test_empty_values_autoconfig.py

# coding: utf-8
import os
import sys
from mock import patch, MagicMock
import pytest
from decouple import AutoConfig, UndefinedValueError

# Useful for very coarse version differentiation.
PY3 = sys.version_info[0] == 3

if PY3:
    from io import StringIO
else:
    from io import BytesIO as StringIO


ENVFILE = '''
# Empty values
DB_PORT=
SECRET=
DEBUG=
LIST_VALUES=

# Non-empty values for comparison
DB_HOST=localhost
SECRET_KEY=abc123
'''


def test_autoconfig_empty_value_with_default_int():
    """Test that an empty DB_PORT with default and int cast works correctly with AutoConfig."""
    config = AutoConfig()
    
    # Mock the _find_file method to return a fake path
    fake_path = os.path.join('fake', 'path', '.env')
    config._find_file = MagicMock(return_value=fake_path)
    
    # Mock open to return our test env content
    with patch('decouple.open', return_value=StringIO(ENVFILE), create=True):
        # DB_PORT= (empty) should use the default value 5432
        assert 5432 == config('DB_PORT', default=5432, cast=int)


def test_autoconfig_empty_value_with_default_none():
    """Test that an empty SECRET with default=None works correctly with AutoConfig."""
    config = AutoConfig()
    
    # Mock the _find_file method to return a fake path
    fake_path = os.path.join('fake', 'path', '.env')
    config._find_file = MagicMock(return_value=fake_path)
    
    # Mock open to return our test env content
    with patch('decouple.open', return_value=StringIO(ENVFILE), create=True):
        # SECRET= (empty) should use the default value None
        assert None is config('SECRET', default=None)


def test_autoconfig_empty_value_with_default_bool():
    """Test that an empty DEBUG with default and bool cast works correctly with AutoConfig."""
    config = AutoConfig()
    
    # Mock the _find_file method to return a fake path
    fake_path = os.path.join('fake', 'path', '.env')
    config._find_file = MagicMock(return_value=fake_path)
    
    # Mock open to return our test env content
    with patch('decouple.open', return_value=StringIO(ENVFILE), create=True):
        # DEBUG= (empty) should use the default value True
        assert True is config('DEBUG', default=True, cast=bool)
        # Empty value without default should be False when cast to bool
        assert False is config('DEBUG', cast=bool)


def test_autoconfig_empty_value_with_csv_cast():
    """Test that an empty LIST_VALUES with Csv cast works correctly with AutoConfig."""
    from decouple import Csv
    
    config = AutoConfig()
    
    # Mock the _find_file method to return a fake path
    fake_path = os.path.join('fake', 'path', '.env')
    config._find_file = MagicMock(return_value=fake_path)
    
    # Mock open to return our test env content
    with patch('decouple.open', return_value=StringIO(ENVFILE), create=True):
        # LIST_VALUES= (empty) should return an empty list with Csv cast
        assert [] == config('LIST_VALUES', cast=Csv())
        # With default values
        assert ['default'] == config('LIST_VALUES', default='default', cast=Csv())