Agent skill · data analytics · jeremylongshore

generating-test-data

Generate realistic test data including edge cases and boundary conditions.

Why this skill is useful

Generates edge case test data and factory functions that the AI wouldn't reliably create on its own.

What it needs

Requires factory-boy, faker.js, pytest installed locally. About 3k tokens when loaded. Last updated 2026-08-07. 2,604 stars on the source repository.

What this skill does

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. …

How to use it

Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:

@skills jeremylongshore/generating-test-data--4e96a5

View the source on GitHub

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