Work-in-progress staking invariants

x/mock/app.go

@@ -202,8 +202,7 @@ func RandomSetGenesis(r *rand.Rand, app *App, addrs []sdk.Address, denoms []stri
 		(&baseAcc).SetCoins(coins)
 		accts[i] = &baseAcc
 	}
-
-	SetGenesis(app, accts)
+	app.GenesisAccounts = accts
 }
 
 // GetAllAccounts returns all accounts in the accountMapper.

x/mock/random_simulate_blocks.go

@@ -31,11 +31,13 @@ func (app *App) RandomizedTestingFromSeed(
 	keys, addrs := GeneratePrivKeyAddressPairs(numKeys)
 	r := rand.New(rand.NewSource(seed))
 
+	RandomSetGenesis(r, app, addrs, []string{"foocoin"})
+	app.InitChain(abci.RequestInitChain{})
 	for i := 0; i < len(setups); i++ {
 		setups[i](r, keys)
 	}
+	app.Commit()
 
-	RandomSetGenesis(r, app, addrs, []string{"foocoin"})
 	header := abci.Header{Height: 0}
 
 	for i := 0; i < numBlocks; i++ {
@@ -62,6 +64,45 @@ func (app *App) RandomizedTestingFromSeed(
 	}
 }
 
+func (app *App) SimpleRandomizedTestingFromSeed(
+	t *testing.T, seed int64, ops []TestAndRunMsg, setups []RandSetup,
+	invariants []Invariant, numKeys int, numBlocks int, blockSize int,
+) {
+	log := fmt.Sprintf("Starting SimpleSingleModuleTest with randomness created with seed %d", int(seed))
+	keys, addrs := GeneratePrivKeyAddressPairs(numKeys)
+	r := rand.New(rand.NewSource(seed))
+
+	RandomSetGenesis(r, app, addrs, []string{"foocoin"})
+	app.InitChain(abci.RequestInitChain{})
+	for i := 0; i < len(setups); i++ {
+		setups[i](r, keys)
+	}
+	app.Commit()
+
+	header := abci.Header{Height: 0}
+
+	for i := 0; i < numBlocks; i++ {
+		app.BeginBlock(abci.RequestBeginBlock{})
+
+		app.assertAllInvariants(t, invariants, log)
+
+		ctx := app.NewContext(false, header)
+
+		// TODO: Add modes to simulate "no load", "medium load", and
+		// "high load" blocks.
+		for j := 0; j < blockSize; j++ {
+			logUpdate, err := ops[r.Intn(len(ops))](t, r, ctx, keys, log)
+			log += "\n" + logUpdate
+
+			require.Nil(t, err, log)
+			app.assertAllInvariants(t, invariants, log)
+		}
+
+		app.EndBlock(abci.RequestEndBlock{})
+		header.Height++
+	}
+}
+
 func (app *App) assertAllInvariants(t *testing.T, tests []Invariant, log string) {
 	for i := 0; i < len(tests); i++ {
 		tests[i](t, app, log)

x/mock/types.go

@@ -17,6 +17,15 @@ type (
 		privKeys []crypto.PrivKey, log string,
 	) (action string, err sdk.Error)
 
+	// TestAndRunMsg produces a fuzzed message, calls the appropriate handler
+	// (bypassing all ante handler checks), and ensures that the state
+	// transition was as expected. It returns a descriptive message "action"
+	// about what this fuzzed msg actually did for ease of debugging.
+	TestAndRunMsg func(
+		t *testing.T, r *rand.Rand, ctx sdk.Context,
+		privKey []crypto.PrivKey, log string,
+	) (action string, err sdk.Error)
+
 	// RandSetup performs the random setup the mock module needs.
 	RandSetup func(r *rand.Rand, privKeys []crypto.PrivKey)
 

