fix type errors

src/@types/it-length-prefixed/index.d.ts

@@ -1,7 +1,6 @@
-declare module "it-length-prefixed" {
-  /* eslint-disable @typescript-eslint/interface-name-prefix */
-  import BufferList from "bl";
-  import {Buffer} from "buffer"
+declare module 'it-length-prefixed' {
+  import BufferList from 'bl'
+  import { Buffer } from 'buffer'
 
   interface LengthDecoderFunction {
     (data: Buffer | BufferList): number;
@@ -9,7 +8,7 @@ declare module "it-length-prefixed" {
   }
 
   interface LengthEncoderFunction {
-    (value: Buffer, target: number, offset: number): number|Buffer;
+    (value: number, target: Buffer, offset: number): number|Buffer;
     bytes: number;
   }
 
@@ -33,7 +32,7 @@ declare module "it-length-prefixed" {
     MAX_DATA_LENGTH: number;
   }
 
-  export const encode: Encoder;
-  export const decode: Decoder;
+  export const encode: Encoder
+  export const decode: Decoder
 
 }

src/encoder.ts

@@ -1,15 +1,16 @@
 import { Buffer } from 'buffer'
 import { bytes } from './@types/basic'
 import { MessageBuffer } from './@types/handshake'
+import BufferList from 'bl'
 
-export const uint16BEEncode = (value: number, target: bytes, offset: number): bytes => {
+export const uint16BEEncode = (value: number, target: Buffer, offset: number): Buffer => {
   target = target || Buffer.allocUnsafe(2)
   target.writeUInt16BE(value, offset)
   return target
 }
 uint16BEEncode.bytes = 2
 
-export const uint16BEDecode = (data: bytes): number => {
+export const uint16BEDecode = (data: Buffer | BufferList): number => {
   if (data.length < 2) throw RangeError('Could not decode int16BE')
   return data.readUInt16BE(0)
 }

src/errors.ts

@@ -1,7 +1,9 @@
-export class FailedIKError extends Error {
-  public initialMsg: string;
+import BufferList from 'bl'
 
-  constructor (initialMsg: string, message?: string) {
+export class FailedIKError extends Error {
+  public initialMsg: string|BufferList|Buffer;
+
+  constructor (initialMsg: string|BufferList|Buffer, message?: string) {
     super(message)
 
     this.initialMsg = initialMsg