fake-driven-testing

Installation
SKILL.md

Fake-Driven Testing Architecture for Python

Use this skill when: Writing tests, fixing bugs, adding features, or modifying gateway layers in Python projects.

No prerequisites. This skill is self-contained. It focuses on testing architecture, not language-specific style.

Overview

This skill provides a defense-in-depth testing strategy with five layers for Python applications:

┌─────────────────────────────────────────────────┐
│  Layer 5 "smoke": Business Logic Integration Tests (5%)  │  ← Smoke tests over real system
├─────────────────────────────────────────────────┤
│  Layer 4 "logic": Business Logic Tests (70%)             │  ← Tests over fakes (MOST TESTS)
├─────────────────────────────────────────────────┤
│  Layer 3 "pure": Pure Unit Tests (10%)                   │  ← Zero dependencies, isolated testing
├─────────────────────────────────────────────────┤
│  Layer 2 "real-sanity": Integration Sanity Tests (10%)   │  ← Fast validation with mocking
Related skills
Installs
70
Repository
dagster-io/erk
GitHub Stars
81
First Seen
Jan 20, 2026