module, owner.Name), sdk.Uint64ToBigEndian(index))
+
+		// Set the mapping from index from index to in-memory capability in the go map
+		k.capMap[index] = cap
+	}
+
+}
+
 // NewCapability attempts to create a new capability with a given name. If the
 // capability already exists in the in-memory store, an error will be returned.
 // Otherwise, a new capability is created with the current global unique index.

x/capability/module.go

@@ -2,11 +2,15 @@ package capability
 
 import (
 	"encoding/json"
+	"fmt"
+	"math/rand"
 
 	"github.com/cosmos/cosmos-sdk/client/context"
 	"github.com/cosmos/cosmos-sdk/codec"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/module"
+	simtypes "github.com/cosmos/cosmos-sdk/types/simulation"
+	"github.com/cosmos/cosmos-sdk/x/capability/simulation"
 	"github.com/cosmos/cosmos-sdk/x/capability/types"
 
 	"github.com/gorilla/mux"
@@ -17,9 +21,7 @@ import (
 var (
 	_ module.AppModule           = AppModule{}
 	_ module.AppModuleBasic      = AppModuleBasic{}
-
-	// TODO: Enable simulation once concrete types are defined.
-	// _ module.AppModuleSimulation = AppModuleSimulation{}
+	_ module.AppModuleSimulation = AppModule{}
 )
 
 // ----------------------------------------------------------------------------
@@ -28,10 +30,11 @@ var (
 
 // AppModuleBasic implements the AppModuleBasic interface for the capability module.
 type AppModuleBasic struct {
+	cdc codec.Marshaler
 }
 
-func NewAppModuleBasic() AppModuleBasic {
-	return AppModuleBasic{}
+func NewAppModuleBasic(cdc codec.Marshaler) AppModuleBasic {
+	return AppModuleBasic{cdc: cdc}
 }
 
 // Name returns the capability module's name.
@@ -50,7 +53,13 @@ func (AppModuleBasic) DefaultGenesis(cdc codec.JSONMarshaler) json.RawMessage {
 }
 
 // ValidateGenesis performs genesis state validation for the capability module.
-func (AppModuleBasic) ValidateGenesis(_ codec.JSONMarshaler, _ json.RawMessage) error { return nil }
+func (AppModuleBasic) ValidateGenesis(cdc codec.JSONMarshaler, bz json.RawMessage) error {
+	var genState types.GenesisState
+	if err := cdc.UnmarshalJSON(bz, &genState); err != nil {
+		return fmt.Errorf("failed to unmarshal %s genesis state: %w", ModuleName, err)
+	}
+	return genState.Validate()
+}
 
 // RegisterRESTRoutes registers the capability module's REST service handlers.
 func (a AppModuleBasic) RegisterRESTRoutes(_ context.CLIContext, _ *mux.Router) {}
@@ -58,7 +67,7 @@ func (a AppModuleBasic) RegisterRESTRoutes(_ context.CLIContext, _ *mux.Router)
 // GetTxCmd returns the capability module's root tx command.
 func (a AppModuleBasic) GetTxCmd(_ *codec.Codec) *cobra.Command { return nil }
 
-// GetTxCmd returns the capability module's root query command.
+// GetQueryCmd returns the capability module's root query command.
 func (AppModuleBasic) GetQueryCmd(_ *codec.Codec) *cobra.Command { return nil }
 
 // ----------------------------------------------------------------------------
@@ -72,9 +81,9 @@ type AppModule struct {
 	keeper Keeper
 }
 
-func NewAppModule(keeper Keeper) AppModule {
+func NewAppModule(cdc codec.Marshaler, keeper Keeper) AppModule {
 	return AppModule{
-		AppModuleBasic: NewAppModuleBasic(),
+		AppModuleBasic: NewAppModuleBasic(cdc),
 		keeper:         keeper,
 	}
 }
@@ -102,19 +111,18 @@ func (am AppModule) RegisterInvariants(_ sdk.InvariantRegistry) {}
 // InitGenesis performs the capability module's genesis initialization It returns
 // no validator updates.
 func (am AppModule) InitGenesis(ctx sdk.Context, cdc codec.JSONMarshaler, gs json.RawMessage) []abci.ValidatorUpdate {
-	var genState types.GenesisState
+	var genState GenesisState
 	// Initialize global index to index in genesis state
 	cdc.MustUnmarshalJSON(gs, &genState)
 
-	am.keeper.SetIndex(ctx, genState.Index)
-
+	InitGenesis(ctx, am.keeper, genState)
 	return []abci.ValidatorUpdate{}
 }
 
