acceptance-test-authoring

A guide to writing acceptance tests: tests that check whether an application behaves as users and stakeholders expect. It covers Cucumber.js for JavaScript and Behave for Python, plus Gherkin, a plain-text format using Given, When, and Then steps.

In plain words
What is it for?
Use it to create or change acceptance tests, configure Cucumber.js or Behave, write step definitions, check Gherkin specifications, choose a testing setup, or handle OpenSpec tasks involving acceptance tests.
Why use it?
It helps keep acceptance-test files, test steps, runners, and project configuration consistent instead of making you work out the testing setup each time.

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/intent-driven-dev/intent-driven-template/acceptance-test-authoring
Any agent
npx skills add intent-driven-dev/intent-driven-template --skill acceptance-test-authoring
Clone the repo
git clone --depth 1 https://github.com/intent-driven-dev/intent-driven-template

Made for: Claude Code, Codex.

Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,793 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 $0.00051 $0.01793
Opus 5 $0.00026 $0.00897
Sonnet 5 $0.00010 $0.00359
Haiku 4.5 $0.00005 $0.00179

Measured yesterday against content hash bd2706d34c7e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

acceptance-test-authoring 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 yesterday.

The scan reads SKILL.md. This mod also ships 7 executable files (references/javascript/cucumber.cjs, references/javascript/extract-gherkin.cjs, references/javascript/openspec-effective-paths.cjs, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

.agents/skills/acceptance-test-authoring/SKILL.md · 121 lines

How it starts

The opening of the file, as written. The whole thing — 121 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Acceptance Test Authoring

When spec-as-source is active, the acceptance suite executes the Gherkin specs that live under openspec/ against the running application. Specs are Markdown files named spec.md: Markdown headings carry the capability, requirement, and scenario structure, while column-0 gherkin fences contain only Given/When/Then steps. The runner extracts them into real .feature files on every run, synthesizing Feature:/Rule:/Scenario: from the headings.

This format is opt-in. Loading this skill without spec-as-source does not override the configured OpenSpec schema templates.

Everything in this file is stack-agnostic. Tool-specific filenames, dependencies, commands, and examples live in the stack packs.

Choosing The Stack

The project's acceptance stack is declared as stack: in openspec/config.yaml:

schema: intent-driven
stack: javascript      # javascript | python

Resolve it in this order:

  1. Use stack: in openspec/config.yaml.
  2. If absent and acceptance-tests/ already exists, infer it from contents: cucumber.cjs means javascript, behave.ini means python; offer to record it.
  3. Otherwise ask. Never guess silently, and never scaffold a runner without a recorded value.

When spec-as-source is active, adding stack: is a specs-zone edit under openspec/; follow that skill's mandatory BDD zone rules before editing it.

Reference Files

Stack Pack Runner
javascript references/javascript/SETUP.md cucumber-js
python references/python/SETUP.md behave 1.2.7+

Each pack has a Files to copy table naming every destination filename and why it is load-bearing. Copy those files verbatim; they are the canonical runner.

Three files sit at the references/ root because they are shared by both stacks:

File Role
EXTRACTION.md Normative contract for spec.md to .feature extraction
COMPOSITION.md Normative contract for which scenarios run
gherkin-lintrc.json Shared lint configuration copied to acceptance-tests/.gherkin-lintrc

Read the full file on GitHub · 121 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. yesterday First seen · 121 lines · 51 tokens per session scan A bd2706d34c7e

Subscribe to this mod's changes

acceptance-test-authoring is a skill published in the GitHub repository intent-driven-dev/intent-driven-template (121 stars, last pushed 8d ago), licensed MIT. It adds 51 tokens to every session and 1,793 once invoked, about $0.0003 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.