Test Data Generator

A skill for creating structured test data for automated software tests. It produces positive, negative, boundary, and unusual edge-case examples that can be used in forms, API requests, searches, and file uploads.

In plain words
What is it for?
Creating registration and login data, form submissions, API payloads, search queries, file-upload inputs, boundary cases, and data-driven test fixtures.
Why use it?
It avoids hand-writing repetitive test values and reduces failures caused by duplicate or hard-to-trace data. Generated values can be unique, repeatable from a seed, and linked to the test that created them.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/anhtester/antigravity-testing-kit/test_data_generator
Any agent
npx skills add anhtester/antigravity-testing-kit --skill test_data_generator
Clone the repo
git clone --depth 1 https://github.com/anhtester/antigravity-testing-kit

Made for: Claude Code, Codex.

Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,511 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00032 $0.01511
Opus 5 $0.00016 $0.00756
Sonnet 5 $0.00006 $0.00302
Haiku 4.5 $0.00003 $0.00151

Measured 2d ago against content hash 940829dc7c9d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

Test Data Generator scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

2 near-identical copies found in the catalogue:

.agent/skills/test_data_generator/SKILL.md · 249 lines

How it starts

The opening of the file, as written. The whole thing — 249 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Test Data Generator

Purpose: Generate reliable test data for automation tests.


When to Use

Use this skill when:

  • Creating test data for new test cases
  • Generating boundary and edge case data
  • Setting up data-driven tests
  • Creating API request payloads

Responsibilities

Generate test data for:

  • Registration forms
  • Login credentials
  • Form submissions
  • API payloads
  • Search queries
  • File uploads

Data Rules

All generated data must be:

  • Unique — No duplication within test suite
  • Deterministic — Same seed produces same data (when needed)
  • Traceable — Can identify which test generated it

Unique Data Pattern

Recommended format:

<prefix>_<testName>_<timestamp>

Examples:

auto_register_20260402133000
test_login_1712024100

Common Data Types

Email

auto_<testName>_<timestamp>@test.com

Example: [email protected]

Username

user_<testName>_<timestamp>

Example: user_login_20260402133000

Phone

Random 10-digit number starting with valid prefix

Example: 0912345678

Password

Mix of uppercase, lowercase, digits, special chars

Example: Test@12345


Data Categories

Positive Data (Happy Path)

  • Valid format, within constraints
  • All required fields filled
  • Standard business values

Negative Data

  • Missing required fields
  • Invalid format (wrong email, short password)
  • Invalid characters
  • Already existing values (duplicate check)

Boundary Values

  • Minimum length (e.g., 1 character)
  • Maximum length (e.g., 255 characters)
  • Min + 1, Max - 1
  • Empty string vs null
  • Zero, negative numbers

Edge Cases

  • Unicode / special characters
  • Very long strings
  • SQL injection patterns (for security testing)
  • HTML tags in text fields
  • Leading/trailing whitespace

Constraints

Test data must:

  • Respect field validation rules (from DOM inspection)
  • Match input format (date format, phone format)
  • Avoid duplication across test runs
  • Not contain real PII (personal data)

Read the full file on GitHub · 249 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 249 lines · 32 tokens per session scan A 940829dc7c9d

Subscribe to this mod's changes

Test Data Generator is a skill published in the GitHub repository anhtester/antigravity-testing-kit (131 stars, last pushed 1mo ago), licensed MIT. It adds 32 tokens to every session and 1,511 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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