e2e

A procedure for running and diagnosing end-to-end tests, which test a complete user flow through an application. It classifies failures as flaky, outdated, bugs, or failures that cannot yet be verified against a specification.

In plain words
What is it for?
Investigating intermittent test failures, updating tests whose expected behavior changed, verifying implementation bugs against a specification, and improving waits and selectors.
Why use it?
It prevents developers from masking test problems with arbitrary delays or retries. It connects each type of failure to an appropriate investigation or fix.

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/alleneubank/claude-code/e2e
Any agent
npx skills add alleneubank/claude-code --skill e2e
Clone the repo
git clone --depth 1 https://github.com/alleneubank/claude-code

Made for: Claude Code, Codex.

Per session 42 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 910 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 $0.00042 $0.00910
Opus 5 $0.00021 $0.00455
Sonnet 5 $0.00008 $0.00182
Haiku 4.5 $0.00004 $0.00091

Measured 2d ago against content hash be85925d2f68, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

e2e 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

1 near-identical copy found in the catalogue:

  • e2e — 100% identical, 0 lines differ
.claude/skills/e2e/SKILL.md · 106 lines

How it starts

The opening of the file, as written. The whole thing — 106 lines — stays where its author put it; the contents beside it link to each section on GitHub.

E2E Testing

Failure Taxonomy

Every e2e failure is exactly one of:

A. Flaky (test infrastructure issue)

  • Race conditions, timing-dependent assertions, stale selectors, missing waits
  • Symptom: passes on retry, fails intermittently

B. Outdated (test no longer matches implementation)

  • Test asserts old behavior that was intentionally changed; selectors reference removed elements
  • Symptom: consistent failure, app works correctly

C. Bug (implementation doesn't match spec)

  • Test correctly asserts spec'd behavior, code is wrong
  • Only classify as bug when a spec exists to validate against
  • If no spec exists, classify as "unverified failure" and report to the user

Fix Rules by Category

Flaky fixes:

  • Replace waitForTimeout with auto-waiting locators
  • Replace brittle CSS selectors with getByRole/getByLabel/getByTestId
  • Fix race conditions with expect() web-first assertions
  • Fix mock/route setup ordering (before navigation)
  • Never add arbitrary delays - fix the underlying wait
  • Never add retry loops around assertions - use the framework's built-in retry

Outdated fixes:

  • Update test assertions to match current (correct) behavior
  • Update selectors to match current DOM/API
  • Never change source code - the implementation is correct, the test is stale

Bug fixes:

  • Quote the spec section that defines expected behavior
  • Fix the source code to match the spec
  • Unit tests MUST exist before the fix is complete — write them first if missing (TDD)
  • Never change e2e assertions to match buggy code
  • Never change API contracts or interfaces without spec backing
  • If no spec exists, ask the user: bug or outdated test?

Source Code Boundary

E2e test fixes must not change application logic, API contracts, database schemas, or configuration defaults. The only exception: bug fixes where a spec explicitly defines the correct behavior and unit tests cover the fix.

Workflow

Step 1: Discover Test Infrastructure

Read the full file on GitHub · 106 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 · 106 lines · 42 tokens per session scan A be85925d2f68

Subscribe to this mod's changes

e2e is a skill published in the GitHub repository alleneubank/claude-code (52 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 42 tokens to every session and 910 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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