 // ExportGenesis returns the capability module's exported genesis state as raw JSON bytes.
 func (am AppModule) ExportGenesis(ctx sdk.Context, cdc codec.JSONMarshaler) json.RawMessage {
-	index := am.keeper.GetLatestIndex(ctx)
-	return cdc.MustMarshalJSON(types.GenesisState{index})
+	genState := ExportGenesis(ctx, am.keeper)
+	return cdc.MustMarshalJSON(genState)
 }
 
 // BeginBlock executes all ABCI BeginBlock logic respective to the capability module.
@@ -125,3 +133,28 @@ func (am AppModule) BeginBlock(_ sdk.Context, _ abci.RequestBeginBlock) {}
 func (am AppModule) EndBlock(_ sdk.Context, _ abci.RequestEndBlock) []abci.ValidatorUpdate {
 	return []abci.ValidatorUpdate{}
 }
+
+// GenerateGenesisState creates a randomized GenState of the capability module.
+func (AppModule) GenerateGenesisState(simState *module.SimulationState) {
+	simulation.RandomizedGenState(simState)
+}
+
+// ProposalContents performs a no-op
+func (am AppModule) ProposalContents(simState module.SimulationState) []simtypes.WeightedProposalContent {
+	return nil
+}
+
+// RandomizedParams creates randomized capability param changes for the simulator.
+func (AppModule) RandomizedParams(r *rand.Rand) []simtypes.ParamChange {
+	return nil
+}
+
+// RegisterStoreDecoder registers a decoder for capability module's types
+func (am AppModule) RegisterStoreDecoder(sdr sdk.StoreDecoderRegistry) {
+	sdr[StoreKey] = simulation.NewDecodeStore(am.cdc)
+}
+
+// WeightedOperations returns the all the gov module operations with their respective weights.
+func (am AppModule) WeightedOperations(simState module.SimulationState) []simtypes.WeightedOperation {
+	return nil
+}

x/capability/simulation/decoder.go

@@ -0,0 +1,34 @@
+package simulation
+
+import (
+	"bytes"
+	"fmt"
+
+	tmkv "github.com/tendermint/tendermint/libs/kv"
+
+	"github.com/cosmos/cosmos-sdk/codec"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/capability/types"
+)
+
+// NewDecodeStore returns a decoder function closure that unmarshals the KVPair's
+// Value to the corresponding capaility type.
+func NewDecodeStore(cdc codec.Marshaler) func(kvA, kvB tmkv.Pair) string {
+	return func(kvA, kvB tmkv.Pair) string {
+		switch {
+		case bytes.Equal(kvA.Key, types.KeyIndex):
+			idxA := sdk.BigEndianToUint64(kvA.Value)
+			idxB := sdk.BigEndianToUint64(kvB.Value)
+			return fmt.Sprintf("Index A: %d\nIndex B: %d\n", idxA, idxB)
+
+		case bytes.HasPrefix(kvA.Key, types.KeyPrefixIndexCapability):
+			var capOwnersA, capOwnersB types.CapabilityOwners
+			cdc.MustUnmarshalBinaryBare(kvA.Value, &capOwnersA)
+			cdc.MustUnmarshalBinaryBare(kvB.Value, &capOwnersB)
+			return fmt.Sprintf("CapabilityOwners A: %v\nCapabilityOwners B: %v\n", capOwnersA, capOwnersB)
+
+		default:
+			panic(fmt.Sprintf("invalid %s key prefix %X (%s)", types.ModuleName, kvA.Key, string(kvA.Key)))
+		}
+	}
+}

x/capability/simulation/decoder_test.go

@@ -0,0 +1,59 @@
+package simulation_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	tmkv "github.com/tendermint/tendermint/libs/kv"
+
+	"github.com/cosmos/cosmos-sdk/simapp"
+	codecstd "github.com/cosmos/cosmos-sdk/std"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/capability/simulation"
+	"github.com/cosmos/cosmos-sdk/x/capability/types"
+)
+
+func TestDecodeStore(t *testing.T) {
+	cdc := codecstd.NewAppCodec(codecstd.MakeCodec(simapp.ModuleBasics))
+	dec := simulation.NewDecodeStore(cdc)
+
+	capOwners := types.CapabilityOwners{
+		Owners: []types.Owner{{Module: "transfer", Name: "ports/transfer"}},
+	}
+
+	kvPairs := tmkv.Pairs{
+		tmkv.Pair{
+			Key:   types.KeyIndex,
+			Value: sdk.Uint64ToBigEndian(10),
+		},
+		tmkv.Pair{
+			Key:   types.KeyPrefixIndexCapability,
+			Value: cdc.MustMarshalBinaryBare(&capOwners),
+		},
+		tmkv.Pair{
+			Key:   []byte{0x99},
+			Value: []byte{0x99},
+		},
+	}
+	tests := []struct {
+		name        string
+		expectedLog string
+	}{
+		{"Index", "Index A: 10\nIndex B: 10\n"},
+		{"CapabilityOwners", fmt.Sprintf("CapabilityOwners A: %v\nCapabilityOwners B: %v\n", capOwners, capOwners)},
+		{"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() { dec(kvPairs[i], kvPairs[i]) }, tt.name)
+			default:
+				require.Equal(t, tt.expectedLog, dec(kvPairs[i], kvPairs[i]), tt.name)
+			}
+		})
+	}
+}

