add logs validation method in order to check if the log come from giv…

…en block (#122)

ethutil/validate_logs_with_block.go

@@ -0,0 +1,25 @@
+package ethutil
+
+import (
+	"bytes"
+
+	"github.com/0xsequence/ethkit/go-ethereum/core/types"
+)
+
+// ValidateLogsWithBlockHeader validates that the logs comes from given block.
+// If the list of logs is not complete or the logs are not from the block, it
+// will return false.
+func ValidateLogsWithBlockHeader(logs []types.Log, header *types.Header) bool {
+	return bytes.Compare(logsToBloom(logs).Bytes(), header.Bloom.Bytes()) == 0
+}
+
+func logsToBloom(logs []types.Log) types.Bloom {
+	var logBloom types.Bloom
+	for _, log := range logs {
+		logBloom.Add(log.Address.Bytes())
+		for _, b := range log.Topics {
+			logBloom.Add(b[:])
+		}
+	}
+	return logBloom
+}

ethutil/validate_logs_with_block_test.go

@@ -0,0 +1,28 @@
+package ethutil
+
+import (
+	"context"
+	"math/big"
+	"testing"
+
+	"github.com/0xsequence/ethkit/ethrpc"
+	"github.com/0xsequence/ethkit/go-ethereum"
+	"github.com/stretchr/testify/require"
+)
+
+func TestValidateLogsWithBlockHeader(t *testing.T) {
+	p, err := ethrpc.NewProvider("https://nodes.sequence.app/polygon")
+	require.NoError(t, err)
+
+	header, err := p.HeaderByNumber(context.Background(), big.NewInt(20_000_003))
+	require.NoError(t, err)
+	require.NotNil(t, header)
+
+	logs, err := p.FilterLogs(context.Background(), ethereum.FilterQuery{
+		FromBlock: big.NewInt(20_000_003),
+		ToBlock:   big.NewInt(20_000_003),
+	})
+	require.NoError(t, err)
+
+	require.True(t, ValidateLogsWithBlockHeader(logs, header))
+}