Keep fixtures up to date with registry changes; Deprecate or relocate some test utilities.

nucypher/blockchain/eth/utilities.py

@@ -0,0 +1,68 @@
+import os
+import tempfile
+
+import pkg_resources
+from eth_tester import PyEVMBackend
+from eth_tester.backends import is_pyevm_available
+from eth_tester.backends.pyevm.main import get_default_genesis_params, get_default_account_keys, generate_genesis_state
+
+from nucypher.blockchain.eth.interfaces import EthereumContractRegistry
+
+
+class TemporaryEthereumContractRegistry(EthereumContractRegistry):
+
+    def __init__(self):
+        _, self.temp_filepath = tempfile.mkstemp()
+        super().__init__(registry_filepath=self.temp_filepath)
+
+    def clear(self):
+        with open(self.registry_filepath, 'w') as registry_file:
+            registry_file.write('')
+
+    def reset(self):
+        os.remove(self.temp_filepath)  # remove registrar tempfile
+
+
+class OverridablePyEVMBackend(PyEVMBackend):
+
+    def __init__(self, genesis_overrides=None):
+        """
+        Example overrides
+        ---------------------------------
+        coinbase: address_bytes
+        difficulty: int(default: 131072)
+        extra_data: bytes
+        gas_limit: int(default: 3141592)
+        gas_used: int(default: 0)
+        nonce: bytes
+        block_number: int
+        timestamp: int(epoch)
+        """
+
+        self.fork_config = dict()
+
+        if not is_pyevm_available():
+            raise pkg_resources.DistributionNotFound(
+                "The `py-evm` package is not available.  The "
+                "`PyEVMBackend` requires py-evm to be installed and importable. "
+                "Please install the `py-evm` library."
+            )
+
+        self.reset_to_genesis(overrides=genesis_overrides)
+
+    def reset_to_genesis(self, overrides=None):
+        from evm.chains.tester import MainnetTesterChain
+        from evm.db import get_db_backend
+
+        base_db = get_db_backend()
+        genesis_params = get_default_genesis_params()
+
+        # Genesis params overrides
+        if overrides is not None:
+            genesis_params.update(overrides)
+
+        account_keys = get_default_account_keys()
+        genesis_state = generate_genesis_state(account_keys)
+        chain = MainnetTesterChain.from_genesis(base_db, genesis_params, genesis_state)
+
+        self.account_keys, self.chain = account_keys, chain

tests/blockchain/eth/entities/test_deployers.py

@@ -36,6 +36,8 @@ def test_token_deployer_and_agent(testerchain):
     assert token_agent.contract_address == same_token_agent.contract_address
     assert token_agent == same_token_agent  # __eq__
 
+    testerchain.interface._registry.clear()
+
 
 @pytest.mark.slow()
 def test_deploy_ethereum_contracts(testerchain):

tests/blockchain/eth/utilities.py

@@ -1,15 +1,11 @@
 import random
 from typing import List
 
-import pkg_resources
 from constant_sorrow import constants
-from eth_tester import PyEVMBackend
-from eth_tester.backends import is_pyevm_available
-from eth_tester.backends.pyevm.main import get_default_genesis_params, get_default_account_keys, generate_genesis_state
 from umbral import keys
 from web3 import Web3
 
-from nucypher.blockchain.eth.agents import MinerAgent, NucypherTokenAgent
+from nucypher.blockchain.eth.agents import MinerAgent
 from nucypher.blockchain.eth.deployers import MinerEscrowDeployer, NucypherTokenDeployer
 
 
@@ -73,64 +69,3 @@ def generate_accounts(w3: Web3, quantity: int) -> List[str]:
         w3.personal.unlockAccount(address, passphrase=insecure_passphrase)
         addresses.append(addresses)
     return addresses
-
-
-class TesterPyEVMBackend(PyEVMBackend):
-
-    def __init__(self, genesis_overrides=None):
-        """
-        Example overrides
-        ---------------------------------
-        coinbase: address_bytes
-        difficulty: int(default: 131072)
-        extra_data: bytes
-        gas_limit: int(default: 3141592)
-        gas_used: int(default: 0)
-        nonce: bytes
-        block_number: int
-        timestamp: int(epoch)
-        """
-
-        self.fork_config = dict()
-
-        if not is_pyevm_available():
-            raise pkg_resources.DistributionNotFound(
-                "The `py-evm` package is not available.  The "
-                "`PyEVMBackend` requires py-evm to be installed and importable. "
-                "Please install the `py-evm` library."
-            )
-
-        self.reset_to_genesis(overrides=genesis_overrides)
-
-    def reset_to_genesis(self, overrides=None):
-        from evm.chains.tester import MainnetTesterChain
-        from evm.db import get_db_backend
-
-        base_db = get_db_backend()
-        genesis_params = get_default_genesis_params()
-
-        # Genesis params overrides
-        if overrides is not None:
-            genesis_params.update(overrides)
-
-        account_keys = get_default_account_keys()
-        genesis_state = generate_genesis_state(account_keys)
-        chain = MainnetTesterChain.from_genesis(base_db, genesis_params, genesis_state)
-
-        self.account_keys, self.chain = account_keys, chain
-
-
-def token_airdrop(token_agent, amount: int, origin: str, addresses: List[str]):
-    """Airdrops tokens from creator address to all other addresses!"""
-
-    def txs():
-        for address in addresses:
-            txhash = token_agent.contract.functions.transfer(address, amount).transact({'from': origin,
-                                                                                 'gas': 2000000})
-            yield txhash
-
-    receipts = list()
-    for tx in txs():    # One at a time
-        receipt = token_agent.blockchain.wait_for_receipt(tx)
-        receipts.append(receipt)
-    return receipts

tests/eth_fixtures.py

@@ -118,22 +118,18 @@ def testerchain(solidity_compiler):
     https: // github.com / ethereum / eth - tester     # available-backends
     """
 
-    # create a temporary registrar for the tester blockchain
-    _, filepath = tempfile.mkstemp()
-    test_registrar = EthereumContractRegistry(registry_filepath=filepath)
+    temp_registrar = TemporaryEthereumContractRegistry()
 
     # Configure a custom provider
     overrides = {'gas_limit': 4626271}
-    pyevm_backend = TesterPyEVMBackend(genesis_overrides=overrides)
-
-    # pyevm_backend = PyEVMBackend() # TODO: Remove custom overrides?
+    pyevm_backend = OverridablePyEVMBackend(genesis_overrides=overrides)
 
     eth_tester = EthereumTester(backend=pyevm_backend, auto_mine_transactions=True)
     pyevm_provider = EthereumTesterProvider(ethereum_tester=eth_tester)
 
     # Use the the custom provider and registrar to init an interface
     circumflex = DeployerCircumflex(compiler=solidity_compiler,    # freshly recompile
-                                    registry=test_registrar,      # use temporary registrar
+                                    registry=temp_registrar,       # use temporary registrar
                                     providers=(pyevm_provider, ))  # use custom test provider
 
     # Create the blockchain
@@ -143,8 +139,7 @@ def testerchain(solidity_compiler):
 
     yield testerchain
 
-    testerchain.sever_connection()  # Destroy the blockchin singelton cache
-    os.remove(filepath)             # remove registrar tempfile
+    testerchain.sever_connection()
 
 
 #