application interfaces for simulation

simapp/app.go

@@ -11,6 +11,7 @@ import (
 
 	bam "github.com/cosmos/cosmos-sdk/baseapp"
 	"github.com/cosmos/cosmos-sdk/codec"
+	"github.com/cosmos/cosmos-sdk/simapp/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/module"
 	"github.com/cosmos/cosmos-sdk/version"
@@ -84,6 +85,12 @@ func MakeCodec() *codec.Codec {
 	return cdc
 }
 
+// Verify app interfaces at compile time
+var (
+	_ types.App           = (*SimApp)(nil)
+	_ types.SimulationApp = (*SimApp)(nil)
+)
+
 // SimApp extends an ABCI application, but with most of its parameters exported.
 // They are exported for convenience in creating helper functions, as object
 // capabilities aren't needed for testing.
@@ -290,6 +297,12 @@ func NewSimApp(
 	return app
 }
 
+// Name returns the name of the App
+func (app *SimApp) Name() string { return app.BaseApp.Name() }
+
+// GetBaseApp returns the application's BaseApp
+func (app *SimApp) GetBaseApp() *bam.BaseApp { return app.BaseApp }
+
 // BeginBlocker application updates every begin block
 func (app *SimApp) BeginBlocker(ctx sdk.Context, req abci.RequestBeginBlock) abci.ResponseBeginBlock {
 	return app.mm.BeginBlock(ctx, req)
@@ -351,6 +364,11 @@ func (app *SimApp) GetSubspace(moduleName string) params.Subspace {
 	return app.subspaces[moduleName]
 }
 
+// SimulationManager implements the SimulationApp interface
+func (app *SimApp) SimulationManager() *module.SimulationManager {
+	return app.sm
+}
+
 // GetMaccPerms returns a copy of the module account permissions
 func GetMaccPerms() map[string][]string {
 	dupMaccPerms := make(map[string][]string)

simapp/app_test.go

@@ -18,7 +18,7 @@ func TestSimAppExport(t *testing.T) {
 	app := NewSimApp(log.NewTMLogger(log.NewSyncWriter(os.Stdout)), db, nil, true, 0)
 
 	genesisState := NewDefaultGenesisState()
-	stateBytes, err := codec.MarshalJSONIndent(app.cdc, genesisState)
+	stateBytes, err := codec.MarshalJSONIndent(app.Codec(), genesisState)
 	require.NoError(t, err)
 
 	// Initialize the chain

simapp/params.go → simapp/params/params.go

@@ -1,4 +1,4 @@
-package simapp
+package params
 
 // Simulation parameter constants
 const (

simapp/sim_bench_test.go

@@ -35,7 +35,7 @@ func BenchmarkFullAppSimulation(b *testing.B) {
 	// Run randomized simulation
 	// TODO: parameterize numbers, save for a later PR
 	_, simParams, simErr := simulation.SimulateFromSeed(
-		b, os.Stdout, app.BaseApp, AppStateFn(app.Codec(), app.sm),
+		b, os.Stdout, app.GetBaseApp(), AppStateFn(app.Codec(), app.SimulationManager()),
 		SimulationOperations(app, app.Codec(), config),
 		app.ModuleAccountAddrs(), config,
 	)
@@ -86,7 +86,7 @@ func BenchmarkInvariants(b *testing.B) {
 
 	// 2. Run parameterized simulation (w/o invariants)
 	_, simParams, simErr := simulation.SimulateFromSeed(
-		b, ioutil.Discard, app.BaseApp, AppStateFn(app.Codec(), app.sm),
+		b, ioutil.Discard, app.GetBaseApp(), AppStateFn(app.Codec(), app.SimulationManager()),
 		SimulationOperations(app, app.Codec(), config),
 		app.ModuleAccountAddrs(), config,
 	)

simapp/sim_test.go

@@ -74,7 +74,7 @@ func TestFullAppSimulation(t *testing.T) {
 
 	// Run randomized simulation
 	_, simParams, simErr := simulation.SimulateFromSeed(
-		t, os.Stdout, app.BaseApp, AppStateFn(app.Codec(), app.sm),
+		t, os.Stdout, app.GetBaseApp(), AppStateFn(app.Codec(), app.SimulationManager()),
 		SimulationOperations(app, app.Codec(), config),
 		app.ModuleAccountAddrs(), config,
 	)
@@ -130,7 +130,7 @@ func TestAppImportExport(t *testing.T) {
 
