Compatible with Cursor, Claude Code, Cline, Roo Code, Antigravity, GitHub Copilot

Comprehensive Unit Test Suite Generation (AAA Pattern)

Generate mutation-tested unit tests with Arrange-Act-Assert structure, boundary cases, and proper mock boundaries.

TestingJUnitVitestPytestJestTDD

v1.2.0 · Updated 2026-08

Skill Objective

Generate comprehensive unit test suites covering 100% of branches, boundary conditions, malicious inputs, and custom exception handling.

Execution Workflow Procedure

Ordered steps the coding agent executes when performing this skill.

Analyze Function Invariants & Boundaries

Inspect the source code to map all conditional branches, boundary thresholds (0, negative, max values), and exception triggers.

Structure Tests with AAA Pattern

Write individual, single-behavior tests structured clearly into Arrange, Act, and Assert phases with descriptive naming.

Mock Only at System Boundaries

Mock external I/O (network, database, clock) while testing pure domain logic and value objects with real instances.

Agent Safety Guardrails & Anti-Hallucination Rules

DO NOT over-mock internal data structures or helper functions; test public interfaces.
DO NOT write tests that assert multiple unrelated behaviors in a single test case.

Expected Output Format

Runnable test file with 100% branch and edge case coverage.

🧪 Complete Test File: Fully typed, runnable test suite.

📋 Edge Case Matrix: Summary of boundary values tested.

Domain Verification Checks

Boundary Threshold Coverage: Tests exact cutoff numbers (e.g. 99.99 vs 100.00).

Exception Verification: Verifies custom error classes and exact messages.

Parameterized Matrices: Uses table-driven tests for large input permutations.

Example Agent Invocations

"Generate a comprehensive Vitest unit test suite for this pricing calculator class."

"Write JUnit 5 unit tests covering all edge cases and exceptions for this user registration service."

Install / Configure This Skill

# Place in .cursorrules or create .cursor/rules/comprehensive-unit-test-generation.mdc
# Trigger: Whenever you perform comprehensive unit test suite generation (aaa pattern)

---
name: comprehensive-unit-test-generation
description: Generate complete unit test suites adhering to Arrange-Act-Assert with boundary conditions and mock isolation.
version: 1.2.0
compatibility: [Cursor, Claude Code, Cline, Roo Code, Antigravity]
---

# Comprehensive Unit Test Suite Generation (AAA Pattern)

## Objective
Produce reliable, mutation-tested unit test suites with clear Arrange-Act-Assert separation and comprehensive edge case matrices.

## Workflow
1. **Branch & Boundary Mapping**: Identify all decision paths, boundary thresholds, and exception conditions.
2. **AAA Formatting**: Structure tests with clear Arrange, Act, Assert sections and readable test names.
3. **Mock Isolation**: Mock only external I/O boundaries while testing domain logic directly.

Complementary Agent Prompt

Need a quick one-time prompt for chat?

Try the Unit Test Suite Generator with Edge Cases — a lightweight version designed for 1-click copying directly into Claude, ChatGPT, or Cursor chat.

View Prompt