x/capability/simulation/genesis.go

@@ -0,0 +1,36 @@
+package simulation
+
+// DONTCOVER
+
+import (
+	"fmt"
+	"math/rand"
+
+	"github.com/cosmos/cosmos-sdk/codec"
+
+	"github.com/cosmos/cosmos-sdk/types/module"
+	"github.com/cosmos/cosmos-sdk/x/capability/types"
+)
+
+// Simulation parameter constants
+const index = "index"
+
+// GenIndex returns a random global index between 1-1000
+func GenIndex(r *rand.Rand) uint64 {
+	return uint64(r.Int63n(1000)) + 1
+}
+
+// RandomizedGenState generates a random GenesisState for capability
+func RandomizedGenState(simState *module.SimulationState) {
+	var idx uint64
+
+	simState.AppParams.GetOrGenerate(
+		simState.Cdc, index, &idx, simState.Rand,
+		func(r *rand.Rand) { idx = GenIndex(r) },
+	)
+
+	capabilityGenesis := types.GenesisState{Index: idx}
+
+	fmt.Printf("Selected randomly generated %s parameters:\n%s\n", types.ModuleName, codec.MustMarshalJSONIndent(simState.Cdc, capabilityGenesis))
+	simState.GenState[types.ModuleName] = simState.Cdc.MustMarshalJSON(capabilityGenesis)
+}

x/capability/types/genesis.go

@@ -1,11 +1,65 @@
 package types
 
+import (
+	"fmt"
+	"strings"
+)
+
+// DefaultIndex is the default capability global index
+const DefaultIndex uint64 = 1
+
+// GenesisOwners defines the capability owners with their corresponding index.
+type GenesisOwners struct {
+	Index  uint64           `json:"index" yaml:"index"`
+	Owners CapabilityOwners `json:"index_owners" yaml:"index_owners"`
+}
+
 // GenesisState represents the Capability module genesis state
 type GenesisState struct {
+	// capability global index
 	Index uint64 `json:"index" yaml:"index"`
+
+	// map from index to owners of the capability index
+	// index key is string to allow amino marshalling
+	Owners []GenesisOwners `json:"owners" yaml:"owners"`
 }
 
 // DefaultGenesis returns the default Capability genesis state
 func DefaultGenesis() GenesisState {
-	return GenesisState{Index: 1}
+	return GenesisState{
+		Index:  DefaultIndex,
+		Owners: []GenesisOwners{},
+	}
+}
+
+// Validate performs basic genesis state validation returning an error upon any
+// failure.
+func (gs GenesisState) Validate() error {
+	// NOTE: index must be greater than 0
+	if gs.Index == 0 {
+		return fmt.Errorf("capability index must be non-zero")
+	}
+
+	for _, genOwner := range gs.Owners {
+		if len(genOwner.Owners.Owners) == 0 {
+			return fmt.Errorf("empty owners in genesis")
+		}
+
+		// all exported existing indices must be between [1, gs.Index)
+		if genOwner.Index == 0 || genOwner.Index >= gs.Index {
+			return fmt.Errorf("owners exist for index %d outside of valid range: %d-%d", genOwner.Index, 1, gs.Index-1)
+		}
+
+		for _, owner := range genOwner.Owners.Owners {
+			if strings.TrimSpace(owner.Module) == "" {
+				return fmt.Errorf("owner's module cannot be blank: %s", owner)
+			}
+
+			if strings.TrimSpace(owner.Name) == "" {
+				return fmt.Errorf("owner's name cannot be blank: %s", owner)
+			}
+		}
+	}
+
+	return nil
 }

