Add test for config_utils.file_config()

tests/test_config_utils.py

@@ -1,4 +1,5 @@
 import copy
+from unittest.mock import mock_open, patch
 
 import pytest
 
@@ -9,6 +10,12 @@ from bigchaindb import exceptions
 ORIGINAL_CONFIG = copy.deepcopy(bigchaindb._config)
 
 
+@pytest.fixture
+def ignore_local_config_file(monkeypatch):
+    from bigchaindb.config_utils import file_config
+    monkeypatch.setattr('bigchaindb.config_utils.file_config', file_config)
+
+
 @pytest.fixture(scope='function', autouse=True)
 def clean_config(monkeypatch):
     monkeypatch.setattr('bigchaindb.config', copy.deepcopy(ORIGINAL_CONFIG))
@@ -205,3 +212,11 @@ def test_update_config(monkeypatch):
     assert bigchaindb.config['database']['host'] == 'test-host'
     assert bigchaindb.config['database']['name'] == 'bigchaindb_other'
     assert bigchaindb.config['database']['port'] == 28016
+
+
+def test_file_config():
+    from bigchaindb.config_utils import file_config, CONFIG_DEFAULT_PATH
+    with patch('builtins.open', mock_open(read_data='{}')) as m:
+        config = file_config()
+    m.assert_called_once_with(CONFIG_DEFAULT_PATH)
+    assert config == {}