chain+wallet: add TestMempoolAccept to chain interface

chain/bitcoind_client.go

@@ -217,6 +217,16 @@ func (c *BitcoindClient) SendRawTransaction(tx *wire.MsgTx,
 	return c.chainConn.client.SendRawTransaction(tx, allowHighFees)
 }
 
+// TestMempoolAcceptCmd returns result of mempool acceptance tests indicating
+// if raw transaction(s) would be accepted by mempool.
+//
+// NOTE: This is part of the chain.Interface interface.
+func (c *BitcoindClient) TestMempoolAccept(txns []*wire.MsgTx,
+	maxFeeRate float64) ([]*btcjson.TestMempoolAcceptResult, error) {
+
+	return c.chainConn.client.TestMempoolAccept(txns, maxFeeRate)
+}
+
 // Notifications returns a channel to retrieve notifications from.
 //
 // NOTE: This is part of the chain.Interface interface.

chain/btcd.go

@@ -39,6 +39,10 @@ type RPCClient struct {
 	quitMtx sync.Mutex
 }
 
+// A compile-time check to ensure that RPCClient satisfies the chain.Interface
+// interface.
+var _ Interface = (*RPCClient)(nil)
+
 // NewRPCClient creates a client connection to the server described by the
 // connect string.  If disableTLS is false, the remote RPC certificate must be
 // provided in the certs slice.  The connection is not established immediately,

chain/interface.go

@@ -3,6 +3,7 @@ package chain
 import (
 	"time"
 
+	"github.com/btcsuite/btcd/btcjson"
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/rpcclient"
@@ -47,6 +48,7 @@ type Interface interface {
 	NotifyBlocks() error
 	Notifications() <-chan interface{}
 	BackEnd() string
+	TestMempoolAccept([]*wire.MsgTx, float64) ([]*btcjson.TestMempoolAcceptResult, error)
 }
 
 // Notification types.  These are defined here and processed from from reading

chain/neutrino.go

@@ -6,6 +6,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/btcsuite/btcd/btcjson"
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/btcutil/gcs"
 	"github.com/btcsuite/btcd/btcutil/gcs/builder"
@@ -20,6 +21,10 @@ import (
 	"github.com/lightninglabs/neutrino/headerfs"
 )
 
+// ErrUnimplemented is returned when a certain method is not implemented for a
+// given interface.
+var ErrUnimplemented = errors.New("unimplemented")
+
 // NeutrinoClient is an implementation of the btcwallet chain.Interface interface.
 type NeutrinoClient struct {
 	CS NeutrinoChainService
@@ -63,6 +68,10 @@ type NeutrinoClient struct {
 	clientMtx sync.Mutex
 }
 
+// A compile-time check to ensure that RPCClient satisfies the chain.Interface
+// interface.
+var _ Interface = (*NeutrinoClient)(nil)
+
 // NewNeutrinoClient creates a new NeutrinoClient struct with a backing
 // ChainService.
 func NewNeutrinoClient(chainParams *chaincfg.Params,
@@ -217,6 +226,16 @@ func (s *NeutrinoClient) SendRawTransaction(tx *wire.MsgTx, allowHighFees bool)
 	return &hash, nil
 }
 
+// TestMempoolAcceptCmd returns result of mempool acceptance tests indicating
+// if raw transaction(s) would be accepted by mempool.
+//
+// NOTE: This is part of the chain.Interface interface.
+func (s *NeutrinoClient) TestMempoolAccept(txns []*wire.MsgTx,
+	maxFeeRate float64) ([]*btcjson.TestMempoolAcceptResult, error) {
+
+	return nil, ErrUnimplemented
+}
+
 // FilterBlocks scans the blocks contained in the FilterBlocksRequest for any
 // addresses of interest. For each requested block, the corresponding compact
 // filter will first be checked for matches, skipping those that do not report

wallet/mock.go

@@ -3,6 +3,7 @@ package wallet
 import (
 	"time"
 
+	"github.com/btcsuite/btcd/btcjson"
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
@@ -83,3 +84,13 @@ func (m *mockChainClient) Notifications() <-chan interface{} {
 func (m *mockChainClient) BackEnd() string {
 	return "mock"
 }
+
+// TestMempoolAcceptCmd returns result of mempool acceptance tests indicating
+// if raw transaction(s) would be accepted by mempool.
+//
+// NOTE: This is part of the chain.Interface interface.
+func (m *mockChainClient) TestMempoolAccept(txns []*wire.MsgTx,
+	maxFeeRate float64) ([]*btcjson.TestMempoolAcceptResult, error) {
+
+	return nil, nil
+}