bluetooth: show better error messages for services, characteristics and descriptors

third_party/WebKit/Source/modules/bluetooth/BluetoothError.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/bluetooth/BluetoothError.h"
 
 #include "core/dom/DOMException.h"
 #include "core/dom/ExceptionCode.h"
 
 namespace blink {
 
-DOMException* BluetoothError::take(ScriptPromiseResolver*,
-                                   mojom::blink::WebBluetoothResult error) {
+// static
+DOMException* BluetoothError::createDOMException(
+    mojom::blink::WebBluetoothResult error,
+    const String& detailedMessage) {
   switch (error) {
     case mojom::blink::WebBluetoothResult::SUCCESS:
-      ASSERT_NOT_REACHED();
+      NOTREACHED();
+      return DOMException::create(UnknownError);
+    case mojom::blink::WebBluetoothResult::SERVICE_NOT_FOUND:
+      return DOMException::create(NotFoundError, detailedMessage);
+    case mojom::blink::WebBluetoothResult::CHARACTERISTIC_NOT_FOUND:
+      return DOMException::create(NotFoundError, detailedMessage);
+    case mojom::blink::WebBluetoothResult::DESCRIPTOR_NOT_FOUND:
+      return DOMException::create(NotFoundError, detailedMessage);
+    case mojom::blink::WebBluetoothResult::INVALID_SERVICE:
+      return DOMException::create(InvalidStateError, detailedMessage);
+    case mojom::blink::WebBluetoothResult::INVALID_CHARACTERISTIC:
+      return DOMException::create(InvalidStateError, detailedMessage);
+    case mojom::blink::WebBluetoothResult::INVALID_DESCRIPTOR:
+      return DOMException::create(InvalidStateError, detailedMessage);
+    default:
+      NOTREACHED();
+      return DOMException::create(UnknownError);
+  }
+}
+
+// static
+DOMException* BluetoothError::createDOMException(
+    mojom::blink::WebBluetoothResult error) {
+  switch (error) {
+    case mojom::blink::WebBluetoothResult::SUCCESS:
+      NOTREACHED();
       return DOMException::create(UnknownError);
 #define MAP_ERROR(enumeration, name, message)         \
   case mojom::blink::WebBluetoothResult::enumeration: \
-    return DOMException::create(name, message)
+    return DOMException::create(name, message);
 
       // InvalidModificationErrors:
       MAP_ERROR(GATT_INVALID_ATTRIBUTE_LENGTH, InvalidModificationError,
                 "GATT Error: invalid attribute length.");
 
       // InvalidStateErrors:
       MAP_ERROR(SERVICE_NO_LONGER_EXISTS, InvalidStateError,
                 "GATT Service no longer exists.");
       MAP_ERROR(CHARACTERISTIC_NO_LONGER_EXISTS, InvalidStateError,
                 "GATT Characteristic no longer exists.");
       MAP_ERROR(DESCRIPTOR_NO_LONGER_EXISTS, InvalidStateError,
                 "GATT Descriptor no longer exists.");
+      MAP_ERROR(INVALID_CHARACTERISTIC, InvalidStateError,
+                "Characteristic is no longer valid. Remember to retrieve the "
+                "characteristic again after reconnecting.");
+      MAP_ERROR(INVALID_DESCRIPTOR, InvalidStateError,
+                "Descriptor is no longer valid. Remember to retrieve the "
+                "Descriptor again after reconnecting.");
+      MAP_ERROR(INVALID_SERVICE, InvalidStateError,

[scheib, 2017/02/10 18:25:34]

This new pattern does not LGTM. (Sorry for noticing this late.) It creates case
handlers that won't be executed, and in this file need to either be
speculatively filled in or runtime checked with NOTREACHED(). We end up
duplicating handlers e.g. for INVALID_SERVICE.

I suggest we split the mojom enum WebBluetoothResult into two:
enum WebBluetoothResult
enum WebBluetoothResultWithMessage
and each handler will know precisely how to handle that enum. I think all enums
will fall into only one or the other.

We should avoid switch statements having a "default:" handler, so that the
compiler can help us verify that all cases are handled.

+                "Service is no longer valid. Remember to retrieve the service "
+                "again after reconnecting.");
 
       // NetworkErrors:
       MAP_ERROR(CONNECT_ALREADY_IN_PROGRESS, NetworkError,
                 "Connection already in progress.");
       MAP_ERROR(CONNECT_ATTRIBUTE_LENGTH_INVALID, NetworkError,
                 "Write operation exceeds the maximum length of the attribute.");
       MAP_ERROR(CONNECT_AUTH_CANCELED, NetworkError,
                 "Authentication canceled.");
       MAP_ERROR(CONNECT_AUTH_FAILED, NetworkError, "Authentication failed.");
       MAP_ERROR(CONNECT_AUTH_REJECTED, NetworkError,
@@ skipping 18 matching lines @@
                 "Unsupported device.");
       MAP_ERROR(CONNECT_WRITE_NOT_PERMITTED, NetworkError,
                 "GATT write operation is not permitted.");
       MAP_ERROR(DEVICE_NO_LONGER_IN_RANGE, NetworkError,
                 "Bluetooth Device is no longer in range.");
       MAP_ERROR(GATT_NOT_PAIRED, NetworkError, "GATT Error: Not paired.");
       MAP_ERROR(GATT_OPERATION_IN_PROGRESS, NetworkError,
                 "GATT operation already in progress.");
       MAP_ERROR(UNTRANSLATED_CONNECT_ERROR_CODE, NetworkError,
                 "Unknown ConnectErrorCode.");
+      MAP_ERROR(GATT_SERVER_NOT_CONNECTED, NetworkError,
+                "GATT Server is disconnected. Cannot perform GATT operations.");
+      MAP_ERROR(GATT_SERVER_DISCONNECTED, NetworkError,
+                "GATT Server disconnected while performing a GATT operation.");
+      MAP_ERROR(GATT_SERVER_DISCONNECTED_WHILE_RETRIEVING_CHARACTERISTICS,
+                NetworkError,
+                "GATT Server disconnected while retrieving characteristics.");
+      MAP_ERROR(
+          GATT_SERVER_NOT_CONNECTED_CANNOT_RETRIEVE_CHARACTERISTICS,
+          NetworkError,
+          "GATT Server is disconnected. Cannot retrieve characteristics.");
 
       // NotFoundErrors:
       MAP_ERROR(WEB_BLUETOOTH_NOT_SUPPORTED, NotFoundError,
                 "Web Bluetooth is not supported on this platform. For a list "
                 "of supported platforms see: https://goo.gl/J6ASzs");
       MAP_ERROR(NO_BLUETOOTH_ADAPTER, NotFoundError,
                 "Bluetooth adapter not available.");
       MAP_ERROR(CHOSEN_DEVICE_VANISHED, NotFoundError,
                 "User selected a device that doesn't exist anymore.");
       MAP_ERROR(CHOOSER_CANCELLED, NotFoundError,
@@ skipping 58 matching lines @@
                 "requestDevice() called with a filter containing a blocklisted "
                 "UUID. https://goo.gl/4NeimX");
       MAP_ERROR(REQUEST_DEVICE_FROM_CROSS_ORIGIN_IFRAME, SecurityError,
                 "requestDevice() called from cross-origin iframe.");
       MAP_ERROR(REQUEST_DEVICE_WITHOUT_FRAME, SecurityError,
                 "No window to show the requestDevice() dialog.");
 
 #undef MAP_ERROR
   }
 
-  ASSERT_NOT_REACHED();
+  NOTREACHED();
   return DOMException::create(UnknownError);
 }
 
 }  // namespace blink