Python Mock Isolation Design
Use Python mocks and fakes as a design tool without losing behavioral confidence. Use when testing external dependencies, choosing monkeypatch versus unittest.mock.patch, isolating slow boundaries, avoiding mock-heavy tests, interpreting mock call assertions, or refactoring toward clearer dependency seams.
Testingv0.1.0MITpythontddtestingmockingarchitecture
Install
npx skills add LVTD-LLC/skills --skill python-mock-isolation-designFrom `SKILL.md`
Use this skill when replacing a dependency in a Python test changes what the test proves. Mocks are useful at slow, nondeterministic, or external boundaries; they become harmful when they replace the behavior the test is supposed to validate.