flake8-mock-spec

1.4.0 verified Sat May 09 auth: no python

A flake8 plugin that ensures mocks are constructed with the `spec` argument, preventing fragile tests. Version 1.4.0 supports Python 3.8+ and requires flake8. It has a release cadence of roughly once a year.

pip install flake8-mock-spec

Common errors

error W8001 mock with no spec ↓

cause The plugin flags any call to Mock(), MagicMock(), or NonCallableMock() without the spec argument.

fix

Add spec=YourClass to the mock constructor, e.g., Mock(spec=MyClass).

Warnings

gotcha The plugin only flags mock.Mock, mock.MagicMock, and mock.NonCallableMock calls without a spec argument. It does not check patched objects (e.g., patch('module.ClassName')) or other mock library variants. ↓

fix Ensure you also manually check patches; use spec parameter in patch calls where appropriate.

deprecated As of version 1.4.0, the plugin is compatible with Python 3.8+ and flake8 4+; older Python versions (3.6, 3.7) are not supported. ↓

fix Upgrade to the latest version and ensure Python >=3.8.1.

Imports

flake8_mock_spec
```
from flake8_mock_spec import *
```
Plugin is auto-loaded by flake8; no manual import needed

Quickstart

Run flake8 after installing the plugin to catch missing spec arguments in mock constructors.

# Install the plugin
# pip install flake8-mock-spec
# Then run flake8 on your code:
# flake8 myproject/

# Example of a lint violation (W8001):
mock = Mock()  # W8001: mock with no spec

# Correct way:
mock = Mock(spec=SomeClass)