Move pytest fixtures to importable location, add allowance check for transfer from

apps/cic-eth/cic_eth/api/api_task.py

@@ -204,6 +204,82 @@ class Api:
 #        return t
 
 
+    def transfer_from(self, from_address, to_address, value, token_symbol, spender_address):
+        """Executes a chain of celery tasks that performs a transfer of ERC20 tokens by one address on behalf of another address to a third party.
+
+        :param from_address: Ethereum address of sender
+        :type from_address: str, 0x-hex
+        :param to_address: Ethereum address of recipient
+        :type to_address: str, 0x-hex
+        :param value: Estimated return from conversion
+        :type  value: int
+        :param token_symbol: ERC20 token symbol of token to send
+        :type token_symbol: str
+        :param spender_address: Ethereum address of recipient
+        :type spender_address: str, 0x-hex
+        :returns: uuid of root task
+        :rtype: celery.Task
+        """
+        s_check = celery.signature(
+                'cic_eth.admin.ctrl.check_lock',
+                [
+                    [token_symbol],
+                    self.chain_spec.asdict(),
+                    LockEnum.QUEUE,
+                    from_address,
+                    ],
+                queue=self.queue,
+                )
+        s_nonce = celery.signature(
+                'cic_eth.eth.nonce.reserve_nonce',
+                [
+                    self.chain_spec.asdict(),
+                    from_address,
+                    ],
+                queue=self.queue,
+                )
+        s_tokens = celery.signature(
+                'cic_eth.eth.erc20.resolve_tokens_by_symbol',
+                [
+                    self.chain_spec.asdict(),
+                    ],
+                queue=self.queue,
+                )
+        s_allow = celery.signature(
+                'cic_eth.eth.erc20.check_allowance',
+                [
+                    from_address,
+                    value,
+                    self.chain_spec.asdict(),
+                    spender_address,
+                    ],
+                queue=self.queue,
+                )
+        s_transfer = celery.signature(
+                'cic_eth.eth.erc20.transfer_from',
+                [
+                    from_address,
+                    to_address,
+                    value,
+                    self.chain_spec.asdict(),
+                    spender_address,
+                    ],
+                queue=self.queue,
+                )
+        s_tokens.link(s_allow)
+        s_nonce.link(s_tokens)
+        s_check.link(s_nonce)
+        if self.callback_param != None:
+            s_transfer.link(self.callback_success)
+            s_allow.link(s_transfer).on_error(self.callback_error)
+        else:
+            s_allow.link(s_transfer)
+
+        t = s_check.apply_async(queue=self.queue)
+        return t
+
+
+
     def transfer(self, from_address, to_address, value, token_symbol):
         """Executes a chain of celery tasks that performs a transfer of ERC20 tokens from one address to another.
 

apps/cic-eth/cic_eth/error.py

@@ -80,3 +80,8 @@ class SignerError(SeppukuError):
 class RoleAgencyError(SeppukuError):
     """Exception raise when a role cannot perform its function. This is a critical exception
     """
+
+
+class YouAreBrokeError(Exception):
+    """Exception raised when a value transfer is attempted without access to sufficient funds
+    """

apps/cic-eth/cic_eth/eth/erc20.py

@@ -24,6 +24,7 @@ from cic_eth.error import (
         TokenCountError,
         PermanentTxError,
         OutOfGasError,
+        YouAreBrokeError,
         )
 from cic_eth.queue.tx import register_tx
 from cic_eth.eth.gas import (
@@ -71,6 +72,117 @@ def balance(tokens, holder_address, chain_spec_dict):
     return tokens
 