 	// Run randomized simulation
 	_, simParams, simErr := simulation.SimulateFromSeed(
-		t, os.Stdout, app.BaseApp, AppStateFn(app.Codec(), app.sm),
+		t, os.Stdout, app.GetBaseApp(), AppStateFn(app.Codec(), app.SimulationManager()),
 		SimulationOperations(app, app.Codec(), config),
 		app.ModuleAccountAddrs(), config,
 	)
@@ -174,7 +174,7 @@ func TestAppImportExport(t *testing.T) {
 	require.Equal(t, "SimApp", newApp.Name())
 
 	var genesisState GenesisState
-	err = app.cdc.UnmarshalJSON(appState, &genesisState)
+	err = app.Codec().UnmarshalJSON(appState, &genesisState)
 	require.NoError(t, err)
 
 	ctxB := newApp.NewContext(true, abci.Header{Height: app.LastBlockHeight()})
@@ -216,7 +216,7 @@ func TestAppImportExport(t *testing.T) {
 		require.Equal(t, len(failedKVAs), len(failedKVBs), "unequal sets of key-values to compare")
 
 		fmt.Printf("compared %d key/value pairs between %s and %s\n", len(failedKVAs), storeKeyA, storeKeyB)
-		require.Equal(t, len(failedKVAs), 0, GetSimulationLog(storeKeyA.Name(), app.sm.StoreDecoders, app.cdc, failedKVAs, failedKVBs))
+		require.Equal(t, len(failedKVAs), 0, GetSimulationLog(storeKeyA.Name(), app.SimulationManager().StoreDecoders, app.Codec(), failedKVAs, failedKVBs))
 	}
 }
 
@@ -248,7 +248,7 @@ func TestAppSimulationAfterImport(t *testing.T) {
 
 	// Run randomized simulation
 	stopEarly, simParams, simErr := simulation.SimulateFromSeed(
-		t, os.Stdout, app.BaseApp, AppStateFn(app.Codec(), app.sm),
+		t, os.Stdout, app.GetBaseApp(), AppStateFn(app.Codec(), app.SimulationManager()),
 		SimulationOperations(app, app.Codec(), config),
 		app.ModuleAccountAddrs(), config,
 	)
@@ -304,7 +304,7 @@ func TestAppSimulationAfterImport(t *testing.T) {
 
 	// Run randomized simulation on imported app
 	_, _, err = simulation.SimulateFromSeed(
-		t, os.Stdout, newApp.BaseApp, AppStateFn(app.Codec(), app.sm),
+		t, os.Stdout, newApp.GetBaseApp(), AppStateFn(app.Codec(), app.SimulationManager()),
 		SimulationOperations(newApp, newApp.Codec(), config),
 		newApp.ModuleAccountAddrs(), config,
 	)
@@ -351,7 +351,7 @@ func TestAppStateDeterminism(t *testing.T) {
 			)
 
 			_, _, err := simulation.SimulateFromSeed(
-				t, os.Stdout, app.BaseApp, AppStateFn(app.Codec(), app.sm),
+				t, os.Stdout, app.GetBaseApp(), AppStateFn(app.Codec(), app.SimulationManager()),
 				SimulationOperations(app, app.Codec(), config),
 				app.ModuleAccountAddrs(), config,
 			)

simapp/state.go

@@ -12,6 +12,7 @@ import (
 	tmtypes "github.com/tendermint/tendermint/types"
 
 	"github.com/cosmos/cosmos-sdk/codec"
+	simapparams "github.com/cosmos/cosmos-sdk/simapp/params"
 	"github.com/cosmos/cosmos-sdk/types/module"
 	"github.com/cosmos/cosmos-sdk/x/auth"
 	"github.com/cosmos/cosmos-sdk/x/simulation"
@@ -80,11 +81,11 @@ func AppStateRandomizedFn(
 	// number of bonded accounts
 	var initialStake, numInitiallyBonded int64
 	appParams.GetOrGenerate(
-		cdc, StakePerAccount, &initialStake, r,
+		cdc, simapparams.StakePerAccount, &initialStake, r,
 		func(r *rand.Rand) { initialStake = int64(r.Intn(1e12)) },
 	)
 	appParams.GetOrGenerate(
-		cdc, InitiallyBondedValidators, &numInitiallyBonded, r,
+		cdc, simapparams.InitiallyBondedValidators, &numInitiallyBonded, r,
 		func(r *rand.Rand) { numInitiallyBonded = int64(r.Intn(300)) },
 	)
 

simapp/test_helpers.go

@@ -27,7 +27,7 @@ func Setup(isCheckTx bool) *SimApp {
 	if !isCheckTx {
 		// init chain must be called to stop deliverState from being nil
 		genesisState := NewDefaultGenesisState()
-		stateBytes, err := codec.MarshalJSONIndent(app.cdc, genesisState)
+		stateBytes, err := codec.MarshalJSONIndent(app.Codec(), genesisState)
 		if err != nil {
 			panic(err)
 		}
@@ -54,10 +54,10 @@ func SetupWithGenesisAccounts(genAccs []authexported.GenesisAccount) *SimApp {
 	genesisState := NewDefaultGenesisState()
 
 	authGenesis := auth.NewGenesisState(auth.DefaultParams(), genAccs)
-	genesisStateBz := app.cdc.MustMarshalJSON(authGenesis)
+	genesisStateBz := app.Codec().MustMarshalJSON(authGenesis)
 	genesisState[auth.ModuleName] = genesisStateBz
 
