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fix(evmrpc): return empty array instead of null for eth_getFilterLogs and eth_getFilterChanges #3292

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Merged
amir-deris merged 2 commits into from
Apr 21, 2026
+85 −22
Merged

fix(evmrpc): return empty array instead of null for eth_getFilterLogs and eth_getFilterChanges #3292

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d34b9fc
getFilterLogs and getFilterChanges return empty array instead of nil,…
amir-deris Apr 21, 2026
393c2ff
Added constant for GetFilterChanges method
amir-deris Apr 21, 2026
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21 changes: 16 additions & 5 deletions evmrpc/filter.go
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Original file line number Diff line number Diff line change
Expand Up @@ -32,8 +32,6 @@ import (

var logger = seilog.NewLogger("evmrpc")

const TxSearchPerPage = 10

const (
// DB Concurrency Read Limit
MaxDBReadConcurrency = 16
Expand Down Expand Up @@ -388,6 +386,8 @@ func (a *FilterAPI) updateFilterAccess(filterID ethrpc.ID) {
}
}

const NewFilterMethod = "newFilter"

func (a *FilterAPI) NewFilter(
ctx context.Context,
crit filters.FilterCriteria,
Expand Down Expand Up @@ -437,6 +437,8 @@ func (a *FilterAPI) NewPendingTransactionFilter(
return "", &ErrEVMNotSupported{Msg: "eth_newPendingTransactionFilter is not supported on Sei EVM RPC"}
}

const GetFilterChangesMethod = "getFilterChanges"

func (a *FilterAPI) GetFilterChanges(
ctx context.Context,
filterID ethrpc.ID,
Expand All @@ -455,6 +457,7 @@ func (a *FilterAPI) GetFilterChanges(
// Update access time
a.updateFilterAccess(filterID)

result := []*ethtypes.Log{}
switch filter.typ {
case BlocksSubscription:
hashes, cursor, err := a.getBlockHeadersAfter(ctx, filter.blockCursor)
Expand All @@ -474,16 +477,19 @@ func (a *FilterAPI) GetFilterChanges(
case LogsSubscription:
// filter by hash would have no updates if it has previously queried for this crit
if filter.fc.BlockHash != nil && filter.lastToHeight > 0 {
return nil, nil
return result, nil
}
// filter with a ToBlock would have no updates if it has previously queried for this crit
if filter.fc.ToBlock != nil && filter.lastToHeight >= filter.fc.ToBlock.Int64() {
return nil, nil
return result, nil
}
logs, lastToHeight, err := a.logFetcher.GetLogsByFilters(ctx, filter.fc, filter.lastToHeight)
if err != nil {
return nil, err
}
if logs == nil {
logs = result
}

// Update filter with write lock
a.filtersMu.Lock()
Expand All @@ -499,6 +505,8 @@ func (a *FilterAPI) GetFilterChanges(
}
}

const GetFilterLogsMethod = "getFilterLogs"

func (a *FilterAPI) GetFilterLogs(
ctx context.Context,
filterID ethrpc.ID,
Expand All @@ -521,6 +529,9 @@ func (a *FilterAPI) GetFilterLogs(
if err != nil {
return nil, err
}
if logs == nil {
logs = []*ethtypes.Log{}
}

// Update filter with write lock
a.filtersMu.Lock()
Expand Down Expand Up @@ -942,7 +953,7 @@ func (f *LogFetcher) tryFilterLogsRange(ctx context.Context, fromBlock, toBlock
}

if len(logs) == 0 {
return logs, nil
return []*ethtypes.Log{}, nil
}

return f.normalizeRangeQueryLogs(ctx, logs, crit)
Expand Down
86 changes: 69 additions & 17 deletions evmrpc/filter_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -63,7 +63,7 @@ func TestFilterNew(t *testing.T) {
filterCriteria["fromBlock"] = tt.fromBlock
filterCriteria["toBlock"] = tt.toBlock
}
resObj := sendRequestGood(t, "newFilter", filterCriteria)
resObj := sendRequestGood(t, evmrpc.NewFilterMethod, filterCriteria)
_, errExists := resObj["error"]

if tt.wantErr {
Expand All @@ -72,7 +72,7 @@ func TestFilterNew(t *testing.T) {
require.False(t, errExists, "error should not exist")
got := resObj["result"].(string)
// make sure next filter id is not equal to this one
resObj := sendRequestGood(t, "newFilter", filterCriteria)
resObj := sendRequestGood(t, evmrpc.NewFilterMethod, filterCriteria)
got2 := resObj["result"].(string)
require.NotEqual(t, got, got2)
}
Expand All @@ -86,7 +86,7 @@ func TestFilterUninstall(t *testing.T) {
filterCriteria := map[string]interface{}{
"fromBlock": "0x1",
}
resObj := sendRequestGood(t, "newFilter", filterCriteria)
resObj := sendRequestGood(t, evmrpc.NewFilterMethod, filterCriteria)
filterId := resObj["result"].(string)
require.NotEmpty(t, filterId)

