fix test

monkey patching environment variables failed due to a strange config for sleep times

tests/e2e/test_blockchain_data.py

@@ -1,13 +1,29 @@
-from os import getenv
+from os import getenv, environ
+from unittest.mock import patch
 
 from dotenv import load_dotenv
+import pytest
 from web3 import Web3
-from src.helpers.blockchain_data import BlockchainData
 
 load_dotenv()
 
 
-def tests_get_tx_hashes_blocks():
+@pytest.fixture()
+def set_env_variables(monkeypatch):
+    """Set `REMOVE_SOLVER_PK` to a string so that blacklisting can be called."""
+    with patch.dict(environ, clear=True):
+        envvars = {
+            "CHAIN_SLEEP_TIME": "1",
+        }
+        for k, v in envvars.items():
+            monkeypatch.setenv(k, v)
+        yield  # This is the magical bit which restore the environment after
+
+
+def tests_get_tx_hashes_blocks(set_env_variables):
+    # import has to happen after patching environment variable
+    from src.helpers.blockchain_data import BlockchainData
+
     web3 = Web3(Web3.HTTPProvider(getenv("NODE_URL")))
     blockchain = BlockchainData(web3)
     start_block = 20892118