refactor!: extract `AppStateFn` out of simapp (backport #14977) (#14978)

Co-authored-by: Julien Robert <julien@rbrt.fr>

CHANGELOG.md

@@ -39,6 +39,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+* (simapp) [#14977](https://github.com/cosmos/cosmos-sdk/pull/14977) Move simulation helpers functions (`AppStateFn` and `AppStateRandomizedFn`) to `testutil/sims`. These takes an extra genesisState argument which is the default state of the app.
 * (cli) [#14953](https://github.com/cosmos/cosmos-sdk/pull/14953) Enable profiling block replay during abci handshake with `--cpu-profile`.
 * (store) [#14410](https://github.com/cosmos/cosmos-sdk/pull/14410) `rootmulti.Store.loadVersion` has validation to check if all the module stores' height is correct, it will error if any module store has incorrect height.
 * (store) [#14189](https://github.com/cosmos/cosmos-sdk/pull/14189) Add config `iavl-lazy-loading` to enable lazy loading of iavl store, to improve start up time of archive nodes, add method `SetLazyLoading` to `CommitMultiStore` interface.

simapp/params/params.go

@@ -1,7 +0,0 @@
-package params
-
-// Simulation parameter constants
-const (
-	StakePerAccount           = "stake_per_account"
-	InitiallyBondedValidators = "initially_bonded_validators"
-)

simapp/sim_bench_test.go

@@ -49,7 +49,7 @@ func BenchmarkFullAppSimulation(b *testing.B) {
 		b,
 		os.Stdout,
 		app.BaseApp,
-		AppStateFn(app.AppCodec(), app.SimulationManager()),
+		simtestutil.AppStateFn(app.AppCodec(), app.SimulationManager(), app.DefaultGenesis()),
 		simtypes.RandomAccounts, // Replace with own random account function if using keys other than secp256k1
 		simtestutil.SimulationOperations(app, app.AppCodec(), config),
 		BlockedAddresses(),
@@ -104,7 +104,7 @@ func BenchmarkInvariants(b *testing.B) {
 		b,
 		os.Stdout,
 		app.BaseApp,
-		AppStateFn(app.AppCodec(), app.SimulationManager()),
+		simtestutil.AppStateFn(app.AppCodec(), app.SimulationManager(), app.DefaultGenesis()),
 		simtypes.RandomAccounts, // Replace with own random account function if using keys other than secp256k1
 		simtestutil.SimulationOperations(app, app.AppCodec(), config),
 		BlockedAddresses(),

simapp/sim_test.go

@@ -92,7 +92,7 @@ func TestFullAppSimulation(t *testing.T) {
 		t,
 		os.Stdout,
 		app.BaseApp,
-		AppStateFn(app.AppCodec(), app.SimulationManager()),
+		simtestutil.AppStateFn(app.AppCodec(), app.SimulationManager(), app.DefaultGenesis()),
 		simtypes.RandomAccounts, // Replace with own random account function if using keys other than secp256k1
 		simtestutil.SimulationOperations(app, app.AppCodec(), config),
 		BlockedAddresses(),
@@ -137,7 +137,7 @@ func TestAppImportExport(t *testing.T) {
 		t,
 		os.Stdout,
 		app.BaseApp,
-		AppStateFn(app.AppCodec(), app.SimulationManager()),
+		simtestutil.AppStateFn(app.AppCodec(), app.SimulationManager(), app.DefaultGenesis()),
 		simtypes.RandomAccounts, // Replace with own random account function if using keys other than secp256k1
 		simtestutil.SimulationOperations(app, app.AppCodec(), config),
 		BlockedAddresses(),
@@ -253,7 +253,7 @@ func TestAppSimulationAfterImport(t *testing.T) {
 		t,
 		os.Stdout,
 		app.BaseApp,
-		AppStateFn(app.AppCodec(), app.SimulationManager()),
+		simtestutil.AppStateFn(app.AppCodec(), app.SimulationManager(), app.DefaultGenesis()),
 		simtypes.RandomAccounts, // Replace with own random account function if using keys other than secp256k1
 		simtestutil.SimulationOperations(app, app.AppCodec(), config),
 		BlockedAddresses(),
@@ -301,7 +301,7 @@ func TestAppSimulationAfterImport(t *testing.T) {
 		t,
 		os.Stdout,
 		newApp.BaseApp,
-		AppStateFn(app.AppCodec(), app.SimulationManager()),
+		simtestutil.AppStateFn(app.AppCodec(), app.SimulationManager(), app.DefaultGenesis()),
 		simtypes.RandomAccounts, // Replace with own random account function if using keys other than secp256k1
 		simtestutil.SimulationOperations(newApp, newApp.AppCodec(), config),
 		BlockedAddresses(),
@@ -356,7 +356,7 @@ func TestAppStateDeterminism(t *testing.T) {
 				t,
 				os.Stdout,
 				app.BaseApp,
-				AppStateFn(app.AppCodec(), app.SimulationManager()),
+				simtestutil.AppStateFn(app.AppCodec(), app.SimulationManager(), app.DefaultGenesis()),
 				simtypes.RandomAccounts, // Replace with own random account function if using keys other than secp256k1
 				simtestutil.SimulationOperations(app, app.AppCodec(), config),
 				BlockedAddresses(),

