Connect coin handler to a store and test it

modules/coin/handler.go

@@ -29,12 +29,18 @@ func (_ Handler) Name() string {
 
 // CheckTx checks if there is enough money in the account
 func (h Handler) CheckTx(ctx basecoin.Context, store types.KVStore, tx basecoin.Tx) (res basecoin.Result, err error) {
-	_, err = checkTx(ctx, tx)
+	send, err := checkTx(ctx, tx)
 	if err != nil {
 		return res, err
 	}
 
 	// now make sure there is money
+	for _, in := range send.Inputs {
+		_, err = h.CheckCoins(store, in.Address, in.Coins, in.Sequence)
+		if err != nil {
+			return res, err
+		}
+	}
 
 	// otherwise, we are good
 	return res, nil
@@ -42,12 +48,29 @@ func (h Handler) CheckTx(ctx basecoin.Context, store types.KVStore, tx basecoin.
 
 // DeliverTx moves the money
 func (h Handler) DeliverTx(ctx basecoin.Context, store types.KVStore, tx basecoin.Tx) (res basecoin.Result, err error) {
-	_, err = checkTx(ctx, tx)
+	send, err := checkTx(ctx, tx)
 	if err != nil {
 		return res, err
 	}
 
-	// now move the money
+	// deduct from all input accounts
+	for _, in := range send.Inputs {
+		_, err = h.ChangeCoins(store, in.Address, in.Coins.Negative(), in.Sequence)
+		if err != nil {
+			return res, err
+		}
+	}
+
+	// add to all output accounts
+	for _, out := range send.Outputs {
+		// note: sequence number is ignored when adding coins, only checked for subtracting
+		_, err = h.ChangeCoins(store, out.Address, out.Coins, 0)
+		if err != nil {
+			return res, err
+		}
+	}
+
+	// a-ok!
 	return basecoin.Result{}, nil
 }
 

modules/coin/handler_test.go

@@ -4,72 +4,159 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"github.com/tendermint/basecoin"
 	"github.com/tendermint/basecoin/stack"
 	"github.com/tendermint/basecoin/types"
 )
 
-func TestHandlerPermissions(t *testing.T) {
+// this makes sure that txs are rejected with invalid data or permissions
+func TestHandlerValidation(t *testing.T) {
 	assert := assert.New(t)
-	// TODO: need to update this when we actually have token store
-	h := NewHandler()
 
 	// these are all valid, except for minusCoins
 	addr1 := basecoin.Actor{App: "coin", Address: []byte{1, 2}}
 	addr2 := basecoin.Actor{App: "role", Address: []byte{7, 8}}
 	someCoins := types.Coins{{"atom", 123}}
+	doubleCoins := types.Coins{{"atom", 246}}
 	minusCoins := types.Coins{{"eth", -34}}
 
 	cases := []struct {
 		valid bool
-		tx    SendTx
+		tx    basecoin.Tx
 		perms []basecoin.Actor
 	}{
 		// auth works with different apps
 		{true,
-			SendTx{
-				Inputs:  []TxInput{NewTxInput(addr1, someCoins, 2)},
-				Outputs: []TxOutput{NewTxOutput(addr2, someCoins)}},
+			NewSendTx(
+				[]TxInput{NewTxInput(addr1, someCoins, 2)},
+				[]TxOutput{NewTxOutput(addr2, someCoins)}),
 			[]basecoin.Actor{addr1}},
 		{true,
-			SendTx{
-				Inputs:  []TxInput{NewTxInput(addr2, someCoins, 2)},
-				Outputs: []TxOutput{NewTxOutput(addr1, someCoins)}},
+			NewSendTx(
+				[]TxInput{NewTxInput(addr2, someCoins, 2)},
+				[]TxOutput{NewTxOutput(addr1, someCoins)}),
+			[]basecoin.Actor{addr1, addr2}},
+		// check multi-input with both sigs
+		{true,
+			NewSendTx(
+				[]TxInput{NewTxInput(addr1, someCoins, 2), NewTxInput(addr2, someCoins, 3)},
+				[]TxOutput{NewTxOutput(addr1, doubleCoins)}),
 			[]basecoin.Actor{addr1, addr2}},
 		// wrong permissions fail
 		{false,
-			SendTx{
-				Inputs:  []TxInput{NewTxInput(addr1, someCoins, 2)},
-				Outputs: []TxOutput{NewTxOutput(addr2, someCoins)}},
+			NewSendTx(
+				[]TxInput{NewTxInput(addr1, someCoins, 2)},
+				[]TxOutput{NewTxOutput(addr2, someCoins)}),
 			[]basecoin.Actor{}},
 		{false,
-			SendTx{
-				Inputs:  []TxInput{NewTxInput(addr1, someCoins, 2)},
-				Outputs: []TxOutput{NewTxOutput(addr2, someCoins)}},
+			NewSendTx(
+				[]TxInput{NewTxInput(addr1, someCoins, 2)},
+				[]TxOutput{NewTxOutput(addr2, someCoins)}),
 			[]basecoin.Actor{addr2}},
+		{false,
+			NewSendTx(
+				[]TxInput{NewTxInput(addr1, someCoins, 2), NewTxInput(addr2, someCoins, 3)},
+				[]TxOutput{NewTxOutput(addr1, doubleCoins)}),
+			[]basecoin.Actor{addr1}},
 		// invalid input fails
 		{false,
-			SendTx{
-				Inputs:  []TxInput{NewTxInput(addr1, minusCoins, 2)},
-				Outputs: []TxOutput{NewTxOutput(addr2, minusCoins)}},
+			NewSendTx(
+				[]TxInput{NewTxInput(addr1, minusCoins, 2)},
+				[]TxOutput{NewTxOutput(addr2, minusCoins)}),
 			[]basecoin.Actor{addr2}},
 	}
 
 	for i, tc := range cases {
 		ctx := stack.MockContext().WithPermissions(tc.perms...)
-		_, err := h.CheckTx(ctx, nil, tc.tx.Wrap())
+		_, err := checkTx(ctx, tc.tx)
 		if tc.valid {
 			assert.Nil(err, "%d: %+v", i, err)
 		} else {
 			assert.NotNil(err, "%d", i)
 		}
+	}
+}
 
