consolidate Asset model in common

bigchaindb/common/transaction.py

@@ -10,7 +10,7 @@ from cryptoconditions.exceptions import ParsingError
 from bigchaindb.common.crypto import SigningKey, hash_data
 from bigchaindb.common.exceptions import (KeypairMismatchException,
                                           InvalidHash, InvalidSignature,
-                                          AmountError)
+                                          AmountError, AssetIdMismatch)
 from bigchaindb.common.util import serialize, gen_timestamp
 
 
@@ -306,7 +306,7 @@ class Condition(object):
             owners_after, threshold = owners_after
         else:
             threshold = len(owners_after)
-        
+
         if not isinstance(amount, int):
             raise TypeError('`amount` must be a int')
         if not isinstance(owners_after, list):
@@ -324,7 +324,7 @@ class Condition(object):
             initial_cond = ThresholdSha256Fulfillment(threshold=threshold)
             threshold_cond = reduce(cls._gen_condition, owners_after,
                                     initial_cond)
-            return cls(threshold_cond, owners_afteri, amount=amount)
+            return cls(threshold_cond, owners_after, amount=amount)
 
     @classmethod
     def _gen_condition(cls, initial, current):
@@ -469,6 +469,34 @@ class Asset(object):
         """Generates a unqiue uuid for an Asset"""
         return str(uuid4())
 
+    @staticmethod
+    def get_asset_id(transactions):
+        """Get the asset id from a list of transaction ids.
+
+        This is useful when we want to check if the multiple inputs of a transaction
+        are related to the same asset id.
+
+        Args:
+            transactions (list): list of transaction usually inputs that should have a matching asset_id
+
+        Returns:
+            str: uuid of the asset.
+
+        Raises:
+            AssetIdMismatch: If the inputs are related to different assets.
+        """
+
+        if not isinstance(transactions, list):
+            transactions = [transactions]
+
+        # create a set of asset_ids
+        asset_ids = {tx.asset.data_id for tx in transactions}
+
+        # check that all the transasctions have the same asset_id
+        if len(asset_ids) > 1:
+            raise AssetIdMismatch("All inputs of a transaction need to have the same asset id.")
+        return asset_ids.pop()
+
     def _validate_asset(self, amount=None):
         """Validates the asset"""
         if self.data is not None and not isinstance(self.data, dict):

bigchaindb/models.py

@@ -8,36 +8,6 @@ from bigchaindb.common.transaction import Transaction, Asset
 from bigchaindb.common.util import gen_timestamp, serialize
 
 
-class Asset(Asset):
-    @staticmethod
-    def get_asset_id(transactions):
-        """Get the asset id from a list of transaction ids.
-
-        This is useful when we want to check if the multiple inputs of a transaction
-        are related to the same asset id.
-
-        Args:
-            transactions (list): list of transaction usually inputs that should have a matching asset_id
-
-        Returns:
-            str: uuid of the asset.
-
-        Raises:
-            AssetIdMismatch: If the inputs are related to different assets.
-        """
-
-        if not isinstance(transactions, list):
-            transactions = [transactions]
-
-        # create a set of asset_ids
-        asset_ids = {tx.asset.data_id for tx in transactions}
-
-        # check that all the transasctions have the same asset_id
-        if len(asset_ids) > 1:
-            raise AssetIdMismatch("All inputs of a transaction need to have the same asset id.")
-        return asset_ids.pop()
-
-
 class Transaction(Transaction):
     def validate(self, bigchain):
         """Validate a transaction.
@@ -190,7 +160,7 @@ class Block(object):
 
     def is_signature_valid(self):
         block = self.to_dict()['block']
-        # cc only accepts bytesting messages 
+        # cc only accepts bytesting messages
         block_serialized = serialize(block).encode()
         verifying_key = VerifyingKey(block['node_pubkey'])
         try:

tests/assets/test_digital_assets.py

@@ -1,7 +1,7 @@
 import pytest
 from unittest.mock import patch
 
-from ..db.conftest import inputs
+from ..db.conftest import inputs  # noqa
 
 
 @pytest.mark.usefixtures('inputs')
@@ -171,7 +171,7 @@ def test_create_invalid_divisible_asset(b, user_vk, user_sk):
 
     # non divisible assets cannot have amount > 1
     # Transaction.__init__ should raise an exception
-    asset = Asset(divisible=False) 
+    asset = Asset(divisible=False)
     with pytest.raises(AmountError):
         Transaction.create([user_vk], [user_vk], asset=asset, amount=2)
 
@@ -202,7 +202,7 @@ def test_create_invalid_divisible_asset(b, user_vk, user_sk):
 
 def test_create_valid_divisible_asset(b, user_vk, user_sk):
     from bigchaindb.models import Transaction, Asset
-    
+
     asset = Asset(divisible=True)
     tx = Transaction.create([user_vk], [user_vk], asset=asset, amount=2)
     tx_signed = tx.sign([user_sk])