testutil/sims/state_helpers.go

@@ -1,4 +1,4 @@
-package simapp
+package sims
 
 import (
 	"encoding/json"
@@ -8,11 +8,10 @@ import (
 	"os"
 	"time"
 
+	"cosmossdk.io/math"
 	tmjson "github.com/tendermint/tendermint/libs/json"
 	tmtypes "github.com/tendermint/tendermint/types"
 
-	"cosmossdk.io/math"
-	simappparams "cosmossdk.io/simapp/params"
 	"github.com/cosmos/cosmos-sdk/codec"
 	"github.com/cosmos/cosmos-sdk/crypto/keys/secp256k1"
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -24,11 +23,21 @@ import (
 	stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
 )
 
+// Simulation parameter constants
+const (
+	StakePerAccount           = "stake_per_account"
+	InitiallyBondedValidators = "initially_bonded_validators"
+)
+
 // AppStateFn returns the initial application state using a genesis or the simulation parameters.
 // It panics if the user provides files for both of them.
 // If a file is not given for the genesis or the sim params, it creates a randomized one.
-func AppStateFn(cdc codec.JSONCodec, simManager *module.SimulationManager) simtypes.AppStateFn {
+// genesisState is the default genesis state of the whole app.
-	return func(r *rand.Rand, accs []simtypes.Account, config simtypes.Config,
+func AppStateFn(cdc codec.JSONCodec, simManager *module.SimulationManager, genesisState map[string]json.RawMessage) simtypes.AppStateFn {
+	return func(
+		r *rand.Rand,
+		accs []simtypes.Account,
+		config simtypes.Config,
 	) (appState json.RawMessage, simAccs []simtypes.Account, chainID string, genesisTimestamp time.Time) {
 		if simcli.FlagGenesisTimeValue == 0 {
 			genesisTimestamp = simtypes.RandTimestamp(r)
@@ -43,7 +52,10 @@ func AppStateFn(cdc codec.JSONCodec, simManager *module.SimulationManager) simty
 
 		case config.GenesisFile != "":
 			// override the default chain-id from simapp to set it later to the config
-			genesisDoc, accounts := AppStateFromGenesisFileFn(r, cdc, config.GenesisFile)
+			genesisDoc, accounts, err := AppStateFromGenesisFileFn(r, cdc, config.GenesisFile)
+			if err != nil {
+				panic(err)
+			}
 
 			if simcli.FlagGenesisTimeValue == 0 {
 				// use genesis timestamp if no custom timestamp is provided (i.e no random timestamp)
@@ -65,11 +77,11 @@ func AppStateFn(cdc codec.JSONCodec, simManager *module.SimulationManager) simty
 			if err != nil {
 				panic(err)
 			}
-			appState, simAccs = AppStateRandomizedFn(simManager, r, cdc, accs, genesisTimestamp, appParams)
+			appState, simAccs = AppStateRandomizedFn(simManager, r, cdc, accs, genesisTimestamp, appParams, genesisState)
 
 		default:
 			appParams := make(simtypes.AppParams)
-			appState, simAccs = AppStateRandomizedFn(simManager, r, cdc, accs, genesisTimestamp, appParams)
+			appState, simAccs = AppStateRandomizedFn(simManager, r, cdc, accs, genesisTimestamp, appParams, genesisState)
 		}
 
 		rawState := make(map[string]json.RawMessage)
@@ -84,8 +96,7 @@ func AppStateFn(cdc codec.JSONCodec, simManager *module.SimulationManager) simty
 		}
 
