e2e-testing-patterns

e2e-testing-patterns is a skill for Claude Code from wshobson/agents. It costs 51 tokens per session (994 once invoked), scanned A, original, MIT.

A guide to end-to-end tests, which check complete user journeys through an application, using Playwright and Cypress. It covers workflows such as logging in, checking out, and completing forms.

In plain words
What is it for?
Use it to create browser tests, check critical workflows, investigate flaky tests, test across browsers, and run tests in CI.
Why use it?
It helps catch failures that appear only when several parts of an application work together, including browser and authentication problems.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the developer-essentials plugin — 11 skills, 1 agent shipped together

Good fit Use it to create browser tests, check critical workflows, investigate flaky tests, test across browsers, and run tests in CI.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/wshobson/agents/e2e-testing-patterns
About the project

Agentic Plugin Marketplace is a collection of reusable plugins, agents, skills, commands, and rules for coding-agent tools including Claude Code, Codex CLI, Cursor, OpenCode, Antigravity CLI, and GitHub Copilot. It is for developers assembling agentic workflows across multiple harnesses from shared Markdown sources, and the catalogue entries are examples or subsets of those workflow components.

wshobson/agents · 41,158 stars · on GitHub · sethhobson.com

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.

Any agent
npx skills add wshobson/agents --skill e2e-testing-patterns
Clone the repo
git clone --depth 1 https://github.com/wshobson/agents

Made for: Claude Code.

Or install developer-essentials, the plugin that ships this one along with the rest of its 11 skills, 1 agent.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for e2e-testing-patterns

README.md
[![agentmods](https://agentmods.dev/badge/skills/wshobson/agents/e2e-testing-patterns/github.svg)](https://agentmods.dev/skills/wshobson/agents/e2e-testing-patterns)
Your own site
<a href="https://agentmods.dev/skills/wshobson/agents/e2e-testing-patterns"><img src="https://agentmods.dev/badge/skills/wshobson/agents/e2e-testing-patterns/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for e2e-testing-patterns

Your own site · 80×15
<a href="https://agentmods.dev/skills/wshobson/agents/e2e-testing-patterns"><img src="https://agentmods.dev/badge/skills/wshobson/agents/e2e-testing-patterns.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 994 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • Socket pass 14 Sept 2026
  • Snyk pass 14 Sept 2026
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 2 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium MCP Rug Pull · line 103
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 106
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
How audits are shown
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 5.1 $0.00051 $0.00994
Opus 5.5 $0.00020 $0.00398
Sonnet 5.5 $0.00010 $0.00199
Haiku 4.5 $0.00005 $0.00099

Measured 4d ago against content hash b59a3d80c852, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

e2e-testing-patterns 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 4d 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

8 near-identical copies found in the catalogue:

plugins/developer-essentials/skills/e2e-testing-patterns/SKILL.md · 129 lines

How it starts

The opening of the file, as written. The whole thing — 129 lines — stays where its author put it; the contents beside it link to each section on GitHub.

E2E Testing Patterns

Build reliable, fast, and maintainable end-to-end test suites that provide confidence to ship code quickly and catch regressions before users do.

When to Use This Skill

  • Implementing end-to-end test automation
  • Debugging flaky or unreliable tests
  • Testing critical user workflows
  • Setting up CI/CD test pipelines
  • Testing across multiple browsers
  • Validating accessibility requirements
  • Testing responsive designs
  • Establishing E2E testing standards

Core Concepts

1. E2E Testing Fundamentals

What to Test with E2E:

  • Critical user journeys (login, checkout, signup)
  • Complex interactions (drag-and-drop, multi-step forms)
  • Cross-browser compatibility
  • Real API integration
  • Authentication flows

What NOT to Test with E2E:

  • Unit-level logic (use unit tests)
  • API contracts (use integration tests)
  • Edge cases (too slow)
  • Internal implementation details

2. Test Philosophy

The Testing Pyramid:

        /\
       /E2E\         ← Few, focused on critical paths
      /─────\
     /Integr\        ← More, test component interactions
    /────────\
   /Unit Tests\      ← Many, fast, isolated
  /────────────\

Best Practices:

  • Test user behavior, not implementation
  • Keep tests independent
  • Make tests deterministic
  • Optimize for speed
  • Use data-testid, not CSS selectors

Detailed patterns and worked examples

Detailed pattern documentation lives in references/details.md. Read that file when the navigation tier above is insufficient.

Best Practices

  1. Use Data Attributes: data-testid or data-cy for stable selectors
  2. Avoid Brittle Selectors: Don't rely on CSS classes or DOM structure
  3. Test User Behavior: Click, type, see - not implementation details
  4. Keep Tests Independent: Each test should run in isolation
  5. Clean Up Test Data: Create and destroy test data in each test
  6. Use Page Objects: Encapsulate page logic
  7. Meaningful Assertions: Check actual user-visible behavior
  8. Optimize for Speed: Mock when possible, parallel execution

Read the full file on GitHub · 129 lines

Files

What ships with it

1 file 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. 4d ago Changed · +1 lines b59a3d80c852
  2. 1mo ago First seen · 128 lines · 51 tokens per session scan A 1653690dde9e

Subscribe to this mod's changes

e2e-testing-patterns is a skill published in the GitHub repository wshobson/agents (41,158 stars, last pushed today), licensed MIT. It adds 51 tokens to every session and 994 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-09-03.

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