x/capability/types/genesis_test.go

@@ -0,0 +1,131 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestValidateGenesis(t *testing.T) {
+	testCases := []struct {
+		name     string
+		malleate func(*GenesisState)
+		expPass  bool
+	}{
+		{
+			name:     "default",
+			malleate: func(_ *GenesisState) {},
+			expPass:  true,
+		},
+		{
+			name: "valid genesis state",
+			malleate: func(genState *GenesisState) {
+				genState.Index = 10
+				genOwner := GenesisOwners{
+					Index:  1,
+					Owners: CapabilityOwners{[]Owner{{Module: "ibc", Name: "port/transfer"}}},
+				}
+
+				genState.Owners = append(genState.Owners, genOwner)
+			},
+			expPass: true,
+		},
+		{
+			name: "initial index is 0",
+			malleate: func(genState *GenesisState) {
+				genState.Index = 0
+				genOwner := GenesisOwners{
+					Index:  0,
+					Owners: CapabilityOwners{[]Owner{{Module: "ibc", Name: "port/transfer"}}},
+				}
+
+				genState.Owners = append(genState.Owners, genOwner)
+
+			},
+			expPass: false,
+		},
+
+		{
+			name: "blank owner module",
+			malleate: func(genState *GenesisState) {
+				genState.Index = 1
+				genOwner := GenesisOwners{
+					Index:  1,
+					Owners: CapabilityOwners{[]Owner{{Module: "", Name: "port/transfer"}}},
+				}
+
+				genState.Owners = append(genState.Owners, genOwner)
+
+			},
+			expPass: false,
+		},
+		{
+			name: "blank owner name",
+			malleate: func(genState *GenesisState) {
+				genState.Index = 1
+				genOwner := GenesisOwners{
+					Index:  1,
+					Owners: CapabilityOwners{[]Owner{{Module: "ibc", Name: ""}}},
+				}
+
+				genState.Owners = append(genState.Owners, genOwner)
+
+			},
+			expPass: false,
+		},
+		{
+			name: "index above range",
+			malleate: func(genState *GenesisState) {
+				genState.Index = 10
+				genOwner := GenesisOwners{
+					Index:  12,
+					Owners: CapabilityOwners{[]Owner{{Module: "ibc", Name: "port/transfer"}}},
+				}
+
+				genState.Owners = append(genState.Owners, genOwner)
+
+			},
+			expPass: false,
+		},
+		{
+			name: "index below range",
+			malleate: func(genState *GenesisState) {
+				genState.Index = 10
+				genOwner := GenesisOwners{
+					Index:  0,
+					Owners: CapabilityOwners{[]Owner{{Module: "ibc", Name: "port/transfer"}}},
+				}
+
+				genState.Owners = append(genState.Owners, genOwner)
+
+			},
+			expPass: false,
+		},
+		{
+			name: "owners are empty",
+			malleate: func(genState *GenesisState) {
+				genState.Index = 10
+				genOwner := GenesisOwners{
+					Index:  0,
+					Owners: CapabilityOwners{[]Owner{}},
+				}
+
+				genState.Owners = append(genState.Owners, genOwner)
+
+			},
+			expPass: false,
+		},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+		genState := DefaultGenesis()
+		tc.malleate(&genState)
+		err := genState.Validate()
+		if tc.expPass {
+			require.NoError(t, err, tc.name)
+		} else {
+			require.Error(t, err, tc.name)
+		}
+	}
+}

x/ibc/20-transfer/genesis.go

@@ -9,12 +9,17 @@ import (
 
 // InitGenesis binds to portid from genesis state
 func InitGenesis(ctx sdk.Context, keeper Keeper, state types.GenesisState) {
+	// Only try to bind to port if it is not already bound, since we may already own
+	// port capability from capability InitGenesis
+	if !keeper.IsBound(ctx, state.PortID) {
 		// transfer module binds to the transfer port on InitChain
 		// and claims the returned capability
 		err := keeper.BindPort(ctx, state.PortID)
 		if err != nil {
 			panic(fmt.Sprintf("could not claim port capability: %v", err))
 		}
+	}
+
 	// check if the module account exists
 	moduleAcc := keeper.GetTransferAccount(ctx)
 	if moduleAcc == nil {

x/ibc/20-transfer/keeper/keeper.go

@@ -94,6 +94,12 @@ func (k Keeper) ChanCloseInit(ctx sdk.Context, portID, channelID string) error {
 	return k.channelKeeper.ChanCloseInit(ctx, portID, channelID, chanCap)
 }
 
+// IsBound checks if the transfer module is already bound to the desired port
+func (k Keeper) IsBound(ctx sdk.Context, portID string) bool {
+	_, ok := k.scopedKeeper.GetCapability(ctx, porttypes.PortPath(portID))
+	return ok
+}
+
 // BindPort defines a wrapper function for the ort Keeper's function in
 // order to expose it to module's InitGenesis function
 func (k Keeper) BindPort(ctx sdk.Context, portID string) error {