Merge pull request #54 from LedgerHQ/fixes/51

Better errors in libraries

.prettierignore

@@ -0,0 +1 @@
+package.json

packages/hw-transport-http/src/HttpTransport.js

@@ -1,5 +1,5 @@
 //@flow
-import Transport from "@ledgerhq/hw-transport";
+import Transport, { TransportError } from "@ledgerhq/hw-transport";
 import withStaticURL from "./withStaticURL";
 export { withStaticURL };
 
@@ -17,8 +17,12 @@ export default class HttpTransport extends Transport<string> {
   static async open(url: string, timeout?: number) {
     const response = await fetch(url, { timeout });
     if (response.status !== 200) {
-      throw new Error(
-        "failed to access HttpTransport(" + url + "): status " + response.status
+      throw new TransportError(
+        "failed to access HttpTransport(" +
+          url +
+          "): status " +
+          response.status,
+        "HttpTransportNotAccessible"
       );
     }
     return new HttpTransport(url);
@@ -50,7 +54,10 @@ export default class HttpTransport extends Transport<string> {
       body: JSON.stringify({ apduHex: apdu.toString("hex") })
     });
     if (response.status !== 200) {
-      throw "failed to communicate to server. code=" + response.status;
+      throw new TransportError(
+        "failed to communicate to server. code=" + response.status,
+        "HttpTransportStatus" + response.status
+      );
     }
     const body = await response.json();
     if (body.error) throw body.error;

packages/hw-transport-http/src/withStaticURL.js

@@ -1,18 +1,27 @@
 // @flow
 import HttpTransport from "./HttpTransport";
+import type {
+  Observer,
+  DescriptorEvent,
+  Subscription
+} from "@ledgerhq/hw-transport";
+
 export default (urlArg: ?string): Class<HttpTransport> => {
   const url = urlArg;
   if (!url) return HttpTransport; // by default, HttpTransport don't yield anything in list/listen
   class StaticHttpTransport extends HttpTransport {
-    static list = (): * => HttpTransport.open(url).then(() => [url], () => []);
-    static listen = (observer: *) => {
+    static list = (): Promise<string[]> =>
+      HttpTransport.open(url).then(() => [url], () => []);
+
+    static listen = (
+      observer: Observer<DescriptorEvent<string>>
+    ): Subscription => {
       let unsubscribed = false;
       function attemptToConnect() {
         if (unsubscribed) return;
         HttpTransport.open(url, 5000).then(
           () => {
             if (unsubscribed) return;
-            // $FlowFixMe wtf flow
             observer.next({ type: "add", descriptor: url });
             observer.complete();
           },

packages/hw-transport-node-hid/src/TransportNodeHid.js

@@ -1,7 +1,12 @@
 //@flow
 
 import HID from "node-hid";
-import Transport from "@ledgerhq/hw-transport";
+import Transport, { TransportError } from "@ledgerhq/hw-transport";
+import type {
+  Observer,
+  DescriptorEvent,
+  Subscription
+} from "@ledgerhq/hw-transport";
 import getDevices from "./getDevices";
 import listenDevices from "./listenDevices";
 
@@ -17,7 +22,7 @@ function defer<T>(): Defer<T> {
     resolve = success;
     reject = failure;
   });
-  if (!resolve || !reject) throw "defer() error"; // this never happens and is just to make flow happy
+  if (!resolve || !reject) throw new Error("defer() error"); // this never happens and is just to make flow happy
   return { promise, resolve, reject };
 }
 
@@ -49,14 +54,20 @@ export default class TransportNodeHid extends Transport<string> {
     this.debug = debug;
   }
 
-  static list = () => Promise.resolve(getDevices().map(d => d.path));
+  static list = (): Promise<string[]> =>
+    Promise.resolve(getDevices().map(d => d.path));
 
-  static listen = (observer: *) => {
+  /**
+   */
+  static listen = (
+    observer: Observer<DescriptorEvent<string>>
+  ): Subscription => {
     let unsubscribed = false;
     const devices = getDevices();
     for (const device of devices) {
       if (!unsubscribed) {
-        observer.next({ type: "add", descriptor: device.path, device });
+        const descriptor: string = device.path;
+        observer.next({ type: "add", descriptor, device });
       }
     }
 
