Updates to test suite after running for EELS backend

Author: fselmo

conftest.py

@@ -3,7 +3,6 @@
 import warnings
 
 from eth_tester import (
-    EELSBackend,
     EthereumTester,
 )
 import pytest_asyncio
@@ -75,17 +74,15 @@ def _wait_for_transaction(w3, txn_hash, timeout=120):
 
 
 @pytest.fixture
-def w3():
-    t = EthereumTester(backend=EELSBackend("cancun"))
-    w3 = Web3(EthereumTesterProvider(t))
+def w3(backend_class):
+    w3 = Web3(EthereumTesterProvider(EthereumTester(backend=backend_class())))
     w3.eth.default_account = w3.eth.accounts[0]
     return w3
 
 
 @pytest.fixture(scope="module")
-def w3_non_strict_abi():
-    t = EthereumTester(backend=EELSBackend("cancun"))
-    w3 = Web3(EthereumTesterProvider(t))
+def w3_non_strict_abi(backend_class):
+    w3 = Web3(EthereumTesterProvider(EthereumTester(backend=backend_class())))
     w3.eth.default_account = w3.eth.accounts[0]
     w3.strict_bytes_type_checking = False
     return w3

setup.py

@@ -4,11 +4,15 @@
     setup,
 )
 
+CUSTOM_ETH_TESTER_BRANCH = " @ git+https://github.com/fselmo/eth-tester@eels-backend"
+
 extras_require = {
     "tester": [
         # Note: ethereum-maintained libraries in this list should be added to the
         # `install_pre_releases.py` script.
-        "eth-tester[py-evm]>=0.13.0b1,<0.14.0b1",
+        f"eth-tester[py-evm]{CUSTOM_ETH_TESTER_BRANCH}",
+        # if python version >= 3.10, install the eels backend:
+        f"eth-tester[eels]{CUSTOM_ETH_TESTER_BRANCH} ; python_version >= '3.10'",
         "py-geth>=5.1.0",
     ],
     "dev": [

tests/conftest.py

@@ -3,6 +3,9 @@
     Type,
 )
 
+from eth_tester import (
+    PyEVMBackend,
+)
 from eth_utils import (
     event_signature_to_log_topic,
     to_bytes,
@@ -19,6 +22,8 @@
     RequestMocker,
 )
 
+SUPPORTED_ETH_TESTER_BACKENDS = {"pyevm", "eels"}
+
 
 @pytest.fixture(scope="module", params=[lambda x: to_bytes(hexstr=x), identity])
 def address_conversion_func(request):
@@ -28,6 +33,47 @@ def address_conversion_func(request):
 # --- session-scoped constants --- #
 
 
+def pytest_addoption(parser):
+    parser.addoption(
+        "--backend",
+        action="store",
+        default=None,
+        help="Specify the backend for `EthereumTester` to use.",
+    )
+
+
+def pytest_collection_modifyitems(config, items):
+    backend_required_for_tests = any(
+        "backend_class" in item.fixturenames for item in items
+    )
+    if backend_required_for_tests:
+        backend = config.getoption("--backend")
+        if not backend:
+            raise pytest.UsageError(
+                "This test run requires a specified a backend via the `--backend` "
+                "command line option. Supported backends are: "
+                f"{SUPPORTED_ETH_TESTER_BACKENDS}"
+            )
+        elif backend not in SUPPORTED_ETH_TESTER_BACKENDS:
+            raise pytest.UsageError(f"Unsupported backend: `{backend}`.")
+
+
+@pytest.fixture(scope="session")
+def backend_class(request):
+    backend = request.config.getoption("--backend")
+    if backend == "pyevm":
+        return PyEVMBackend
+    elif backend == "eels":
+        # conditionally import since eels is only supported on python >= 3.10
+        from eth_tester.backends.eels import (
+            EELSBackend,
+        )
+
+        return EELSBackend
+    else:
+        raise ValueError("Invariant: Unreachable code path.")
+
+
 @pytest.fixture(scope="session")
 def emitter_contract_data():
     return EMITTER_CONTRACT_DATA

tests/core/conftest.py

@@ -1,7 +1,6 @@
 import pytest
 
 from eth_tester import (
-    EELSBackend,
     EthereumTester,
 )
 import pytest_asyncio
@@ -121,19 +120,16 @@ def __init__(self, a, b):
 
