handles importing of test packages in production builds

nucypher/blockchain/eth/interfaces.py

@@ -8,16 +8,9 @@ import requests
 from atxm import AutomaticTxMachine
 from atxm.tx import AsyncTx
 from constant_sorrow.constants import (
-    INSUFFICIENT_FUNDS,
-    NO_BLOCKCHAIN_CONNECTION,
-    UNKNOWN_TX_STATUS,
-)
-from eth_tester import EthereumTester
-from eth_tester.exceptions import (
-    TransactionFailed as TestTransactionFailed,
-)
-from eth_tester.exceptions import (
-    ValidationError,
+    INSUFFICIENT_FUNDS,  # noqa
+    NO_BLOCKCHAIN_CONNECTION,  # noqa
+    UNKNOWN_TX_STATUS,  # noqa
 )
 from eth_utils import to_checksum_address
 from hexbytes.main import HexBytes
@@ -50,7 +43,7 @@ from nucypher.utilities.gas_strategies import (
 from nucypher.utilities.logging import Logger
 
 Web3Providers = Union[
-    IPCProvider, WebsocketProvider, HTTPProvider, EthereumTester
+    IPCProvider, WebsocketProvider, HTTPProvider
 ]  # TODO: Move to types.py
 
 
@@ -540,7 +533,7 @@ class BlockchainInterface:
                     payload, block_identifier="latest"
                 )
             transaction_dict = contract_function.build_transaction(payload)
-        except (TestTransactionFailed, ValidationError, ValueError) as error:
+        except ValueError as error:
             # Note: Geth (1.9.15) raises ValueError in the same condition that pyevm raises ValidationError here.
             # Treat this condition as "Transaction Failed" during gas estimation.
             raise self._handle_failed_transaction(
@@ -610,7 +603,7 @@ class BlockchainInterface:
                 signed_transaction.rawTransaction
             )  # <--- BROADCAST
             emitter.message(f"TXHASH {txhash.hex()}", color="yellow")
-        except (TestTransactionFailed, ValueError):
+        except ValueError:
             raise  # TODO: Unify with Transaction failed handling -- Entry point for _handle_failed_transaction
 
         #

nucypher/blockchain/eth/providers.py

@@ -1,11 +1,7 @@
-from typing import Union
 from urllib.parse import urlparse
 
-from eth_tester import EthereumTester, PyEVMBackend
-from eth_tester.backends.mock.main import MockBackend
 from web3 import HTTPProvider, IPCProvider, WebsocketProvider
 from web3.providers import BaseProvider
-from web3.providers.eth_tester.main import EthereumTesterProvider
 
 from nucypher.exceptions import DevelopmentInstallationRequired
 
@@ -49,7 +45,8 @@ def _get_auto_provider(endpoint) -> BaseProvider:
     return w3.provider
 
 
-def _get_pyevm_test_backend() -> PyEVMBackend:
+def _get_pyevm_test_backend():
+
     try:
         # TODO: Consider packaged support of --dev mode with testerchain
         from tests.constants import NUMBER_OF_ETH_TEST_ACCOUNTS, PYEVM_GAS_LIMIT
@@ -57,13 +54,21 @@ def _get_pyevm_test_backend() -> PyEVMBackend:
         raise DevelopmentInstallationRequired(importable_name='tests.constants')
 
     # Initialize
+    from eth_tester import PyEVMBackend
     genesis_params = PyEVMBackend._generate_genesis_params(overrides={'gas_limit': PYEVM_GAS_LIMIT})
     pyevm_backend = PyEVMBackend(genesis_parameters=genesis_params)
     pyevm_backend.reset_to_genesis(genesis_params=genesis_params, num_accounts=NUMBER_OF_ETH_TEST_ACCOUNTS)
     return pyevm_backend
 
 
-def _get_ethereum_tester(test_backend: Union[PyEVMBackend, MockBackend]) -> EthereumTesterProvider:
+def _get_ethereum_tester(test_backend):
+    try:
+        from eth_tester import EthereumTester
+        from web3.providers.eth_tester.main import EthereumTesterProvider
+    except ImportError:
+        raise DevelopmentInstallationRequired(
+            importable_name="web3.providers.eth_tester"
+        )
     eth_tester = EthereumTester(backend=test_backend, auto_mine_transactions=True)
     provider = EthereumTesterProvider(ethereum_tester=eth_tester)
     return provider
@@ -79,6 +84,10 @@ def _get_pyevm_test_provider(endpoint) -> BaseProvider:
 
 def _get_mock_test_provider(endpoint) -> BaseProvider:
     # https://github.com/ethereum/eth-tester#mockbackend
+    try:
+        from eth_tester import MockBackend
+    except ImportError:
+        raise DevelopmentInstallationRequired(importable_name="eth_tester.MockBackend")
     mock_backend = MockBackend()
     provider = _get_ethereum_tester(test_backend=mock_backend)
     return provider

nucypher/characters/unlawful.py

@@ -2,7 +2,6 @@ from copy import copy
 from unittest import mock
 from unittest.mock import Mock, patch
 
-from eth_tester.exceptions import ValidationError
 from nucypher_core import NodeMetadata
 
 from nucypher.blockchain.eth.signers.software import Web3Signer
@@ -120,6 +119,12 @@ class Vladimir(Ursula):
         """
         Upload Vladimir's ETH keys to the keychain via web3.
         """
+        try:
+            from eth_tester.exceptions import ValidationError
+        except ImportError:
+            raise DevelopmentInstallationRequired(
+                importable_name="eth_tester.exceptions.ValidationError"
+            )
         try:
             password = 'iamverybadass'
             blockchain.w3.provider.ethereum_tester.add_account(cls.fraud_key, password=password)