 
+@celery_app.task(bind=True)
+def check_allowance(self, tokens, holder_address, value, chain_spec_dict, spender_address):
+    """Best-effort verification that the allowance for a transfer from spend is sufficient.
+
+    :raises YouAreBrokeError: If allowance is insufficient
+    
+    :param tokens: Token addresses 
+    :type tokens: list of str, 0x-hex
+    :param holder_address: Token holder address
+    :type holder_address: str, 0x-hex
+    :param value: Amount of token, in 'wei'
+    :type value: int
+    :param chain_str: Chain spec string representation
+    :type chain_str: str
+    :param spender_address: Address of account spending on behalf of holder
+    :type spender_address: str, 0x-hex
+    :return: Token list as passed to task
+    :rtype: dict
+    """
+    logg.debug('tokens {}'.format(tokens))
+    if len(tokens) != 1:
+        raise TokenCountError
+    t = tokens[0]
+    chain_spec = ChainSpec.from_dict(chain_spec_dict)
+
+    rpc = RPCConnection.connect(chain_spec, 'default')
+
+    caller_address = ERC20Token.caller_address 
+    c = ERC20(chain_spec)
+    o = c.allowance(t['address'], holder_address, spender_address, sender_address=caller_address)
+    r = rpc.do(o)
+    allowance = c.parse_allowance(r)
+    if allowance < value:
+        errstr = 'allowance {} insufficent to transfer {} {} by {} on behalf of {}'.format(allowance, value, t['symbol'], spender_address, holder_address)
+        logg.error(errstr)
+        raise YouAreBrokeError(errstr)
+
+    return tokens
+
+
+@celery_app.task(bind=True, base=CriticalSQLAlchemyAndSignerTask)
+def transfer_from(self, tokens, holder_address, receiver_address, value, chain_spec_dict, spender_address):
+    """Transfer ERC20 tokens between addresses
+
+    First argument is a list of tokens, to enable the task to be chained to the symbol to token address resolver function. However, it accepts only one token as argument.
+
+    :param tokens: Token addresses 
+    :type tokens: list of str, 0x-hex
+    :param holder_address: Token holder address
+    :type holder_address: str, 0x-hex
+    :param receiver_address: Token receiver address
+    :type receiver_address: str, 0x-hex
+    :param value: Amount of token, in 'wei'
+    :type value: int
+    :param chain_str: Chain spec string representation
+    :type chain_str: str
+    :param spender_address: Address of account spending on behalf of holder
+    :type spender_address: str, 0x-hex
+    :raises TokenCountError: Either none or more then one tokens have been passed as tokens argument
+    :return: Transaction hash for tranfer operation
+    :rtype: str, 0x-hex
+    """
+    # we only allow one token, one transfer
+    logg.debug('tokens {}'.format(tokens))
+    if len(tokens) != 1:
+        raise TokenCountError
+    t = tokens[0]
+    chain_spec = ChainSpec.from_dict(chain_spec_dict)
+    queue = self.request.delivery_info.get('routing_key')
+
+    rpc = RPCConnection.connect(chain_spec, 'default')
+    rpc_signer = RPCConnection.connect(chain_spec, 'signer')
+
+    session = self.create_session()
+    nonce_oracle = CustodialTaskNonceOracle(holder_address, self.request.root_id, session=session)
+    gas_oracle = self.create_gas_oracle(rpc, MaxGasOracle.gas)
+    c = ERC20(chain_spec, signer=rpc_signer, gas_oracle=gas_oracle, nonce_oracle=nonce_oracle)
+    try:
+        (tx_hash_hex, tx_signed_raw_hex) = c.transfer_from(t['address'], spender_address, holder_address, receiver_address, value, tx_format=TxFormat.RLP_SIGNED)
+    except FileNotFoundError as e:
+        raise SignerError(e)
+    except ConnectionError as e:
+        raise SignerError(e)
+    
+
+    rpc_signer.disconnect()
+    rpc.disconnect()
+
+    cache_task = 'cic_eth.eth.erc20.cache_transfer_from_data'
+
+    register_tx(tx_hash_hex, tx_signed_raw_hex, chain_spec, queue, cache_task=cache_task, session=session)
+    session.commit()
+    session.close()
+    
+    gas_pair = gas_oracle.get_gas(tx_signed_raw_hex)
+    gas_budget = gas_pair[0] * gas_pair[1]
+    logg.debug('transfer tx {} {} {}'.format(tx_hash_hex, queue, gas_budget))
+
+    s = create_check_gas_task(
+             [tx_signed_raw_hex],
+             chain_spec,
+             holder_address,
+             gas_budget,
+             [tx_hash_hex],
+             queue,
+            )
+    s.apply_async()
+    return tx_hash_hex
+
+
+
 @celery_app.task(bind=True, base=CriticalSQLAlchemyAndSignerTask)
 def transfer(self, tokens, holder_address, receiver_address, value, chain_spec_dict):
     """Transfer ERC20 tokens between addresses
@@ -232,6 +344,7 @@ def resolve_tokens_by_symbol(self, token_symbols, chain_spec_dict):
         logg.debug('token {}'.format(token_address))
         tokens.append({
             'address': token_address,
+            'symbol': token_symbol,
             'converters': [],
             })
     rpc.disconnect()
@@ -279,6 +392,48 @@ def cache_transfer_data(
     return (tx_hash_hex, cache_id)
 