@@ -79,21 +90,10 @@ export default class TransportNodeHid extends Transport<string> {
     return { unsubscribe };
   };
 
-  static async open(path: string) {
-    return Promise.resolve(new TransportNodeHid(new HID.HID(path)));
-  }
-
   /**
-   * static function to create a new Transport from the first connected Ledger device found in USB
-
    */
-  static create(timeout?: number, debug?: boolean): Promise<TransportNodeHid> {
-    return TransportNodeHid.list().then(result => {
-      if (result.length === 0) {
-        throw "No device found";
-      }
-      return new TransportNodeHid(new HID.HID(result[0]), true, timeout, debug);
-    });
+  static async open(path: string) {
+    return Promise.resolve(new TransportNodeHid(new HID.HID(path)));
   }
 
   exchange(apdu: Buffer): Promise<Buffer> {
@@ -142,19 +142,19 @@ export default class TransportNodeHid extends Transport<string> {
         return;
       }
       if (data[offset++] !== channel >> 8) {
-        throw "Invalid channel;";
+        throw new TransportError("Invalid channel", "InvalidChannel");
       }
       if (data[offset++] !== (channel & 0xff)) {
-        throw "Invalid channel";
+        throw new TransportError("Invalid channel", "InvalidChannel");
       }
       if (data[offset++] !== 0x05) {
-        throw "Invalid tag";
+        throw new TransportError("Invalid tag", "InvalidTag");
       }
       if (data[offset++] !== 0x00) {
-        throw "Invalid sequence";
+        throw new TransportError("Invalid sequence", "InvalidSequence");
       }
       if (data[offset++] !== 0x00) {
-        throw "Invalid sequence";
+        throw new TransportError("Invalid sequence", "InvalidSequence");
       }
       responseLength = (data[offset++] & 0xff) << 8;
       responseLength |= data[offset++] & 0xff;
@@ -171,19 +171,19 @@ export default class TransportNodeHid extends Transport<string> {
           return;
         }
         if (data[offset++] !== channel >> 8) {
-          throw "Invalid channel;";
+          throw new TransportError("Invalid channel", "InvalidChannel");
         }
         if (data[offset++] !== (channel & 0xff)) {
-          throw "Invalid channel";
+          throw new TransportError("Invalid channel", "InvalidChannel");
         }
         if (data[offset++] !== 0x05) {
-          throw "Invalid tag";
+          throw new TransportError("Invalid tag", "InvalidTag");
         }
         if (data[offset++] !== sequenceIdx >> 8) {
-          throw "Invalid sequence";
+          throw new TransportError("Invalid sequence", "InvalidSequence");
         }
         if (data[offset++] !== (sequenceIdx & 0xff)) {
-          throw "Invalid sequence";
+          throw new TransportError("Invalid sequence", "InvalidSequence");
         }
         blockSize =
           responseLength - response.length > packetSize - 5
@@ -213,7 +213,7 @@ export default class TransportNodeHid extends Transport<string> {
     if (this.timeout !== 0) {
       exchangeTimeout = setTimeout(() => {
         // Node.js supports timeouts
-        deferred.reject("timeout");
+        deferred.reject(new TransportError("timeout", "timeout"));
       }, this.timeout);
     }
 

packages/hw-transport/package.json

@@ -23,8 +23,7 @@
   "main": "lib/Transport.js",
   "license": "Apache-2.0",
   "dependencies": {
-    "events": "^1.1.1",
-    "invariant": "^2.2.0"
+    "events": "^1.1.1"
   },
   "devDependencies": {
     "flow-bin": "^0.63.1",

packages/hw-transport/src/Transport.js

@@ -1,19 +1,83 @@
 //@flow
 
-import invariant from "invariant";
 import EventEmitter from "events";
 
