improved error management (#24)

Author: jleni

src/app.test.ts

@@ -30,8 +30,15 @@ describe('BaseApp', () => {
 
   describe('prepareChunks', () => {
     it('should prepare chunks correctly', () => {
+      // subclassing to expose protected method
+      class TestBaseApp extends BaseApp {
+        public prepareChunks(path: string, message: Buffer) {
+          return super.prepareChunks(path, message)
+        }
+      }
+
       const transport = new MockTransport(Buffer.alloc(0))
-      const app = new BaseApp(transport, params)
+      const app = new TestBaseApp(transport, params)
       const path = "m/44'/0'/0'"
       const message = Buffer.from('test message')
       const chunks = app.prepareChunks(path, message)

src/app.ts

@@ -46,6 +46,10 @@ export default class BaseApp {
    * @param params - The constructor parameters.
    */
   constructor(transport: Transport, params: ConstructorParams) {
+    if (transport == null) {
+      throw new Error('Transport has not been defined')
+    }
+
     this.transport = transport
     this.CLA = params.cla
     this.INS = params.ins
@@ -69,7 +73,7 @@ export default class BaseApp {
    * @param message - The message to be sent.
    * @returns An array of buffers that are ready to be sent.
    */
-  prepareChunks(path: string, message: Buffer): Buffer[] {
+  protected prepareChunks(path: string, message: Buffer): Buffer[] {
     const chunks = []
     const serializedPathBuffer = this.serializePath(path)
 
@@ -98,7 +102,7 @@ export default class BaseApp {
    * @returns A promise that resolves to the processed response from the device.
    * @throws {ResponseError} If the response from the device indicates an error.
    */
-  async signSendChunk(ins: number, chunkIdx: number, chunkNum: number, chunk: Buffer): Promise<ResponsePayload> {
+  protected async signSendChunk(ins: number, chunkIdx: number, chunkNum: number, chunk: Buffer): Promise<ResponsePayload> {
     let payloadType = PAYLOAD_TYPE.ADD
 
     if (chunkIdx === 1) {

src/bip32.ts

@@ -20,7 +20,7 @@ import { ResponseError } from './responseError'
  * Serializes a derivation path into a buffer.
  * @param path - The derivation path in string format.
  * @returns A buffer representing the serialized path.
- * @throws {Error} If the path format is incorrect or invalid.
+ * @throws {ResponseError} If the path format is incorrect or invalid.
  */
 export function serializePath(path: string, requiredPathLengths?: number[]): Buffer {
   if (typeof path !== 'string') {
@@ -73,12 +73,15 @@ export function serializePath(path: string, requiredPathLengths?: number[]): Buf
  */
 export function numbersToBip32Path(items: number[]): string {
   if (items.length === 0) {
-    throw new Error('The items array cannot be empty.')
+    throw new ResponseError(LedgerError.GenericError, 'The items array cannot be empty.')
   }
 
   const pathArray = []
   for (let i = 0; i < items.length; i++) {
     let value = items[i]
+    if (!Number.isInteger(value) || value < 0) {
+      throw new ResponseError(LedgerError.GenericError, 'Each item must be a positive integer.')
+    }
     let child = value & ~HARDENED
 
     if (value >= HARDENED) {
@@ -90,7 +93,6 @@ export function numbersToBip32Path(items: number[]): string {
 
   return 'm/' + pathArray.join('/')
 }
-
 /**
  * Converts a buffer representing a serialized path back into a derivation path string.
  * @param buffer - The buffer representing the serialized path.
@@ -99,7 +101,7 @@ export function numbersToBip32Path(items: number[]): string {
  */
 export function bufferToBip32Path(buffer: Buffer): string {
   if (buffer.length % 4 !== 0) {
-    throw new Error('The buffer length must be a multiple of 4.')
+    throw new ResponseError(LedgerError.GenericError, 'The buffer length must be a multiple of 4.')
   }
 
   const items = []

src/index.ts

@@ -22,3 +22,6 @@ export type { default as Transport } from '@ledgerhq/hw-transport'
 export * from './common'
 export * from './consts'
 export * from './types'
+export * from './bip32'
+export * from './responseError'
+export * from './payload'