Add err match in the package chain

chain/bitcoind_client.go

@@ -214,7 +214,27 @@ func (c *BitcoindClient) GetTxOut(txHash *chainhash.Hash, index uint32,
 func (c *BitcoindClient) SendRawTransaction(tx *wire.MsgTx,
 	allowHighFees bool) (*chainhash.Hash, error) {
 
-	return c.chainConn.client.SendRawTransaction(tx, allowHighFees)
+	txid, err := c.chainConn.client.SendRawTransaction(tx, allowHighFees)
+	if err != nil {
+		return nil, c.MapRPCErr(err)
+	}
+
+	return txid, nil
+}
+
+// MapRPCErr takes an error returned from calling RPC methods from various
+// chain backends and maps it to an defined error here.
+func (c *BitcoindClient) MapRPCErr(rpcErr error) error {
+	// Try to match it against bitcoind's error.
+	for i := uint32(0); i < uint32(errSentinel); i++ {
+		err := RPCErr(i)
+		if matchErrStr(rpcErr, err.Error()) {
+			return err
+		}
+	}
+
+	// If not matched, return the original error wrapped.
+	return fmt.Errorf("%w: %v", ErrUndefined, rpcErr)
 }
 
 // TestMempoolAcceptCmd returns result of mempool acceptance tests indicating

chain/btcd.go

@@ -6,6 +6,7 @@ package chain
 
 import (
 	"errors"
+	"fmt"
 	"sync"
 	"time"
 
@@ -578,3 +579,62 @@ func (c *RPCClient) LookupInputMempoolSpend(op wire.OutPoint) (
 
 	return getTxSpendingPrevOut(op, c.Client)
 }
+
+// MapRPCErr takes an error returned from calling RPC methods from various
+// chain backends and maps it to an defined error here. It uses the
+// `BtcdErrMap`, whose keys are btcd error strings and values are errors made
+// from bitcoind error strings.
+func (c *RPCClient) MapRPCErr(rpcErr error) error {
+	// Iterate the map and find the matching error.
+	for btcdErr, matchedErr := range BtcdErrMap {
+		// Match it against btcd's error.
+		if matchErrStr(rpcErr, btcdErr) {
+			return matchedErr
+		}
+	}
+
+	// If no matching error is found, we try to match it to an older
+	// version of `btcd`.
+	//
+	// Get the backend's version.
+	backend, bErr := c.BackendVersion()
+	if bErr != nil {
+		// If there's an error getting the backend version, we return
+		// the original error and the backend error.
+		return fmt.Errorf("%w: %v, failed to get backend version %v",
+			ErrUndefined, rpcErr, bErr)
+	}
+
+	// If this version doesn't support `testmempoolaccept`, it must be
+	// below v0.24.2. In this case, we will match the errors defined in
+	// pre-v0.24.2.
+	//
+	// NOTE: `testmempoolaccept` is implemented in v0.24.1, but this
+	// version was never tagged, which means it must be v0.24.2 when it's
+	// supported.
+	if !backend.SupportTestMempoolAccept() {
+		// If the backend is older than v0.24.2, we will try to match
+		// the error to the older version of `btcd`.
+		for btcdErr, matchedErr := range BtcdErrMapPre2402 {
+			// Match it against btcd's error.
+			if matchErrStr(rpcErr, btcdErr) {
+				return matchedErr
+			}
+		}
+	}
+
+	// If not matched, return the original error wrapped.
+	return fmt.Errorf("%w: %v", ErrUndefined, rpcErr)
+}
+
+// SendRawTransaction sends a raw transaction via btcd.
+func (c *RPCClient) SendRawTransaction(tx *wire.MsgTx,
+	allowHighFees bool) (*chainhash.Hash, error) {
+
+	txid, err := c.Client.SendRawTransaction(tx, allowHighFees)
+	if err != nil {
+		return nil, c.MapRPCErr(err)
+	}
+
+	return txid, nil
+}