evidence-validate

name	evidence-validate
description	Playwright-based evidence capture protocol. Produces screenshot + HTML + console proof mapped per AC ID. Used by kopi-validate agent to generate pass/fail evidence for the evidence-manifest.
license	MIT
allowed-tools	["mcp__playwright__browser_navigate","mcp__playwright__browser_click","mcp__playwright__browser_take_screenshot","mcp__playwright__browser_snapshot","mcp__playwright__browser_evaluate","mcp__playwright__browser_wait_for"]

evidence-validate

Playwright-based evidence capture protocol. Produces screenshot + HTML + console proof mapped per AC ID.

Protocol

Setup

const browser = await chromium.launch();
const context = await browser.newContext();
const page = await context.newPage();
page.on('console', msg => log(msg));
page.on('pageerror', err => log(err));

Per AC: Evidence Capture Sequence

1. Navigate to the relevant page/state
2. SCREENSHOT: before state (before.png)
3. Execute the Given/When action
4. SCREENSHOT: after state (after.png)
5. CAPTURE: page.content() → save as .html
6. CAPTURE: console log buffer → save as .txt
7. Assert the Then condition
8. Record: pass | fail | skip | blocked

Screenshot Naming

evidence/AC-{taskId}-{acSeq}-before.png
evidence/AC-{taskId}-{acSeq}-after.png

Assertion Patterns

AC category	Playwright assertion
behavior	await expect(locator).toHaveState(...)
display	await expect(locator).toBeVisible()
validation	await expect(locator).toHaveText(/error/)
navigation	await expect(page).toHaveURL(...)
accessibility	await checkA11y(page, null, {...})

Blocked Classification

Mark as blocked (not fail) when test environment is unavailable, required test data doesn't exist, or upstream dependency is not deployed. Always explain in notes.

Output Format

Output feeds artifacts/active/evidence-manifest-{taskId}.json and must conform to contracts/evidence-manifest.schema.json. Required top-level fields are artifact_type, artifact_version, task_id, trace_id, results, summary, generated_at, generated_by, and generated_by_model.

{
  "ac_id": "AC-kopi-42-001",
  "status": "pass",
  "screenshot_before": "evidence/AC-kopi-42-001-before.png",
  "screenshot_after": "evidence/AC-kopi-42-001-after.png",
  "html_path": "evidence/AC-kopi-42-001.html",
  "console_path": "evidence/AC-kopi-42-001-console.txt",
  "assertion": "Login button disabled when form is empty",
  "notes": ""
}

Pass Rate

pass_rate = pass_count / (pass + fail + skip + blocked)

DoD requires pass_rate >= 0.8.