import unittest

from itemloaders import ItemLoader
from itemloaders.processors import Identity, Compose, TakeFirst


class TestOutputProcessorDict(unittest.TestCase):
    def test_output_processor(self):

        class TempDict(dict):
            def __init__(self, *args, **kwargs):
                super(TempDict, self).__init__(self, *args, **kwargs)
                self.setdefault('temp', 0.3)

        class TempLoader(ItemLoader):
            default_item_class = TempDict
            default_input_processor = Identity()
            default_output_processor = Compose(TakeFirst())

        loader = TempLoader()
        item = loader.load_item()
        self.assertIsInstance(item, TempDict)
        self.assertEqual(dict(item), {'temp': 0.3})


class TestOutputProcessorItem(unittest.TestCase):
    def test_output_processor(self):
        class TempLoader(ItemLoader):
            default_input_processor = Identity()
            default_output_processor = Compose(TakeFirst())

        item = dict()
        item.setdefault('temp', 0.3)
        loader = TempLoader(item=item)
        item = loader.load_item()
        self.assertIsInstance(item, dict)
        self.assertEqual(dict(item), {'temp': 0.3})