 
 @pytest_asyncio.fixture
-async def async_w3():
-    t = EthereumTester(backend=EELSBackend("cancun"))
-    provider = AsyncEthereumTesterProvider()
-    provider.ethereum_tester = t
-    w3 = AsyncWeb3(provider)
+async def async_w3(backend_class):
+    w3 = AsyncWeb3(AsyncEthereumTesterProvider(EthereumTester(backend=backend_class())))
     accounts = await w3.eth.accounts
     w3.eth.default_account = accounts[0]
     return w3
 
 
 @pytest_asyncio.fixture
-async def async_w3_non_strict_abi():
-    w3 = AsyncWeb3(AsyncEthereumTesterProvider())
+async def async_w3_non_strict_abi(backend_class):
+    w3 = AsyncWeb3(AsyncEthereumTesterProvider(EthereumTester(backend=backend_class())))
     w3.strict_bytes_type_checking = False
     accounts = await w3.eth.accounts
     w3.eth.default_account = accounts[0]

tests/core/contracts/test_contract_attributes.py

@@ -6,7 +6,7 @@
 )
 
 
-@pytest.fixture()
+@pytest.fixture
 def abi():
     return """[{"anonymous":false,"inputs":[{"indexed":false,"name":"value","type":"uint256"}],"name":"Increased","type":"function"}, {"anonymous":false,"inputs":[{"indexed":false,"name":"value","type":"uint256"}],"name":"Increased","type":"event"}]"""  # noqa: E501
 

tests/core/contracts/test_contract_caller_interface.py

@@ -8,12 +8,12 @@
 )
 
 
-@pytest.fixture()
+@pytest.fixture
 def address(w3):
     return w3.eth.accounts[1]
 
 
-@pytest.fixture()
+@pytest.fixture
 def transaction_dict(w3, address):
     return {
         "from": address,

tests/core/contracts/test_contract_example.py

@@ -2,6 +2,9 @@
 # of how to write unit tests with web3.py
 import pytest
 
+from eth_tester import (
+    EthereumTester,
+)
 import pytest_asyncio
 
 from web3 import (
@@ -15,8 +18,8 @@
 
 
 @pytest.fixture
-def tester_provider():
-    return EthereumTesterProvider()
+def tester_provider(backend_class):
+    return EthereumTesterProvider(EthereumTester(backend=backend_class()))
 
 
 @pytest.fixture
@@ -118,8 +121,10 @@ def async_eth_tester():
 
 
 @pytest_asyncio.fixture()
-async def async_w3():
-    async_w3 = AsyncWeb3(AsyncEthereumTesterProvider())
+async def async_w3(backend_class):
+    async_w3 = AsyncWeb3(
+        AsyncEthereumTesterProvider(EthereumTester(backend=backend_class()))
+    )
     accounts = await async_w3.eth.accounts
     async_w3.eth.default_account = accounts[0]
     return async_w3

tests/core/contracts/test_contract_init.py

@@ -11,7 +11,7 @@
 )
 
 
-@pytest.fixture()
+@pytest.fixture
 def math_addr(math_contract_factory, address_conversion_func):
     w3 = math_contract_factory.w3
     deploy_txn = math_contract_factory.constructor().transact(

tests/core/contracts/test_extracting_event_data.py

@@ -28,7 +28,7 @@
 )
 
 
-@pytest.fixture()
+@pytest.fixture
 def dup_txn_receipt(w3, indexed_event_contract, wait_for_transaction, event_contract):
     emitter_fn = indexed_event_contract.functions.logTwoEvents
 

tests/core/contracts/test_extracting_event_data_old.py

@@ -9,6 +9,28 @@
 )
 
 
+@pytest.fixture
+def emitter(
+    w3,
+    emitter_contract_data,
+    wait_for_transaction,
+    wait_for_block,
+    address_conversion_func,
+):
+    emitter_contract_factory = w3.eth.contract(**emitter_contract_data)
+
+    wait_for_block(w3)
+    deploy_txn_hash = emitter_contract_factory.constructor().transact({"gas": 10000000})
+    deploy_receipt = wait_for_transaction(w3, deploy_txn_hash)
+    contract_address = address_conversion_func(deploy_receipt["contractAddress"])
+
+    bytecode = w3.eth.get_code(contract_address)
+    assert bytecode == emitter_contract_factory.bytecode_runtime
+    _emitter = emitter_contract_factory(address=contract_address)
+    assert _emitter.address == contract_address
+    return _emitter
+
+
 @pytest.mark.parametrize(
     "contract_fn,event_name,call_args,expected_args",
     (