generating-test-data

name	generating-test-data
description	Generate realistic test data including edge cases and boundary conditions. Use when creating realistic fixtures or edge case test data. Trigger with phrases like "generate test data", "create fixtures", or "setup test database".
allowed-tools	Read, Write, Edit, Grep, Glob, Bash(test:data-*)
version	1.24.0
author	Jeremy Longshore <[e-mail]>
license	MIT
tags	["testing","database","test-data"]
compatibility	Designed for Claude Code, also compatible with Codex and OpenClaw

Test Data Generator

Overview

Generate realistic, type-safe test data including fixtures, factory functions, seed datasets, and edge case values. Supports Faker.js, Factory Bot patterns, Fishery (TypeScript factories), pytest fixtures, and database seed scripts.

Prerequisites

• Data generation library installed (Faker.js/@faker-js/faker, Fishery, factory-boy for Python, or JavaFaker)
• Database schema or TypeScript/Python type definitions for the data models
• Test framework with fixture support (Jest, pytest, JUnit)
• Seed management for reproducible random data (faker.seed())
• Database client for seed data insertion (if generating database fixtures)

Instructions

1. Read the project's data models, TypeScript interfaces, database schemas, or ORM definitions to understand the shape of all entities.
2. For each entity, create a factory function that produces a valid default instance:
   • Use Faker methods matched to field semantics (e.g., faker.person.fullName() for names, faker.internet.email() for emails).
   • Provide sensible defaults for required fields.
   • Allow overrides via a partial parameter for test-specific customization.
   • Set a deterministic seed for reproducibility (faker.seed(12345)).
3. Generate edge case data variants for each entity:
   • Empty values: Empty strings, null, undefined, empty arrays.
   • Boundary values: Maximum string length, integer overflow, zero, negative numbers.
   • Unicode and i18n: Names with accents, CJK characters, RTL text, emoji.
   • Adversarial inputs: SQL injection strings, XSS payloads, excessively long strings.
   • Temporal edge cases: Leap years, timezone boundaries, epoch zero, far-future dates.
4. Create relationship factories that build connected entity graphs:
   • A user factory that also creates associated addresses and orders.
   • Configurable depth to avoid infinite recursion.
   • Lazy evaluation for optional relationships.
5. Generate database seed files for integration tests:
   • SQL insert scripts or ORM seed functions.
   • Idempotent operations (use ON CONFLICT or INSERT IF NOT EXISTS).
   • Separate seed sets for different test scenarios (empty state, populated state, edge cases).
6. Write fixture files in JSON, YAML, or TypeScript for static test data: