Smart object for mocking open file calls, depends on file path
Project Description
Description
This library contains object, which can be used during mocking files in tests. Features:
- You can register different actions (provide different objects) for different paths
- You can add text, which will be returned on read
- You can select behavior for paths, which are not registered.
Supported behaviors:
- Raise FileNotFoundError exception (default behavior)
- Return original file from filesystem
- Return mock object
Install
It can be installed with following command:
pip install open-mock-file
Usage:
Examples
Mock open first file with custom object, second one with string data and raise FileNotFoundError for not registered path:
from unittest.mock import patch from open_file_mock import MockOpen class FileObject: def __init__(self, data): self.data = data def read(self, *args, **kwargs): return self.data def write(self, data, *args, **kwargs): self.data = data def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): pass with patch('builtins.open', new_callable=MockOpen) as open_mock: open_mock.register_object_for_path(path='/tmp/f1', obj=FileObject('Some data')) open_mock.set_read_data_for(path='/tmp/f2', data='file2 data') with open('/tmp/f1') as f1: print(f1.read()) f1.write('Other data') print(f1.read()) print('----------------------') with open('/tmp/f2') as f2: print(f2.read()) print('----------------------') open('/etc/hostname')
output:
Some data Other data ---------------------- file2 data ---------------------- Traceback (most recent call last): ... FileNotFoundError: File /etc/hostname not found in mock function
Set default behavior (for not registered paths) to return original file:
from unittest.mock import patch, MagicMock from open_file_mock import MockOpen, DEFAULTS_ORIGINAL with patch('builtins.open', new_callable=MockOpen) as open_mock: open_mock.default_behavior = DEFAULTS_ORIGINAL open_mock.register_object_for_path(path='/tmp/f1', obj=MagicMock()) with open('/tmp/f1') as f1: print(f1.read()) print('----------------------') with open('/etc/hostname') as f2: print(f2.read()) print('----------------------')
output:
<MagicMock name='mock.__enter__().read()' id='...'> ---------------------- myhost ----------------------
Set default behavior to return new mock:
from unittest.mock import patch from open_file_mock import MockOpen, DEFAULTS_MOCK with patch('builtins.open', new_callable=MockOpen) as open_mock: open_mock.default_behavior = DEFAULTS_MOCK open_mock.set_read_data_for('/tmp/f1', 'QWERTY') with open('/tmp/f1') as f1: print(f1.read()) print('----------------------') with open('/etc/hostname') as f2: print(f2.read()) print('----------------------')
output:
QWERTY ---------------------- <MagicMock name='mock.__enter__().read()' id='...'> ----------------------
Yoy can get registered object with get_object_for_path method:
from unittest.mock import patch from open_file_mock import MockOpen class FileObject: def __init__(self, data): self.data = data def read(self, *args, **kwargs): return self.data def write(self, data, *args, **kwargs): self.data = data def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): pass with patch('builtins.open', new_callable=MockOpen) as open_mock: open_mock.register_object_for_path(path='/tmp/f1', obj=FileObject('Some data')) open_mock.set_read_data_for(path='/tmp/f2', data='file2 data') with open('/tmp/f1') as f1: print(f1.read()) print('----------------------') print(open_mock.get_object_for_path('/tmp/f1'))
output:
Some data ---------------------- <__main__.FileObject object at ...>
Object methods:
- register_object_for_path(path, obj) - allow to register new object for provided path. Can be used once for particular path
- update_object_for_path(path, obj) - update registered path or create new mapping if not exists
- unregister_path(path) - remove path mapping
- set_read_data_for(path, data) - set data which will be returned of file read
- get_object_for_path(path) - returns object registered for path. If mapping not exists, raises KeyError
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Filename, size & hash SHA256 hash help | File type | Python version | Upload date |
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open_mock_file-1.0.2-py3-none-any.whl (7.7 kB) Copy SHA256 hash SHA256 | Wheel | py3 | Jan 28, 2018 |