Merge PR #2930: Simulation spring cleaning

* Update PENDING.md
* Add simple period for expensive invariants
* Remove individual module simulations
* Simulate a few more blocks
* Add README explaining reason for shell scripts
* Deduplicate scripts, log exact replication command on failure
* Refactor invariants to take sdk.Context instead of baseapp.BaseApp
* Reference all issues in PENDING.md entry
* Remove no longer used simulation.RandSetup
* Bug fixes
* Address @rigelrozanski comments
* Fix typo

cmd/gaia/app/invariants.go

@@ -8,6 +8,7 @@ import (
 	distrsim "github.com/cosmos/cosmos-sdk/x/distribution/simulation"
 	"github.com/cosmos/cosmos-sdk/x/mock/simulation"
 	stakesim "github.com/cosmos/cosmos-sdk/x/stake/simulation"
+	abci "github.com/tendermint/tendermint/abci/types"
 )
 
 func (app *GaiaApp) runtimeInvariants() []simulation.Invariant {
@@ -23,8 +24,9 @@ func (app *GaiaApp) runtimeInvariants() []simulation.Invariant {
 func (app *GaiaApp) assertRuntimeInvariants() {
 	invariants := app.runtimeInvariants()
 	start := time.Now()
+	ctx := app.NewContext(false, abci.Header{Height: app.LastBlockHeight() + 1})
 	for _, inv := range invariants {
-		if err := inv(app.BaseApp); err != nil {
+		if err := inv(ctx); err != nil {
 			panic(fmt.Errorf("invariant broken: %s", err))
 		}
 	}

cmd/gaia/app/sim_test.go

@@ -40,6 +40,7 @@ var (
 	enabled   bool
 	verbose   bool
 	commit    bool
+	period    int
 )
 
 func init() {
@@ -49,6 +50,7 @@ func init() {
 	flag.BoolVar(&enabled, "SimulationEnabled", false, "Enable the simulation")
 	flag.BoolVar(&verbose, "SimulationVerbose", false, "Verbose log output")
 	flag.BoolVar(&commit, "SimulationCommit", false, "Have the simulation commit")
+	flag.IntVar(&period, "SimulationPeriod", 100, "Run slow invariants only once every period assertions")
 }
 
 func appStateFn(r *rand.Rand, accs []simulation.Account) json.RawMessage {
@@ -185,12 +187,12 @@ func testAndRunTxs(app *GaiaApp) []simulation.WeightedOperation {
 
 func invariants(app *GaiaApp) []simulation.Invariant {
 	return []simulation.Invariant{
-		banksim.NonnegativeBalanceInvariant(app.accountKeeper),
-		govsim.AllInvariants(),
-		distrsim.AllInvariants(app.distrKeeper, app.stakeKeeper),
-		stakesim.AllInvariants(app.bankKeeper, app.stakeKeeper,
-			app.feeCollectionKeeper, app.distrKeeper, app.accountKeeper),
-		slashingsim.AllInvariants(),
+		simulation.PeriodicInvariant(banksim.NonnegativeBalanceInvariant(app.accountKeeper), period, 0),
+		simulation.PeriodicInvariant(govsim.AllInvariants(), period, 0),
+		simulation.PeriodicInvariant(distrsim.AllInvariants(app.distrKeeper, app.stakeKeeper), period, 0),
+		simulation.PeriodicInvariant(stakesim.AllInvariants(app.bankKeeper, app.stakeKeeper,
+			app.feeCollectionKeeper, app.distrKeeper, app.accountKeeper), period, 0),
+		simulation.PeriodicInvariant(slashingsim.AllInvariants(), period, 0),
 	}
 }
 
@@ -219,7 +221,6 @@ func BenchmarkFullGaiaSimulation(b *testing.B) {
 	_, err := simulation.SimulateFromSeed(
 		b, app.BaseApp, appStateFn, seed,
 		testAndRunTxs(app),
-		[]simulation.RandSetup{},
 		invariants(app), // these shouldn't get ran
 		numBlocks,
 		blockSize,
@@ -262,7 +263,6 @@ func TestFullGaiaSimulation(t *testing.T) {
 	_, err := simulation.SimulateFromSeed(
 		t, app.BaseApp, appStateFn, seed,
 		testAndRunTxs(app),
-		[]simulation.RandSetup{},
 		invariants(app),
 		numBlocks,
 		blockSize,
@@ -304,7 +304,6 @@ func TestGaiaImportExport(t *testing.T) {
 	_, err := simulation.SimulateFromSeed(
 		t, app.BaseApp, appStateFn, seed,
 		testAndRunTxs(app),
-		[]simulation.RandSetup{},
 		invariants(app),
 		numBlocks,
 		blockSize,
@@ -401,7 +400,6 @@ func TestGaiaSimulationAfterImport(t *testing.T) {
 	stopEarly, err := simulation.SimulateFromSeed(
 		t, app.BaseApp, appStateFn, seed,
 		testAndRunTxs(app),
-		[]simulation.RandSetup{},
 		invariants(app),
 		numBlocks,
 		blockSize,
@@ -447,7 +445,6 @@ func TestGaiaSimulationAfterImport(t *testing.T) {
 	_, err = simulation.SimulateFromSeed(
 		t, newApp.BaseApp, appStateFn, seed,
 		testAndRunTxs(newApp),
-		[]simulation.RandSetup{},
 		invariants(newApp),
 		numBlocks,
 		blockSize,
@@ -479,13 +476,11 @@ func TestAppStateDeterminism(t *testing.T) {
 			simulation.SimulateFromSeed(
 				t, app.BaseApp, appStateFn, seed,
 				testAndRunTxs(app),
-				[]simulation.RandSetup{},
 				[]simulation.Invariant{},
 				50,
 				100,
 				true,
 			)
-			//app.Commit()
 			appHash := app.LastCommitID().Hash
 			appHashList[j] = appHash
 		}