Merge pull request #4907 from ethereum-optimism/jg/batcher_l2_reorg_tests

op-batcher: Unit test L2 Reorg Handling

op-batcher/batcher/channel_manager_test.go

+package batcher_test
+
+import (
+	"io"
+	"math/big"
+	"testing"
+
+	"github.com/ethereum-optimism/optimism/op-batcher/batcher"
+	"github.com/ethereum-optimism/optimism/op-node/eth"
+	"github.com/ethereum-optimism/optimism/op-node/rollup/derive"
+	"github.com/ethereum-optimism/optimism/op-node/testlog"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/trie"
+	"github.com/stretchr/testify/require"
+)
+
+// TestChannelManagerReturnsErrReorg ensures that the channel manager
+// detects a reorg when it has cached L1 blocks.
+func TestChannelManagerReturnsErrReorg(t *testing.T) {
+	log := testlog.Logger(t, log.LvlCrit)
+	m := batcher.NewChannelManager(log, batcher.ChannelConfig{})
+
+	a := types.NewBlock(&types.Header{
+		Number: big.NewInt(0),
+	}, nil, nil, nil, nil)
+	b := types.NewBlock(&types.Header{
+		Number:     big.NewInt(1),
+		ParentHash: a.Hash(),
+	}, nil, nil, nil, nil)
+	c := types.NewBlock(&types.Header{
+		Number:     big.NewInt(2),
+		ParentHash: b.Hash(),
+	}, nil, nil, nil, nil)
+	x := types.NewBlock(&types.Header{
+		Number:     big.NewInt(2),
+		ParentHash: common.Hash{0xff},
+	}, nil, nil, nil, nil)
+
+	err := m.AddL2Block(a)
+	require.NoError(t, err)
+	err = m.AddL2Block(b)
+	require.NoError(t, err)
+	err = m.AddL2Block(c)
+	require.NoError(t, err)
+	err = m.AddL2Block(x)
+	require.ErrorIs(t, err, batcher.ErrReorg)
+}
+
+// TestChannelManagerReturnsErrReorgWhenDrained ensures that the channel manager
+// detects a reorg even if it does not have any blocks inside it.
+func TestChannelManagerReturnsErrReorgWhenDrained(t *testing.T) {
+	log := testlog.Logger(t, log.LvlCrit)
+	m := batcher.NewChannelManager(log, batcher.ChannelConfig{
+		TargetFrameSize:  0,
+		MaxFrameSize:     100,
+		ApproxComprRatio: 1.0,
+	})
+	lBlock := types.NewBlock(&types.Header{
+		BaseFee:    big.NewInt(10),
+		Difficulty: common.Big0,
+		Number:     big.NewInt(100),
+	}, nil, nil, nil, trie.NewStackTrie(nil))
+	l1InfoTx, err := derive.L1InfoDeposit(0, lBlock, eth.SystemConfig{}, false)
+	require.NoError(t, err)
+	txs := []*types.Transaction{types.NewTx(l1InfoTx)}
+
+	a := types.NewBlock(&types.Header{
+		Number: big.NewInt(0),
+	}, txs, nil, nil, trie.NewStackTrie(nil))
+	x := types.NewBlock(&types.Header{
+		Number:     big.NewInt(1),
+		ParentHash: common.Hash{0xff},
+	}, txs, nil, nil, trie.NewStackTrie(nil))
+
+	err = m.AddL2Block(a)
+	require.NoError(t, err)
+
+	_, _, err = m.TxData(eth.BlockID{})
+	require.NoError(t, err)
+	_, _, err = m.TxData(eth.BlockID{})
+	require.ErrorIs(t, err, io.EOF)
+	err = m.AddL2Block(x)
+	require.ErrorIs(t, err, batcher.ErrReorg)
+}