def test_from_json(self):
json_obj = [{'source': [1, 2, 3], 'target': [4, 5, 6]},
{'source': [1, 2, 3], 'target': [4, 5, 6]}]
file_path = '/path/to/json_file'
import json # noqa: F401
open_patcher = patch('data.open')
json_load_patcher = patch('json.load', return_value=json_obj)
open_mock = open_patcher.start()
json_load_mock = json_load_patcher.start()
source = Field()
target = Field()
examples = Loader.from_json(file_path, {'source': source, 'target': target})
open_mock.assert_called_once_with(file_path)
json_load_mock.assert_called_once_with(open_mock(file_path).__enter__())
self.assertEqual(len(examples['source']), 2)
self.assertEqual(len(examples['target']), 2)
self.assertListEqual(examples['source'].data, [[1, 2, 3], [1, 2, 3]])
self.assertListEqual(examples['target'].data, [[4, 5, 6], [4, 5, 6]])
open_patcher.stop()
json_load_patcher.stop()
