// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package state

import (
	"math/big"
	"testing"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/ethdb"
)

// Tests that updating a state trie does not leak any database writes prior to
// actually committing the state.
func TestUpdateLeaks(t *testing.T) {
	// Create an empty state database
	db, _ := ethdb.NewMemDatabase()
	state, _ := New(common.Hash{}, db)

	// Update it with some accounts
	for i := byte(0); i < 255; i++ {
		obj := state.GetOrNewStateObject(common.BytesToAddress([]byte{i}))
		obj.AddBalance(big.NewInt(int64(11 * i)))
		obj.SetNonce(uint64(42 * i))
		if i%2 == 0 {
			obj.SetState(common.BytesToHash([]byte{i, i, i}), common.BytesToHash([]byte{i, i, i, i}))
		}
		if i%3 == 0 {
			obj.SetCode([]byte{i, i, i, i, i})
		}
		state.UpdateStateObject(obj)
	}
	// Ensure that no data was leaked into the database
	for _, key := range db.Keys() {
		value, _ := db.Get(key)
		t.Errorf("State leaked into database: %x -> %x", key, value)
	}
}