+/**
+ */
 export type Subscription = { unsubscribe: () => void };
+/**
+ */
 export type DescriptorEvent<Descriptor> = {
   type: "add" | "remove",
   descriptor: Descriptor
 };
-export type Observer<Descriptor> = {
-  next: (event: DescriptorEvent<Descriptor>) => void,
+/**
+ */
+export type Observer<Ev> = {
+  next: (event: Ev) => void,
   error: (e: ?Error) => void,
   complete: () => void
 };
 
+/**
+ * all possible status codes.
+ * @see https://ledgerhq.github.io/btchip-doc/bitcoin-technical.html#_status_words
+ * @example
+ * import { StatusCodes } from "@ledgerhq/hw-transport";
+ */
+export const StatusCodes = {
+  /**
+   * Incorrect length
+   */
+  IncorrectLength: 0x6700,
+  /**
+   * Security status not satisfied (Bitcoin dongle is locked or invalid access rights)
+   */
+  SecurityNotSatisfied: 0x6982,
+  /**
+   * Invalid data
+   */
+  InvalidData: 0x6a80,
+  /**
+   * File not found
+   */
+  FileNotFound: 0x6a82,
+  /**
+   * Incorrect parameter P1 or P2
+   */
+  IncorrectParameter: 0x6b00,
+  /**
+   * Success
+   */
+  Success: 0x9000
+};
+
+/**
+ * TransportError is used for any generic transport errors.
+ * e.g. Error thrown when data received by exchanges are incorrect or if exchanged failed to communicate with the device for various reason.
+ */
+export function TransportError(message: string, id: string) {
+  this.name = "TransportError";
+  this.message = message;
+  this.stack = new Error().stack;
+  this.id = id;
+}
+//$FlowFixMe
+TransportError.prototype = new Error();
+
+/**
+ * Error thrown when a device returned a non success status.
+ * the error.statusCode is one of the `StatusCodes` exported by this library.
+ */
+export function TransportStatusError(statusCode: number) {
+  this.name = "TransportStatusError";
+  this.message = "Invalid status " + statusCode.toString(16);
+  this.stack = new Error().stack;
+  this.statusCode = statusCode;
+}
+//$FlowFixMe
+TransportStatusError.prototype = new Error();
+
 /**
  * Transport defines the generic interface to share between node/u2f impl
  * A **Descriptor** is a parametric type that is up to be determined for the implementation.
@@ -134,13 +198,14 @@ TransportFoo.open(descriptor).then(transport => ...)
     p1: number,
     p2: number,
     data: Buffer = Buffer.alloc(0),
-    statusList: Array<number> = [0x9000]
+    statusList: Array<number> = [StatusCodes.Success]
   ): Promise<Buffer> => {
-    invariant(
-      data.length < 256,
-      "data.length exceed 256 bytes limit. Got: %s",
-      data.length
-    );
+    if (data.length >= 256) {
+      throw new TransportError(
+        "data.length exceed 256 bytes limit. Got: " + data.length,
+        "DataLengthTooBig"
+      );
+    }
     const response = await this.exchange(
       Buffer.concat([
         Buffer.from([cla, ins, p1, p2]),
@@ -149,11 +214,9 @@ TransportFoo.open(descriptor).then(transport => ...)
       ])
     );
     const sw = response.readUInt16BE(response.length - 2);
-    invariant(
-      statusList.some(s => s === sw),
-      "Invalid status %s",
-      sw.toString(16)
-    );
+    if (!statusList.some(s => s === sw)) {
+      throw new TransportStatusError(sw);
+    }
     return response;
   };
 
@@ -170,7 +233,9 @@ TransportFoo.open(descriptor).then(transport => ...)
         ".create is deprecated. Please use .list()/.listen() and .open() instead"
     );
     const descriptors = await this.list();
-    invariant(descriptors.length !== 0, "No device found");
+    if (descriptors.length === 0) {
+      throw new TransportError("No device found", "NoDeviceFound");
+    }
     const transport = await this.open(descriptors[0], timeout);
     transport.setDebugMode(debug);
     return transport;