1 files changed, 149 insertions, 0 deletions
diff --git a/ledger/internal/cow_test.go b/ledger/internal/cow_test.go
new file mode 100644
index 000000000..968df87a0
--- /dev/null
+++ b/ledger/internal/cow_test.go
@@ -0,0 +1,149 @@
+// Copyright (C) 2019-2021 Algorand, Inc.
+// This file is part of go-algorand
+//
+// go-algorand is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// go-algorand is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with go-algorand.  If not, see <https://www.gnu.org/licenses/>.
+
+package internal
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/algorand/go-algorand/config"
+	"github.com/algorand/go-algorand/data/basics"
+	"github.com/algorand/go-algorand/data/bookkeeping"
+	"github.com/algorand/go-algorand/data/transactions"
+	"github.com/algorand/go-algorand/ledger/ledgercore"
+	ledgertesting "github.com/algorand/go-algorand/ledger/testing"
+	"github.com/algorand/go-algorand/protocol"
+	"github.com/algorand/go-algorand/test/partitiontest"
+)
+
+type mockLedger struct {
+	balanceMap map[basics.Address]basics.AccountData
+	blocks     map[basics.Round]bookkeeping.BlockHeader
+	blockErr   map[basics.Round]error
+}
+
+func (ml *mockLedger) lookup(addr basics.Address) (basics.AccountData, error) {
+	return ml.balanceMap[addr], nil
+}
+
+func (ml *mockLedger) checkDup(firstValid, lastValid basics.Round, txn transactions.Txid, txl ledgercore.Txlease) error {
+	return nil
+}
+
+func (ml *mockLedger) getAssetCreator(assetIdx basics.AssetIndex) (basics.Address, bool, error) {
+	return basics.Address{}, false, nil
+}
+
+func (ml *mockLedger) getAppCreator(appIdx basics.AppIndex) (basics.Address, bool, error) {
+	return basics.Address{}, false, nil
+}
+
+func (ml *mockLedger) getCreator(cidx basics.CreatableIndex, ctype basics.CreatableType) (basics.Address, bool, error) {
+	return basics.Address{}, false, nil
+}
+
+func (ml *mockLedger) getStorageCounts(addr basics.Address, aidx basics.AppIndex, global bool) (basics.StateSchema, error) {
+	return basics.StateSchema{}, nil
+}
+
+func (ml *mockLedger) getStorageLimits(addr basics.Address, aidx basics.AppIndex, global bool) (basics.StateSchema, error) {
+	return basics.StateSchema{}, nil
+}
+
+func (ml *mockLedger) allocated(addr basics.Address, aidx basics.AppIndex, global bool) (bool, error) {
+	return true, nil
+}
+
+func (ml *mockLedger) getKey(addr basics.Address, aidx basics.AppIndex, global bool, key string, accountIdx uint64) (basics.TealValue, bool, error) {
+	return basics.TealValue{}, false, nil
+}
+
+func (ml *mockLedger) txnCounter() uint64 {
+	return 0
+}
+
+func (ml *mockLedger) compactCertNext() basics.Round {
+	return 0
+}
+
+func (ml *mockLedger) blockHdr(rnd basics.Round) (bookkeeping.BlockHeader, error) {
+	err, hit := ml.blockErr[rnd]
+	if hit {
+		return bookkeeping.BlockHeader{}, err
+	}
+	hdr := ml.blocks[rnd] // default struct is fine if nothing found
+	return hdr, nil
+}
+
+func checkCow(t *testing.T, cow *roundCowState, accts map[basics.Address]basics.AccountData) {
+	for addr, data := range accts {
+		d, err := cow.lookup(addr)
+		require.NoError(t, err)
+		require.Equal(t, d, data)
+	}
+
+	d, err := cow.lookup(ledgertesting.RandomAddress())
+	require.NoError(t, err)
+	require.Equal(t, d, basics.AccountData{})
+}
+
+func applyUpdates(cow *roundCowState, updates ledgercore.AccountDeltas) {
+	for i := 0; i < updates.Len(); i++ {
+		addr, delta := updates.GetByIdx(i)
+		cow.Put(addr, delta)
+	}
+}
+
+func TestCowBalance(t *testing.T) {
+	partitiontest.PartitionTest(t)
+
+	accts0 := ledgertesting.RandomAccounts(20, true)
+	ml := mockLedger{balanceMap: accts0}
+
+	c0 := makeRoundCowState(
+		&ml, bookkeeping.BlockHeader{}, config.Consensus[protocol.ConsensusCurrentVersion],
+		0, ledgercore.AccountTotals{}, 0)
+	checkCow(t, c0, accts0)
+
+	c1 := c0.child(0)
+	checkCow(t, c0, accts0)
+	checkCow(t, c1, accts0)
+
+	updates1, accts1, _ := ledgertesting.RandomDeltas(10, accts0, 0)
+	applyUpdates(c1, updates1)
+	checkCow(t, c0, accts0)
+	checkCow(t, c1, accts1)
+
+	c2 := c1.child(0)
+	checkCow(t, c0, accts0)
+	checkCow(t, c1, accts1)
+	checkCow(t, c2, accts1)
+
+	updates2, accts2, _ := ledgertesting.RandomDeltas(10, accts1, 0)
+	applyUpdates(c2, updates2)
+	checkCow(t, c0, accts0)
+	checkCow(t, c1, accts1)
+	checkCow(t, c2, accts2)
+
+	c2.commitToParent()
+	checkCow(t, c0, accts0)
+	checkCow(t, c1, accts2)
+
+	c1.commitToParent()
+	checkCow(t, c0, accts2)
+}