x/stake/simulation_test.go

@@ -0,0 +1,99 @@
+package stake
+
+import (
+	// "errors"
+	"fmt"
+	"math/rand"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	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/mock"
+	abci "github.com/tendermint/tendermint/abci/types"
+	"github.com/tendermint/tendermint/crypto"
+)
+
+// ModuleInvariants runs all invariants of the stake module.
+// Currently: total supply, positive power
+func ModuleInvariants(ck bank.Keeper, k Keeper) mock.Invariant {
+	return func(t *testing.T, app *mock.App, log string) {
+		TotalSupplyInvariant(ck, k)(t, app, log)
+		PositivePowerInvariant(k)(t, app, log)
+	}
+}
+
+// TotalSupplyInvariant checks that the total supply reflects all held loose tokens, bonded tokens, and unbonding delegations
+func TotalSupplyInvariant(ck bank.Keeper, k Keeper) mock.Invariant {
+	return func(t *testing.T, app *mock.App, log string) {
+		ctx := app.NewContext(false, abci.Header{})
+		pool := k.GetPool(ctx)
+
+		// Loose tokens should equal coin supply
+		loose := sdk.ZeroInt()
+		app.AccountMapper.IterateAccounts(ctx, func(acc auth.Account) bool {
+			loose = loose.Add(acc.GetCoins().AmountOf("steak"))
+			return false
+		})
+		require.True(t, sdk.NewInt(pool.LooseTokens).Equal(loose), "expected loose tokens to equal total steak held by accounts")
+
+		// Bonded tokens should equal sum of tokens with bonded validators
+
+		// Unbonded tokens should equal sum of tokens with unbonded validators
+	}
+}
+
+// PositivePowerInvariant checks that all stored validators have > 0 power
+func PositivePowerInvariant(k Keeper) mock.Invariant {
+	return func(t *testing.T, app *mock.App, log string) {
+		ctx := app.NewContext(false, abci.Header{})
+		k.IterateValidatorsBonded(ctx, func(_ int64, validator sdk.Validator) bool {
+			require.True(t, validator.GetPower().GT(sdk.ZeroRat()), "validator with non-positive power stored")
+			return false
+		})
+	}
+}
+
+// SimulateMsgDelegate
+func SimulateMsgDelegate(k Keeper) mock.TestAndRunMsg {
+	return func(t *testing.T, r *rand.Rand, ctx sdk.Context, keys []crypto.PrivKey, log string) (action string, err sdk.Error) {
+		msg := fmt.Sprintf("TestMsgDelegate with %s", "ok")
+		return msg, nil
+	}
+}
+
+// SimulationSetup
+func SimulationSetup(mapp *mock.App, k Keeper) mock.RandSetup {
+	return func(r *rand.Rand, privKeys []crypto.PrivKey) {
+		ctx := mapp.NewContext(false, abci.Header{})
+		InitGenesis(ctx, k, DefaultGenesisState())
+	}
+}
+
+// Test random messages
+func TestStakeWithRandomMessages(t *testing.T) {
+	mapp := mock.NewApp()
+
+	bank.RegisterWire(mapp.Cdc)
+	coinKeeper := bank.NewKeeper(mapp.AccountMapper)
+	stakeKey := sdk.NewKVStoreKey("stake")
+	stakeKeeper := NewKeeper(mapp.Cdc, stakeKey, coinKeeper, DefaultCodespace)
+	mapp.Router().AddRoute("stake", NewHandler(stakeKeeper))
+
+	err := mapp.CompleteSetup([]*sdk.KVStoreKey{stakeKey})
+	if err != nil {
+		panic(err)
+	}
+
+	mapp.SimpleRandomizedTestingFromSeed(
+		t, 20, []mock.TestAndRunMsg{
+			SimulateMsgDelegate(stakeKeeper),
+		}, []mock.RandSetup{
+			SimulationSetup(mapp, stakeKeeper),
+		}, []mock.Invariant{
+			ModuleInvariants(coinKeeper, stakeKeeper),
+		}, 10, 100, 500,
+	)
+}