-	stateBytes, err := codec.MarshalJSONIndent(app.cdc, genesisState)
+	stateBytes, err := codec.MarshalJSONIndent(app.Codec(), genesisState)
 	if err != nil {
 		panic(err)
 	}
@@ -102,7 +102,7 @@ func AddTestAddrs(app *SimApp, ctx sdk.Context, accNum int, accAmt sdk.Int) []sd
 
 // CheckBalance checks the balance of an account.
 func CheckBalance(t *testing.T, app *SimApp, addr sdk.AccAddress, exp sdk.Coins) {
-	ctxCheck := app.BaseApp.NewContext(true, abci.Header{})
+	ctxCheck := app.GetBaseApp().NewContext(true, abci.Header{})
 	res := app.AccountKeeper.GetAccount(ctxCheck, addr)
 
 	require.Equal(t, exp, res.GetCoins())

simapp/types/types.go

@@ -0,0 +1,49 @@
+/*
+Package types defines the interfaces required for an SDK-based app. In particular
+it defines two interfaces: `App`, for common methods and `SimulationApp` for
+apps that implement the SDK simulator.
+*/
+package types
+
+import (
+	"encoding/json"
+
+	abci "github.com/tendermint/tendermint/abci/types"
+	tmtypes "github.com/tendermint/tendermint/types"
+
+	"github.com/cosmos/cosmos-sdk/baseapp"
+	"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/params"
+)
+
+type (
+	// App implements the common methods for a Cosmos SDK-based application
+	// specific blockchain.
+	App interface {
+		GetBaseApp() *baseapp.BaseApp
+
+		Name() string
+		Codec() *codec.Codec
+		GetKey(storeKey string) *sdk.KVStoreKey
+		GetTKey(storeKey string) *sdk.TransientStoreKey
+		GetSubspace(moduleName string) params.Subspace
+
+		BeginBlocker(ctx sdk.Context, req abci.RequestBeginBlock) abci.ResponseBeginBlock
+		EndBlocker(ctx sdk.Context, req abci.RequestEndBlock) abci.ResponseEndBlock
+		InitChainer(ctx sdk.Context, req abci.RequestInitChain) abci.ResponseInitChain
+		LoadHeight(height int64) error
+
+		ExportAppStateAndValidators(
+			forZeroHeight bool, jailWhiteList []string,
+		) (json.RawMessage, []tmtypes.GenesisValidator, error)
+	}
+
+	// SimulationApp exposes all the methods that an SDK app needs to implement to
+	// use the blockchain simulator.
+	SimulationApp interface {
+		Codec() *codec.Codec
+		SimulationManager() *module.SimulationManager
+	}
+)

simapp/utils.go

@@ -9,6 +9,7 @@ import (
 	cmn "github.com/tendermint/tendermint/libs/common"
 
 	"github.com/cosmos/cosmos-sdk/codec"
+	"github.com/cosmos/cosmos-sdk/simapp/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/module"
 	"github.com/cosmos/cosmos-sdk/x/simulation"
@@ -87,7 +88,7 @@ func NewConfigFromFlags() simulation.Config {
 
 // SimulationOperations retrieves the simulation params from the provided file path
 // and returns all the modules weighted operations
-func SimulationOperations(app *SimApp, cdc *codec.Codec, config simulation.Config) []simulation.WeightedOperation {
+func SimulationOperations(app types.SimulationApp, cdc *codec.Codec, config simulation.Config) []simulation.WeightedOperation {
 	simState := module.SimulationState{
 		AppParams: make(simulation.AppParams),
 		Cdc:       cdc,
@@ -99,19 +100,19 @@ func SimulationOperations(app *SimApp, cdc *codec.Codec, config simulation.Confi
 			panic(err)
 		}
 
-		app.cdc.MustUnmarshalJSON(bz, &simState.AppParams)
+		app.Codec().MustUnmarshalJSON(bz, &simState.AppParams)
 	}
 
-	simState.ParamChanges = app.sm.GenerateParamChanges(config.Seed)
-	simState.Contents = app.sm.GetProposalContents(simState)
-	return app.sm.WeightedOperations(simState)
+	simState.ParamChanges = app.SimulationManager().GenerateParamChanges(config.Seed)
+	simState.Contents = app.SimulationManager().GetProposalContents(simState)
+	return app.SimulationManager().WeightedOperations(simState)
 }
 
 //---------------------------------------------------------------------
 // Simulation Utils
 
 // ExportStateToJSON util function to export the app state to JSON
-func ExportStateToJSON(app *SimApp, path string) error {
+func ExportStateToJSON(app types.App, path string) error {
 	fmt.Println("exporting app state...")
 	appState, _, err := app.ExportAppStateAndValidators(false, nil)
 	if err != nil {