 		stakingState := new(stakingtypes.GenesisState)
-		err = cdc.UnmarshalJSON(stakingStateBz, stakingState)
+		if err = cdc.UnmarshalJSON(stakingStateBz, stakingState); err != nil {
-		if err != nil {
 			panic(err)
 		}
 		// compute not bonded balance
@@ -104,8 +115,7 @@ func AppStateFn(cdc codec.JSONCodec, simManager *module.SimulationManager) simty
 			panic("bank genesis state is missing")
 		}
 		bankState := new(banktypes.GenesisState)
-		err = cdc.UnmarshalJSON(bankStateBz, bankState)
+		if err = cdc.UnmarshalJSON(bankStateBz, bankState); err != nil {
-		if err != nil {
 			panic(err)
 		}
 
@@ -140,12 +150,15 @@ func AppStateFn(cdc codec.JSONCodec, simManager *module.SimulationManager) simty
 // AppStateRandomizedFn creates calls each module's GenesisState generator function
 // and creates the simulation params
 func AppStateRandomizedFn(
-	simManager *module.SimulationManager, r *rand.Rand, cdc codec.JSONCodec,
+	simManager *module.SimulationManager,
-	accs []simtypes.Account, genesisTimestamp time.Time, appParams simtypes.AppParams,
+	r *rand.Rand,
+	cdc codec.JSONCodec,
+	accs []simtypes.Account,
+	genesisTimestamp time.Time,
+	appParams simtypes.AppParams,
+	genesisState map[string]json.RawMessage,
 ) (json.RawMessage, []simtypes.Account) {
 	numAccs := int64(len(accs))
-	genesisState := ModuleBasics.DefaultGenesis(cdc)
-
 	// generate a random amount of initial stake coins and a random initial
 	// number of bonded accounts
 	var (
@@ -153,11 +166,11 @@ func AppStateRandomizedFn(
 		initialStake       math.Int
 	)
 	appParams.GetOrGenerate(
-		cdc, simappparams.StakePerAccount, &initialStake, r,
+		cdc, StakePerAccount, &initialStake, r,
 		func(r *rand.Rand) { initialStake = math.NewInt(r.Int63n(1e12)) },
 	)
 	appParams.GetOrGenerate(
-		cdc, simappparams.InitiallyBondedValidators, &numInitiallyBonded, r,
+		cdc, InitiallyBondedValidators, &numInitiallyBonded, r,
 		func(r *rand.Rand) { numInitiallyBonded = int64(r.Intn(300)) },
 	)
 
@@ -197,7 +210,7 @@ func AppStateRandomizedFn(
 
 // AppStateFromGenesisFileFn util function to generate the genesis AppState
 // from a genesis.json file.
-func AppStateFromGenesisFileFn(r io.Reader, cdc codec.JSONCodec, genesisFile string) (tmtypes.GenesisDoc, []simtypes.Account) {
+func AppStateFromGenesisFileFn(r io.Reader, cdc codec.JSONCodec, genesisFile string) (tmtypes.GenesisDoc, []simtypes.Account, error) {
 	bytes, err := os.ReadFile(genesisFile)
 	if err != nil {
 		panic(err)
@@ -207,13 +220,12 @@ func AppStateFromGenesisFileFn(r io.Reader, cdc codec.JSONCodec, genesisFile str
 	// NOTE: Tendermint uses a custom JSON decoder for GenesisDoc
 	err = tmjson.Unmarshal(bytes, &genesis)
 	if err != nil {
-		panic(err)
+		return genesis, nil, err
 	}
 
-	var appState GenesisState
+	var appState map[string]json.RawMessage
-	err = json.Unmarshal(genesis.AppState, &appState)
+	if err = json.Unmarshal(genesis.AppState, &appState); err != nil {
-	if err != nil {
+		return genesis, nil, err
-		panic(err)
 	}
 
 	var authGenesis authtypes.GenesisState
@@ -235,7 +247,7 @@ func AppStateFromGenesisFileFn(r io.Reader, cdc codec.JSONCodec, genesisFile str
 
 		a, ok := acc.GetCachedValue().(authtypes.AccountI)
 		if !ok {
-			panic("expected account")
+			return genesis, nil, fmt.Errorf("expected account")
 		}
 
 		// create simulator accounts
@@ -243,5 +255,5 @@ func AppStateFromGenesisFileFn(r io.Reader, cdc codec.JSONCodec, genesisFile str
 		newAccs[i] = simAcc
 	}
 
-	return genesis, newAccs
+	return genesis, newAccs, nil
 }