Fix network handling

src/nile/common.py

@@ -38,15 +38,20 @@ def get_gateways():
     """Get the StarkNet node details."""
     try:
         with open(NODE_FILENAME, "r") as f:
-            gateway = json.load(f)
-            return gateway
+            gateways = json.load(f)
+            return gateways
 
     except FileNotFoundError:
-        with open(NODE_FILENAME, "w") as f:
-            gateways = {"localhost": "http://127.0.0.1:5050/", **DEFAULT_GATEWAYS}
-            f.write(json.dumps(gateways, indent=2))
+        gateways = create_node_json()
+        return gateways
 
-            return gateways
+
+def create_node_json(network="localhost", gateway_url="http://127.0.0.1:5050/"):
+    """Create node.json and return gateways."""
+    with open(NODE_FILENAME, "w") as f:
+        gateways = {network: gateway_url, **DEFAULT_GATEWAYS}
+        f.write(json.dumps(gateways, indent=2))
+        return gateways
 
 
 GATEWAYS = get_gateways()

src/nile/core/node.py

@@ -1,25 +1,20 @@
 """Command to start StarkNet local network."""
-import json
 import logging
 import subprocess
 
-from nile.common import NODE_FILENAME, DEFAULT_GATEWAYS
+from nile.common import create_node_json
 
 
 def node(host="127.0.0.1", port=5050, seed=None, lite_mode=False):
     """Start StarkNet local network."""
     try:
         # Save host and port information to be used by other commands
-        file = NODE_FILENAME
         if host == "127.0.0.1":
             network = "localhost"
         else:
             network = host
         gateway_url = f"http://{host}:{port}/"
-        gateways = {network: gateway_url, **DEFAULT_GATEWAYS}
-
-        with open(file, "w+") as f:
-            json.dump(gateways, f, indent=2)
+        create_node_json(network, gateway_url)
 
         command = ["starknet-devnet", "--host", host, "--port", str(port)]
 

tests/test_common.py

@@ -1,8 +1,13 @@
 """Tests for common library."""
+import json
+from unittest.mock import mock_open, patch
+
 import pytest
 
 from nile.common import (
     DEFAULT_GATEWAYS,
+    NODE_FILENAME,
+    create_node_json,
     get_gateways,
     parse_information,
     prepare_params,
@@ -16,6 +21,7 @@
 LIST3 = [1, 2, 3, [4, 5, 6, [7, 8, 9]]]
 STDOUT_1 = "SDTOUT_1"
 STDOUT_2 = "SDTOUT_2"
+LOCAL_GATEWAY = {"localhost": "http://127.0.0.1:5050/"}
 
 
 @pytest.mark.parametrize(
@@ -58,6 +64,23 @@ def test_parse_information():
 
 def test_get_gateways():
     gateways = get_gateways()
-    expected = {"localhost": "http://127.0.0.1:5050/", **DEFAULT_GATEWAYS}
+    expected = {**LOCAL_GATEWAY, **DEFAULT_GATEWAYS}
 
     assert gateways == expected
+
+
+@pytest.mark.parametrize(
+    "args, gateway", [(None, LOCAL_GATEWAY), (["a", "b"], {"a": "b"})]
+)
+def test_create_node_json(args, gateway):
+    open_mock = mock_open()
+    with patch("nile.common.open", open_mock, create=True):
+        if args is None:
+            create_node_json()
+        else:
+            create_node_json(*args)
+
+    expected = json.dumps({**gateway, **DEFAULT_GATEWAYS}, indent=2)
+
+    open_mock.assert_called_with(NODE_FILENAME, "w")
+    open_mock.return_value.write.assert_called_once_with(expected)