Improve error handling of account init with invalid key (#158)

* add try/except for signer

* fix msg

* fix test

src/nile/core/account.py

@@ -1,4 +1,5 @@
 """Command to call or invoke StarkNet smart contracts."""
+import logging
 import os
 
 from dotenv import load_dotenv
@@ -20,8 +21,16 @@ class Account:
 
     def __init__(self, signer, network):
         """Get or deploy an Account contract for the given private key."""
-        self.signer = Signer(int(os.environ[signer]))
-        self.network = network
+        try:
+            self.signer = Signer(int(os.environ[signer]))
+            self.network = network
+        except KeyError:
+            logging.error(
+                f"\n❌ Cannot find {signer} in env."
+                "\nCheck spelling and that it exists."
+                "\nTry moving the .env to the root of your project."
+            )
+            return
 
         if accounts.exists(str(self.signer.public_key), network):
             signer_data = next(accounts.load(str(self.signer.public_key), network))

tests/commands/test_account.py

@@ -1,4 +1,5 @@
 """Tests for account commands."""
+import logging
 from unittest.mock import MagicMock, patch
 
 import pytest
@@ -27,6 +28,17 @@ def test_account_init(mock_deploy):
     mock_deploy.assert_called_once()
 
 
+def test_account_init_bad_key(caplog):
+    logging.getLogger().setLevel(logging.INFO)
+
+    Account("BAD_KEY", NETWORK)
+    assert (
+        "\n❌ Cannot find BAD_KEY in env."
+        "\nCheck spelling and that it exists."
+        "\nTry moving the .env to the root of your project."
+    ) in caplog.text
+
+
 def test_account_multiple_inits_with_same_key():
     account = Account(KEY, NETWORK)
     account.deploy()