rpc, ethclient, gethclient: make ethclient.Client take an RPCClient interface

ethclient/ethclient.go

@@ -32,9 +32,16 @@ import (
 	"github.com/ethereum/go-ethereum/rpc"
 )
 
+type RPCClient interface {
+	CallContext(ctx context.Context, result interface{}, method string, args ...interface{}) error
+	BatchCallContext(ctx context.Context, b []rpc.BatchElem) error
+	EthSubscribe(ctx context.Context, channel interface{}, args ...interface{}) (ethereum.Subscription, error)
+	Close()
+}
+
 // Client defines typed wrappers for the Ethereum RPC API.
 type Client struct {
-	c *rpc.Client
+	c RPCClient
 }
 
 // Dial connects a client to the given URL.
@@ -52,7 +59,7 @@ func DialContext(ctx context.Context, rawurl string) (*Client, error) {
 }
 
 // NewClient creates a client that uses the given RPC client.
-func NewClient(c *rpc.Client) *Client {
+func NewClient(c RPCClient) *Client {
 	return &Client{c}
 }
 
@@ -62,7 +69,7 @@ func (ec *Client) Close() {
 }
 
 // Client gets the underlying RPC client.
-func (ec *Client) Client() *rpc.Client {
+func (ec *Client) Client() RPCClient {
 	return ec.c
 }
 

ethclient/gethclient/gethclient.go

@@ -198,12 +198,12 @@ func (ec *Client) GetNodeInfo(ctx context.Context) (*p2p.NodeInfo, error) {
 }
 
 // SubscribeFullPendingTransactions subscribes to new pending transactions.
-func (ec *Client) SubscribeFullPendingTransactions(ctx context.Context, ch chan<- *types.Transaction) (*rpc.ClientSubscription, error) {
+func (ec *Client) SubscribeFullPendingTransactions(ctx context.Context, ch chan<- *types.Transaction) (ethereum.Subscription, error) {
 	return ec.c.EthSubscribe(ctx, ch, "newPendingTransactions", true)
 }
 
 // SubscribePendingTransactions subscribes to new pending transaction hashes.
-func (ec *Client) SubscribePendingTransactions(ctx context.Context, ch chan<- common.Hash) (*rpc.ClientSubscription, error) {
+func (ec *Client) SubscribePendingTransactions(ctx context.Context, ch chan<- common.Hash) (ethereum.Subscription, error) {
 	return ec.c.EthSubscribe(ctx, ch, "newPendingTransactions")
 }
 

rpc/client.go

@@ -28,6 +28,7 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/log"
 )
 
@@ -482,7 +483,7 @@ func (c *Client) Notify(ctx context.Context, method string, args ...interface{})
 }
 
 // EthSubscribe registers a subscription under the "eth" namespace.
-func (c *Client) EthSubscribe(ctx context.Context, channel interface{}, args ...interface{}) (*ClientSubscription, error) {
+func (c *Client) EthSubscribe(ctx context.Context, channel interface{}, args ...interface{}) (ethereum.Subscription, error) {
 	return c.Subscribe(ctx, "eth", channel, args...)
 }
 
@@ -498,7 +499,7 @@ func (c *Client) EthSubscribe(ctx context.Context, channel interface{}, args ...
 // before considering the subscriber dead. The subscription Err channel will receive
 // ErrSubscriptionQueueOverflow. Use a sufficiently large buffer on the channel or ensure
 // that the channel usually has at least one reader to prevent this issue.
-func (c *Client) Subscribe(ctx context.Context, namespace string, channel interface{}, args ...interface{}) (*ClientSubscription, error) {
+func (c *Client) Subscribe(ctx context.Context, namespace string, channel interface{}, args ...interface{}) (ethereum.Subscription, error) {
 	// Check type of channel first.
 	chanVal := reflect.ValueOf(channel)
 	if chanVal.Kind() != reflect.Chan || chanVal.Type().ChanDir()&reflect.SendDir == 0 {

rpc/client_test.go

@@ -34,6 +34,7 @@ import (
 	"time"
 
 	"github.com/davecgh/go-spew/spew"
+	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/log"
 )
 
@@ -496,7 +497,7 @@ func TestClientSubscribeClose(t *testing.T) {
 	var (
 		nc   = make(chan int)
 		errc = make(chan error, 1)
-		sub  *ClientSubscription
+		sub  ethereum.Subscription
 		err  error
 	)
 	go func() {
@@ -665,7 +666,12 @@ func TestClientSubscriptionUnsubscribeServer(t *testing.T) {
 
 	// Unsubscribe and check that unsubscribe was called.
 	sub.Unsubscribe()
-	if !recorder.unsubscribes[sub.subid] {
+
+	clientSub, ok := sub.(*ClientSubscription)
+	if !ok {
+		t.Fatal("subscription is not a ClientSubscription")
+	}
+	if !recorder.unsubscribes[clientSub.subid] {
 		t.Fatal("client did not call unsubscribe method")
 	}
 	if _, open := <-sub.Err(); open {