 
+@celery_app.task(base=CriticalSQLAlchemyTask)
+def cache_transfer_from_data(
+    tx_hash_hex,
+    tx_signed_raw_hex,
+    chain_spec_dict,
+        ):
+    """Helper function for otx_cache_transfer_from
+
+    :param tx_hash_hex: Transaction hash
+    :type tx_hash_hex: str, 0x-hex
+    :param tx: Signed raw transaction
+    :type tx: str, 0x-hex
+    :returns: Transaction hash and id of cache element in storage backend, respectively
+    :rtype: tuple
+    """
+    chain_spec = ChainSpec.from_dict(chain_spec_dict)
+    tx_signed_raw_bytes = bytes.fromhex(strip_0x(tx_signed_raw_hex))
+    tx = unpack(tx_signed_raw_bytes, chain_spec)
+
+    tx_data = ERC20.parse_transfer_from_request(tx['data'])
+    spender_address = tx_data[0]
+    recipient_address = tx_data[1]
+    token_value = tx_data[2]
+
+    session = SessionBase.create_session()
+    tx_cache = TxCache(
+        tx_hash_hex,
+        tx['from'],
+        recipient_address,
+        tx['to'],
+        tx['to'],
+        token_value,
+        token_value,
+        session=session,
+            )
+    session.add(tx_cache)
+    session.commit()
+    cache_id = tx_cache.id
+    session.close()
+    return (tx_hash_hex, cache_id)
+
+
 @celery_app.task(base=CriticalSQLAlchemyTask)
 def cache_approve_data(
     tx_hash_hex,

apps/cic-eth/cic_eth/pytest/fixtures_config.py

@@ -2,13 +2,13 @@
 import os
 import logging
 
-# third-party imports
+# external imports
 import pytest
 import confini
 
 script_dir = os.path.dirname(os.path.realpath(__file__))
-root_dir = os.path.dirname(script_dir)
-logg = logging.getLogger(__file__)
+root_dir = os.path.dirname(os.path.dirname(script_dir))
+logg = logging.getLogger(__name__)
 
 
 @pytest.fixture(scope='session')

apps/cic-eth/cic_eth/pytest/fixtures_database.py

@@ -37,7 +37,8 @@ def init_database(
         database_engine,
         ):
 
-    rootdir = os.path.dirname(os.path.dirname(__file__))
+    script_dir = os.path.dirname(os.path.realpath(__file__))
+    rootdir = os.path.dirname(os.path.dirname(script_dir))
     dbdir = os.path.join(rootdir, 'cic_eth', 'db')
     migrationsdir = os.path.join(dbdir, 'migrations', load_config.get('DATABASE_ENGINE'))
     if not os.path.isdir(migrationsdir):

apps/cic-eth/tests/conftest.py

@@ -17,11 +17,11 @@ root_dir = os.path.dirname(script_dir)
 sys.path.insert(0, root_dir)
 
 # assemble fixtures
-from tests.fixtures_config import *
-from tests.fixtures_database import *
-from tests.fixtures_celery import *
-from tests.fixtures_role import *
-from tests.fixtures_contract import *
+from cic_eth.pytest.fixtures_config import *
+from cic_eth.pytest.fixtures_celery import *
+from cic_eth.pytest.fixtures_database import *
+from cic_eth.pytest.fixtures_role import *
+from cic_eth.pytest.fixtures_contract import *
 from chainlib.eth.pytest import *
 from eth_contract_registry.pytest import *
 from cic_eth_registry.pytest.fixtures_contracts import *