Expand Down Expand Up @@ -305,10 +305,10 @@ func TestFilterGetFilterLogs(t *testing.T) {
"fromBlock": "0x2",
"toBlock": "0x2",
}
resObj := sendRequestGood(t, "newFilter", filterCriteria)
resObj := sendRequestGood(t, evmrpc.NewFilterMethod, filterCriteria)
filterId := resObj["result"].(string)

resObj = sendRequest(t, TestPort, "getFilterLogs", filterId)
resObj = sendRequest(t, TestPort, evmrpc.GetFilterLogsMethod, filterId)
logs := resObj["result"].([]interface{})
require.Equal(t, 4, len(logs))
for _, log := range logs {
Expand All @@ -318,7 +318,7 @@ func TestFilterGetFilterLogs(t *testing.T) {

// error: filter id does not exist
nonexistentFilterId := 1000
resObj = sendRequest(t, TestPort, "getFilterLogs", nonexistentFilterId)
resObj = sendRequest(t, TestPort, evmrpc.GetFilterLogsMethod, nonexistentFilterId)
_, ok := resObj["error"]
require.True(t, ok)
}
Expand All @@ -328,10 +328,10 @@ func TestFilterGetFilterChanges(t *testing.T) {
filterCriteria := map[string]interface{}{
"fromBlock": "0x2",
}
resObj := sendRequest(t, TestPort, "newFilter", filterCriteria)
resObj := sendRequest(t, TestPort, evmrpc.NewFilterMethod, filterCriteria)
filterId := resObj["result"].(string)

resObj = sendRequest(t, TestPort, "getFilterChanges", filterId)
resObj = sendRequest(t, TestPort, evmrpc.GetFilterChangesMethod, filterId)
logs := resObj["result"].([]interface{})
// After tightening block/receipt matching, fromBlock=0x2 now yields 5 logs total
require.Equal(t, 5, len(logs))
Expand All @@ -340,7 +340,7 @@ func TestFilterGetFilterChanges(t *testing.T) {

// error: filter id does not exist
nonExistingFilterId := 1000
resObj = sendRequest(t, TestPort, "getFilterChanges", nonExistingFilterId)
resObj = sendRequest(t, TestPort, evmrpc.GetFilterChangesMethod, nonExistingFilterId)
_, ok := resObj["error"]
require.True(t, ok)
}
Expand All @@ -349,15 +349,15 @@ func TestFilterBlockFilter(t *testing.T) {
t.Parallel()
resObj := sendRequestGood(t, "newBlockFilter")
blockFilterId := resObj["result"].(string)
resObj = sendRequestGood(t, "getFilterChanges", blockFilterId)
resObj = sendRequestGood(t, evmrpc.GetFilterChangesMethod, blockFilterId)
hashesInterface := resObj["result"].([]interface{})
for _, hashInterface := range hashesInterface {
hash := hashInterface.(string)
require.Equal(t, 66, len(hash))
require.Equal(t, "0x", hash[:2])
}
// query again to make sure cursor is updated
resObj = sendRequestGood(t, "getFilterChanges", blockFilterId)
resObj = sendRequestGood(t, evmrpc.GetFilterChangesMethod, blockFilterId)
hashesInterface = resObj["result"].([]interface{})
for _, hashInterface := range hashesInterface {
hash := hashInterface.(string)
Expand All @@ -371,13 +371,13 @@ func TestFilterExpiration(t *testing.T) {
filterCriteria := map[string]interface{}{
"fromBlock": "0x1",
}
resObj := sendRequestGood(t, "newFilter", filterCriteria)
resObj := sendRequestGood(t, evmrpc.NewFilterMethod, filterCriteria)
filterId := resObj["result"].(string)

