Add tests for build_config

freqtrade/commands/build_config_commands.py

@@ -27,6 +27,19 @@ def validate_is_float(val):
         return False
 
 
+def ask_user_overwrite(config_path: Path) -> bool:
+    questions = [
+        {
+            "type": "confirm",
+            "name": "overwrite",
+            "message": f"File {config_path} already exists. Overwrite?",
+            "default": False,
+        },
+    ]
+    answers = prompt(questions)
+    return answers['overwrite']
+
+
 def ask_user_config() -> Dict[str, Any]:
     """
     Ask user a few questions to build the configuration.
@@ -169,6 +182,10 @@ def start_new_config(args: Dict[str, Any]) -> None:
 
     config_path = Path(args['config'][0])
     if config_path.exists():
+        overwrite = ask_user_overwrite(config_path)
+        if overwrite:
+            config_path.unlink()
+        else:
             raise OperationalException(
                 f"Configuration `{config_path}` already exists. "
                 "Please use another configuration name or delete the existing configuration.")

tests/commands/test_build_config.py

@@ -1,8 +1,8 @@
-import json
 from pathlib import Path
 from unittest.mock import MagicMock
 
 import pytest
+import rapidjson
 
 from freqtrade.commands.build_config_commands import (ask_user_config,
                                                       start_new_config)
@@ -13,7 +13,10 @@ from tests.conftest import get_args, log_has_re
 @pytest.mark.parametrize('exchange', ['bittrex', 'binance', 'kraken', 'ftx'])
 def test_start_new_config(mocker, caplog, exchange):
     wt_mock = mocker.patch.object(Path, "write_text", MagicMock())
-    mocker.patch.object(Path, "exists", MagicMock(return_value=False))
+    mocker.patch.object(Path, "exists", MagicMock(return_value=True))
+    unlink_mock = mocker.patch.object(Path, "unlink", MagicMock())
+    mocker.patch('freqtrade.commands.build_config_commands.ask_user_overwrite', return_value=True)
+
     sample_selections = {
         'max_open_trades': 3,
         'stake_currency': 'USDT',
@@ -39,13 +42,16 @@ def test_start_new_config(mocker, caplog, exchange):
 
     assert log_has_re("Writing config to .*", caplog)
     assert wt_mock.call_count == 1
-    result = json.loads(wt_mock.call_args_list[0][0][0])
+    assert unlink_mock.call_count == 1
+    result = rapidjson.loads(wt_mock.call_args_list[0][0][0],
+                             parse_mode=rapidjson.PM_COMMENTS | rapidjson.PM_TRAILING_COMMAS)
     assert result['exchange']['name'] == exchange
     assert result['ticker_interval'] == '15m'
 
 
 def test_start_new_config_exists(mocker, caplog):
     mocker.patch.object(Path, "exists", MagicMock(return_value=True))
+    mocker.patch('freqtrade.commands.build_config_commands.ask_user_overwrite', return_value=False)
     args = [
         "new-config",
         "--config",