add preference clear - remove individual preference

lbry/extras/daemon/daemon.py

@@ -1151,6 +1151,25 @@ class Daemon(metaclass=JSONRPCServerType):
         wallet.save()
         return {key: value}
 
+    def jsonrpc_preference_clear(self, key, wallet_id=None):
+        """
+        Clear daemon preference
+
+        Usage:
+            preference_clear (<key>) [--wallet_id=<wallet_id>]
+
+        Options:
+            --key=<key> : (str) key associated with value
+            --wallet_id=<wallet_id>   : (str) restrict operation to specific wallet
+
+        Returns:
+            (dict) Updated dictionary of daemon preferences
+        """
+        wallet = self.wallet_manager.get_wallet_or_default(wallet_id)
+        del wallet.preferences[key]
+        wallet.save()
+        return wallet.preferences.to_dict_without_ts()
+
     WALLET_DOC = """
     Create, modify and inspect wallets.
     """

tests/integration/blockchain/test_wallet_commands.py

@@ -239,6 +239,14 @@ class WalletEncryptionAndSynchronization(CommandTestCase):
             {"one": "1", "two": "2", "conflict": "2", "another": "B", "fruit": ["peach", "apricot"]}
         )
 
+        daemon.jsonrpc_preference_clear("one")
+
+        self.assertDictEqual(
+            # "two" key added and "conflict" value changed to "2"
+            daemon.jsonrpc_preference_get(),
+            {"two": "2", "conflict": "2", "another": "B", "fruit": ["peach", "apricot"]}
+        )
+
         # Channel Certificate
         channel = await daemon2.jsonrpc_channel_create('@foo', '0.1')
         await self.confirm_tx(channel.id, self.daemon2.ledger)