Handle errors to have cli output always be JSON

Handle HWWErrors generically when the command is invoked in
process_commands. The library functions that used to handle the
errors will instead raise the exceptions.

All exceptions possible are handled, with unknown ones resulting
in an UNKNOWN_ERROR code.

hwilib/cli.py

@@ -8,7 +8,8 @@ from .errors import (
     NO_DEVICE_PATH,
     DEVICE_CONN_ERROR,
     NO_PASSWORD,
-    UNKNWON_DEVICE_TYPE
+    UNKNWON_DEVICE_TYPE,
+    UNKNOWN_ERROR
 )
 
 import argparse
@@ -157,10 +158,8 @@ def process_commands(args):
     elif args.device_type and args.device_path:
         try:
             client = get_client(device_type, device_path, password)
-        except NoPasswordError as e:
+        except HWWError as e:
-            return {'error':str(e),'code':NO_PASSWORD}
+            return {'error': e.get_msg(), 'code': e.get_code()}
-        except UnknownDeviceError as e:
-            return {'error':str(e),'code':UNKNWON_DEVICE_TYPE}
         except Exception as e:
             return {'error':str(e),'code':DEVICE_CONN_ERROR}
     else:
@@ -169,10 +168,26 @@ def process_commands(args):
     client.is_testnet = args.testnet
 
     # Do the commands
-    result = args.func(args, client)
+    try:
+        result = args.func(args, client)
+    except HWWError as e:
+        result = {'error': e.get_msg(), 'code': e.get_code()}
+    except Exception as e:
+        if args.debug:
+            import traceback
+            traceback.print_exc()
+        result = {'error': str(e), 'code': UNKNOWN_ERROR}
 
     # Close the device
-    client.close()
+    try:
+        client.close()
+    except HWWError as e:
+        result = {'error': e.get_msg(), 'code': e.get_code()}
+    except Exception as e:
+        if args.debug:
+            import traceback
+            traceback.print_exc()
+        result = {'error': str(e), 'code': UNKNOWN_ERROR}
 
     return result
 

hwilib/commands.py

@@ -66,37 +66,19 @@ def find_device(device_path, password='', device_type=None, fingerprint=None):
     return None
 
 def getmasterxpub(client):
-    try:
+    return client.get_master_xpub()
-        return client.get_master_xpub()
-    except NotImplementedError as e:
-        return {'error': str(e), 'code': NOT_IMPLEMENTED}
 
 def signtx(client, psbt):
     # Deserialize the transaction
-    try:
+    tx = PSBT()
-        tx = PSBT()
+    tx.deserialize(psbt)
-        tx.deserialize(psbt)
+    return client.sign_tx(tx)
-        return client.sign_tx(tx)
-    except NotImplementedError as e:
-        return {'error': str(e), 'code': NOT_IMPLEMENTED}
-    except IOError as e:
-        return {'error':'You must provide a PSBT','code':INVALID_TX}
-    except Exception as e:
-        return {'error': str(e), 'code': BAD_ARGUMENT}
 
 def getxpub(client, path):
-    try:
+    return client.get_pubkey_at_path(path)
-        return client.get_pubkey_at_path(path)
-    except NotImplementedError as e:
-        return {'error': str(e), 'code': NOT_IMPLEMENTED}
 
 def signmessage(client, message, path):
-    try:
+    return client.sign_message(message, path)
-        return client.sign_message(message, path)
-    except NotImplementedError as e:
-        return {'error': str(e), 'code': NOT_IMPLEMENTED}
-    except ValueError as e:
-        return {'error': str(e), 'code': BAD_ARGUMENT}
 
 def getkeypool(client, path, start, end, internal=False, keypool=False, account=0, sh_wpkh=False, wpkh=True):
     if sh_wpkh == True and wpkh == True:
@@ -178,49 +160,19 @@ def displayaddress(client, path, sh_wpkh=False, wpkh=False):
     return client.display_address(path, sh_wpkh, wpkh)
 
 def setup_device(client, label='', backup_passphrase=''):
-    try:
+    return client.setup_device(label, backup_passphrase)
-        return client.setup_device(label, backup_passphrase)
-    except UnavailableActionError as e:
-        return {'error': str(e), 'code': UNAVAILABLE_ACTION}
-    except DeviceAlreadyInitError as e:
-        return {'error': str(e), 'code': DEVICE_ALREADY_INIT}
-    except ValueError as e:
-        return {'error': str(e), 'code': BAD_ARGUMENT}
 
 def wipe_device(client):
-    try:
+    return client.wipe_device()
-        return client.wipe_device()
-    except UnavailableActionError as e:
-        return {'error': str(e), 'code': UNAVAILABLE_ACTION}
 
 def restore_device(client, label):
-    try:
+    return client.restore_device(label)
-        return client.restore_device(label)
-    except UnavailableActionError as e:
-        return {'error': str(e), 'code': UNAVAILABLE_ACTION}
-    except DeviceAlreadyInitError as e:
-        return {'error': str(e), 'code': DEVICE_ALREADY_INIT}
-    except ValueError as e:
-        return {'error': str(e), 'code': BAD_ARGUMENT}
 
 def backup_device(client, label='', backup_passphrase=''):
-    try:
+    return client.backup_device(label, backup_passphrase)
-        return client.backup_device(label, backup_passphrase)
-    except UnavailableActionError as e:
-        return {'error': str(e), 'code': UNAVAILABLE_ACTION}
-    except ValueError as e:
-        return {'error': str(e), 'code': BAD_ARGUMENT}
 
 def prompt_pin(client):
-    try:
+    return client.prompt_pin()
-        return client.prompt_pin()
-    except DeviceAlreadyUnlockedError as e:
-        return {'error': str(e), 'code': DEVICE_ALREADY_UNLOCKED}
 
 def send_pin(client, pin):
-    try:
+    return client.send_pin(pin)
-        return client.send_pin(pin)
-    except DeviceAlreadyUnlockedError as e:
-        return {'error': str(e), 'code': DEVICE_ALREADY_UNLOCKED}
-    except ValueError as e:
-        return {'error': str(e), 'code': BAD_ARGUMENT}

hwilib/devices/trezor.py

@@ -95,7 +95,10 @@ class TrezorClient(HardwareWalletClient):
     # Retrieves the public key at the specified BIP 32 derivation path
     def get_pubkey_at_path(self, path):
         self._check_unlocked()
-        expanded_path = tools.parse_path(path)
+        try:
+            expanded_path = tools.parse_path(path)
+        except ValueError as e:
+            raise BadArgumentError(str(e))
         output = btc.get_public_node(self.client, expanded_path)
         if self.is_testnet:
             return {'xpub':xpub_main_2_test(output.xpub)}