Create Signer interface and use it

types/ecpair.d.ts

@@ -5,15 +5,24 @@ interface ECPairOptions {
     network?: Network;
     rng?(arg0: number): Buffer;
 }
-export interface ECPairInterface {
+export interface Signer {
+    publicKey: Buffer;
+    network?: Network;
+    sign(hash: Buffer, lowR?: boolean): Buffer;
+    getPublicKey?(): Buffer;
+}
+export interface SignerAsync {
+    publicKey: Buffer;
+    network?: Network;
+    sign(hash: Buffer, lowR?: boolean): Promise<Buffer>;
+    getPublicKey?(): Buffer;
+}
+export interface ECPairInterface extends Signer {
     compressed: boolean;
     network: Network;
-    publicKey: Buffer;
     privateKey?: Buffer;
     toWIF(): string;
-    sign(hash: Buffer, lowR?: boolean): Buffer;
     verify(hash: Buffer, signature: Buffer): boolean;
-    getPublicKey?(): Buffer;
 }
 declare class ECPair implements ECPairInterface {
     private __D?;

types/index.d.ts

@@ -11,7 +11,7 @@ export { OPS as opcodes } from './script';
 export { Transaction } from './transaction';
 export { TransactionBuilder } from './transaction_builder';
 export { BIP32Interface } from 'bip32';
-export { ECPairInterface } from './ecpair';
+export { ECPairInterface, Signer, SignerAsync } from './ecpair';
 export { Network } from './networks';
 export { Payment, PaymentOpts, Stack, StackElement } from './payments';
 export { OpCode } from './script';

types/transaction_builder.d.ts

@@ -1,11 +1,11 @@
 /// <reference types="node" />
-import { ECPairInterface } from './ecpair';
+import { Signer } from './ecpair';
 import { Network } from './networks';
 import { Transaction } from './transaction';
 interface TxbSignArg {
     prevOutScriptType: string;
     vin: number;
-    keyPair: ECPairInterface;
+    keyPair: Signer;
     redeemScript?: Buffer;
     hashType?: number;
     witnessValue?: number;
@@ -27,7 +27,7 @@ export declare class TransactionBuilder {
     addOutput(scriptPubKey: string | Buffer, value: number): number;
     build(): Transaction;
     buildIncomplete(): Transaction;
-    sign(signParams: number | TxbSignArg, keyPair?: ECPairInterface, redeemScript?: Buffer, hashType?: number, witnessValue?: number, witnessScript?: Buffer): void;
+    sign(signParams: number | TxbSignArg, keyPair?: Signer, redeemScript?: Buffer, hashType?: number, witnessValue?: number, witnessScript?: Buffer): void;
     private __addInputUnsafe;
     private __build;
     private __canModifyInputs;