-		_, err = h.DeliverTx(ctx, nil, tc.tx.Wrap())
-		if tc.valid {
+func TestDeliverTx(t *testing.T) {
+	assert := assert.New(t)
+	require := require.New(t)
+
+	// some sample settings
+	addr1 := basecoin.Actor{App: "coin", Address: []byte{1, 2}}
+	addr2 := basecoin.Actor{App: "role", Address: []byte{7, 8}}
+	addr3 := basecoin.Actor{App: "coin", Address: []byte{6, 5, 4, 3}}
+
+	someCoins := types.Coins{{"atom", 123}}
+	moreCoins := types.Coins{{"atom", 6487}}
+	diffCoins := moreCoins.Minus(someCoins)
+	otherCoins := types.Coins{{"eth", 11}}
+	mixedCoins := someCoins.Plus(otherCoins)
+
+	type money struct {
+		addr  basecoin.Actor
+		coins types.Coins
+	}
+
+	cases := []struct {
+		init  []money
+		tx    basecoin.Tx
+		perms []basecoin.Actor
+		final []money // nil for error
+	}{
+		{
+			[]money{{addr1, moreCoins}},
+			NewSendTx(
+				[]TxInput{NewTxInput(addr1, someCoins, 1)},
+				[]TxOutput{NewTxOutput(addr2, someCoins)}),
+			[]basecoin.Actor{addr1},
+			[]money{{addr1, diffCoins}, {addr2, someCoins}},
+		},
+		// simple multi-sig 2 accounts to 1
+		{
+			[]money{{addr1, mixedCoins}, {addr2, moreCoins}},
+			NewSendTx(
+				[]TxInput{NewTxInput(addr1, otherCoins, 1), NewTxInput(addr2, someCoins, 1)},
+				[]TxOutput{NewTxOutput(addr3, mixedCoins)}),
+			[]basecoin.Actor{addr1, addr2},
+			[]money{{addr1, someCoins}, {addr2, diffCoins}, {addr3, mixedCoins}},
+		},
+		// multi-sig with one account sending many times
+		{
+			[]money{{addr1, moreCoins.Plus(otherCoins)}},
+			NewSendTx(
+				[]TxInput{NewTxInput(addr1, otherCoins, 1), NewTxInput(addr1, someCoins, 2)},
+				[]TxOutput{NewTxOutput(addr2, mixedCoins)}),
+			[]basecoin.Actor{addr1},
+			[]money{{addr1, diffCoins}, {addr2, mixedCoins}},
+		},
+	}
+
+	h := NewHandler()
+	for i, tc := range cases {
+		// setup the cases....
+		store := types.NewMemKVStore()
+		for _, m := range tc.init {
+			acct := Account{Coins: m.coins}
+			err := storeAccount(store, h.makeKey(m.addr), acct)
+			require.Nil(err, "%d: %+v", i, err)
+		}
+
+		ctx := stack.MockContext().WithPermissions(tc.perms...)
+		_, err := h.DeliverTx(ctx, store, tc.tx)
+		if len(tc.final) > 0 { // valid
 			assert.Nil(err, "%d: %+v", i, err)
+			// make sure the final balances are correct
+			for _, f := range tc.final {
+				acct, err := loadAccount(store, h.makeKey(f.addr))
+				assert.Nil(err, "%d: %+v", i, err)
+				assert.Equal(f.coins, acct.Coins)
+			}
 		} else {
 			assert.NotNil(err, "%d", i)
+			// TODO: make sure balances unchanged!
 		}
 
 	}
+
 }

modules/coin/store.go

@@ -45,18 +45,24 @@ func (a Accountant) ChangeCoins(store types.KVStore, addr basecoin.Actor, coins
 // it doesn't save anything, that is up to you to decide (Check/Change Coins)
 func (a Accountant) updateCoins(store types.KVStore, addr basecoin.Actor, coins types.Coins, seq int) (acct Account, err error) {
 	acct, err = loadAccount(store, a.makeKey(addr))
+	// we can increase an empty account...
+	if IsNoAccountErr(err) && coins.IsPositive() {
+		err = nil
+	}
 	if err != nil {
 		return acct, err
 	}
 
-	// check sequence
-	if seq != acct.Sequence+1 {
-		return acct, ErrInvalidSequence()
+	// check sequence if we are deducting... ugh, need a cleaner replay protection
+	if !coins.IsPositive() {
+		if seq != acct.Sequence+1 {
+			return acct, ErrInvalidSequence()
+		}
+		acct.Sequence += 1
 	}
-	acct.Sequence += 1
 
 	// check amount
-	final := acct.Coins.Minus(coins)
+	final := acct.Coins.Plus(coins)
 	if !final.IsNonnegative() {
 		return acct, ErrInsufficientFunds()
 	}