// wait for filter to expire
time.Sleep(2 * filterTimeoutDuration)

resObj = sendRequest(t, TestPort, "getFilterLogs", filterId)
resObj = sendRequest(t, TestPort, evmrpc.GetFilterLogsMethod, filterId)
_, ok := resObj["error"]
require.True(t, ok)
}
Expand All @@ -387,12 +387,12 @@ func TestFilterGetFilterLogsKeepsFilterAlive(t *testing.T) {
filterCriteria := map[string]interface{}{
"fromBlock": "0x1",
}
resObj := sendRequestGood(t, "newFilter", filterCriteria)
resObj := sendRequestGood(t, evmrpc.NewFilterMethod, filterCriteria)
filterId := resObj["result"].(string)

for i := 0; i < 5; i++ {
// should keep filter alive
resObj = sendRequestGood(t, "getFilterLogs", filterId)
resObj = sendRequestGood(t, evmrpc.GetFilterLogsMethod, filterId)
_, ok := resObj["error"]
require.False(t, ok)
time.Sleep(filterTimeoutDuration / 2)
Expand All @@ -404,12 +404,12 @@ func TestFilterGetFilterChangesKeepsFilterAlive(t *testing.T) {
filterCriteria := map[string]interface{}{
"fromBlock": "0x1",
}
resObj := sendRequestGood(t, "newFilter", filterCriteria)
resObj := sendRequestGood(t, evmrpc.NewFilterMethod, filterCriteria)
filterId := resObj["result"].(string)

for i := 0; i < 5; i++ {
// should keep filter alive
resObj = sendRequestGood(t, "getFilterChanges", filterId)
resObj = sendRequestGood(t, evmrpc.GetFilterChangesMethod, filterId)
_, ok := resObj["error"]
require.False(t, ok)
time.Sleep(filterTimeoutDuration / 2)
Expand Down Expand Up @@ -594,3 +594,55 @@ func TestCollectLogsEvmTransactionIndex(t *testing.T) {

require.Len(t, seen, len(expectedByHash), "should observe logs for all expected EVM txs in block 2")
}

// TestFilterGetFilterChangesEmptyOnExhaustedBoundedFilter asserts that
// eth_getFilterChanges returns [] (not null) once a bounded filter's range is
// fully consumed (Ethereum JSON-RPC spec requires an array, never null).
func TestFilterGetFilterChangesEmptyOnExhaustedBoundedFilter(t *testing.T) {
t.Parallel()
filterCriteria := map[string]interface{}{
"fromBlock": "0x2",
"toBlock": "0x2",
}
resObj := sendRequestGood(t, evmrpc.NewFilterMethod, filterCriteria)
filterId := resObj["result"].(string)

// First call: consumes the range; result may be non-empty, but must be an array.
resObj = sendRequest(t, TestPort, evmrpc.GetFilterChangesMethod, filterId)
_, hasErr := resObj["error"]
require.False(t, hasErr)
require.NotNil(t, resObj["result"], "first getFilterChanges should return [] not null")
_, ok := resObj["result"].([]interface{})
require.True(t, ok, "first getFilterChanges result should be an array")

// Second call: range is exhausted; must return [] not null.
resObj = sendRequest(t, TestPort, evmrpc.GetFilterChangesMethod, filterId)
_, hasErr = resObj["error"]
require.False(t, hasErr)
require.NotNil(t, resObj["result"], "exhausted getFilterChanges should return [] not null")
logs, ok := resObj["result"].([]interface{})
require.True(t, ok, "exhausted getFilterChanges result should be an array")
require.Empty(t, logs)
}

// TestFilterGetFilterLogsEmptyResultIsArray asserts that eth_getFilterLogs
// returns [] (not null) when no logs match the filter criteria.
func TestFilterGetFilterLogsEmptyResultIsArray(t *testing.T) {
t.Parallel()
// Use an address that is guaranteed to have no logs in the mock data.
filterCriteria := map[string]interface{}{
"fromBlock": "0x1",
"toBlock": "0x1",
"address": "0x0000000000000000000000000000000000000000",
}
resObj := sendRequestGood(t, evmrpc.NewFilterMethod, filterCriteria)
filterId := resObj["result"].(string)

resObj = sendRequest(t, TestPort, evmrpc.GetFilterLogsMethod, filterId)
_, hasErr := resObj["error"]
require.False(t, hasErr)
require.NotNil(t, resObj["result"], "getFilterLogs with no matching logs should return [] not null")
logs, ok := resObj["result"].([]interface{})
require.True(t, ok, "getFilterLogs result should be an array")
require.Empty(t, logs)
}
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