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package client
import (
"context"
"errors"
"sync"
"testing"
"time"
"github.com/ethereum/go-ethereum"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/rpc"
"github.com/stretchr/testify/require"
)
type MockRPC struct {
t *testing.T
callResults []*callResult
mtx sync.RWMutex
callCount int
autopop bool
closed bool
}
type callResult struct {
root common.Hash
error error
}
func (m *MockRPC) Close() {
m.closed = true
}
func (m *MockRPC) CallContext(ctx context.Context, result any, method string, args ...any) error {
m.mtx.Lock()
defer m.mtx.Unlock()
if method != "eth_getBlockByNumber" {
m.t.Fatalf("invalid method %s", method)
}
if args[0] != "latest" {
m.t.Fatalf("invalid arg %v", args[0])
}
m.callCount++
res := m.callResults[0]
headerP := result.(**types.Header)
*headerP = &types.Header{
Root: res.root,
}
if m.autopop {
m.callResults = m.callResults[1:]
}
return res.error
}
func (m *MockRPC) BatchCallContext(ctx context.Context, b []rpc.BatchElem) error {
m.t.Fatal("BatchCallContext should not be called")
return nil
}
func (m *MockRPC) EthSubscribe(ctx context.Context, channel any, args ...any) (ethereum.Subscription, error) {
m.t.Fatal("EthSubscribe should not be called")
return nil, nil
}
func (m *MockRPC) popResult() {
m.mtx.Lock()
defer m.mtx.Unlock()
m.callResults = m.callResults[1:]
}
func TestPollingClientSubscribeUnsubscribe(t *testing.T) {
lgr := log.New()
lgr.SetHandler(log.DiscardHandler())
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
root1 := common.Hash{0x01}
root2 := common.Hash{0x02}
root3 := common.Hash{0x03}
mockRPC := &MockRPC{
t: t,
callResults: []*callResult{
{root1, nil},
{root2, nil},
{root3, nil},
},
}
client := NewPollingClient(ctx, lgr, mockRPC, WithPollRate(0))
subs := make([]ethereum.Subscription, 0)
chans := make([]chan *types.Header, 0)
for i := 0; i < 2; i++ {
ch := make(chan *types.Header, 2)
sub, err := doSubscribe(client, ch)
require.NoError(t, err)
subs = append(subs, sub)
chans = append(chans, ch)
}
client.reqPoll()
requireChansEqual(t, chans, root1)
mockRPC.popResult()
client.reqPoll()
requireChansEqual(t, chans, root2)
// Poll an additional time to show that responses with the same
// data don't notify again.
client.reqPoll()
// Verify that no further notifications have been sent.
for _, ch := range chans {
select {
case <-ch:
t.Fatal("unexpected notification")
case <-time.NewTimer(10 * time.Millisecond).C:
continue
}
}
mockRPC.popResult()
subs[0].Unsubscribe()
client.reqPoll()
select {
case <-chans[0]:
t.Fatal("unexpected notification")
case <-time.NewTimer(10 * time.Millisecond).C:
}
header := <-chans[1]
require.Equal(t, root3, header.Root)
}
func TestPollingClientErrorRecovery(t *testing.T) {
lgr := log.New()
lgr.SetHandler(log.DiscardHandler())
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
root := common.Hash{0x01}
mockRPC := &MockRPC{
t: t,
callResults: []*callResult{
{common.Hash{}, errors.New("foobar")},
{common.Hash{}, errors.New("foobar")},
{root, nil},
},
autopop: true,
}
client := NewPollingClient(ctx, lgr, mockRPC, WithPollRate(0))
ch := make(chan *types.Header, 1)
sub, err := doSubscribe(client, ch)
require.NoError(t, err)
defer sub.Unsubscribe()
for i := 0; i < 3; i++ {
client.reqPoll()
}
header := <-ch
require.Equal(t, root, header.Root)
require.Equal(t, 3, mockRPC.callCount)
}
func TestPollingClientClose(t *testing.T) {
lgr := log.New()
lgr.SetHandler(log.DiscardHandler())
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
root := common.Hash{0x01}
mockRPC := &MockRPC{
t: t,
callResults: []*callResult{
{root, nil},
},
autopop: true,
}
client := NewPollingClient(ctx, lgr, mockRPC, WithPollRate(0))
ch := make(chan *types.Header, 1)
sub, err := doSubscribe(client, ch)
require.NoError(t, err)
client.reqPoll()
header := <-ch
cancel()
require.Nil(t, <-sub.Err())
require.Equal(t, root, header.Root)
require.Equal(t, 1, mockRPC.callCount)
// unsubscribe should be safe
sub.Unsubscribe()
_, err = doSubscribe(client, ch)
require.Equal(t, ErrSubscriberClosed, err)
}
func requireChansEqual(t *testing.T, chans []chan *types.Header, root common.Hash) {
t.Helper()
for _, ch := range chans {
header := <-ch
require.Equal(t, root, header.Root)
}
}
func doSubscribe(client RPC, ch chan<- *types.Header) (ethereum.Subscription, error) {
return client.EthSubscribe(context.Background(), ch, "newHeads")
}