data-strategy

A set of rules for organizing test data in a Playwright project. It uses generated data for normal test cases and fixed TypeScript values for carefully selected invalid or domain-specific cases.

In plain words
What is it for?
Use it when creating data factories, fixed invalid-value lists, or curated test cases for names, emails, products, descriptions, and other application data.
Why use it?
It prevents tests from sharing accidental data, becoming unpredictable, or scattering repeated values across test files. It also keeps invalid-input cases consistent and validates generated data before use.

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/idavidov13/agentic-playwright/data-strategy
Any agent
npx skills add idavidov13/agentic-playwright --skill data-strategy
Clone the repo
git clone --depth 1 https://github.com/idavidov13/agentic-playwright

Made for: Claude Code, Codex.

Per session 160 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,957 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 $0.00160 $0.02957
Opus 5 $0.00080 $0.01478
Sonnet 5 $0.00032 $0.00591
Haiku 4.5 $0.00016 $0.00296

Measured 3d ago against content hash 61a821dad24c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

data-strategy 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 3d 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.

.claude/skills/data-strategy/SKILL.md · 236 lines

How it starts

The opening of the file, as written. The whole thing — 236 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Data Strategy

This framework uses a bifurcated data strategy: static data for deterministic curated cases and dynamic factories for test isolation.

Critical

  • Static data files are TypeScript only. Every file under test-data/static/** is a .ts file that exports as const literal values. NEVER use .json.
  • Static data files may only export literal values. No runtime imports (type-only imports are fine), no function definitions, no computed values, no Faker calls. Dynamic data belongs in factories, not in static files.
  • NEVER hardcode test content strings (names, emails, todo text, product names, descriptions, etc.) in a spec file. Generate with a Faker factory.
  • NEVER redefine universal type-mismatch arrays ([123, true, null, undefined], etc.) inline. Import them from test-data/static/util/invalid-values.ts.
  • ALWAYS validate factory output with Schema.parse(...) and return the Zod-inferred type.
  • NEVER generate app-defined strings with Faker (error messages, button labels, page headers). Those live in enums/ so they stay in sync with the application under test.
  • NEVER store fixed expected values that are used in a single assertion in a static data file. Keep them inline in the test.
  • ALWAYS follow the refactor-values skill before editing any existing static-data file or enum value — these edits cascade through assertions and data-driven loops.
  • NEVER introduce magic numbers (timeouts, retry counts, limits) inline. Prefer web-first assertions; when a numeric value is unavoidable, route it through playwright.config.ts or an enum in enums/.

File Locations

{area} is a placeholder. Before creating or referencing any path below, run ls test-data/static/ and ls test-data/factories/ to discover the real subdirectory names in this repo (e.g., front-office, back-office) and use those instead.

Type Directory Purpose
Universal invalid arrays test-data/static/util/ Type-mismatch tuples reused by every negative test (.ts, as const)
Domain-specific static test-data/static/{area}/ Curated invalid/boundary sets tied to the app's validation rules (.ts, as const)
Dynamic factories test-data/factories/{area}/ Faker + Zod factories for unique, valid data per test run

Read the full file on GitHub · 236 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 3d ago First seen · 236 lines · 160 tokens per session scan A 61a821dad24c

Subscribe to this mod's changes

data-strategy is a skill published in the GitHub repository idavidov13/agentic-playwright (139 stars, last pushed 6d ago), licensed MIT. It adds 160 tokens to every session and 2,957 once invoked, about $0.0008 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.