Cfn E2e

CFN E2E Skill

Purpose

Smart parallel E2E test execution with automatic batching optimization. Reduces test execution time by 2-3x while staying within memory limits.

Core Innovation: Runs fast batches in parallel (2-3 concurrent), large batches sequentially to avoid overwhelming RAM while maximizing throughput.

Leaked workers: If a Playwright/test runner dies and orphans worker processes (reparented to PID 1), .claude/hooks/reap-orphan-test-workers.sh reaps them so they do not burn CPU/RAM.

Inputs

Outputs

• stdout: Test progress and results summary
• exit code: 0 = all passed, 1 = failures, 2 = configuration error
• JSON report: /tmp/cfn-e2e-results-<timestamp>.json

Usage

Basic Usage

# Run all E2E tests with smart batching
$HOME/.claude/skills/cfn-e2e/run-e2e-smart.sh

# Run only smoke tests
BATCH_SIZE=smoke ./.claude/skills/cfn-e2e/run-e2e-smart.sh

# Custom test directory
TEST_DIR=e2e ./.claude/skills/cfn-e2e/run-e2e-smart.sh

# Lower parallelism for 16GB RAM
PARALLELISM=2 WORKERS=2 HEAP_SIZE_MB=4096 ./.claude/skills/cfn-e2e/run-e2e-smart.sh

Analyze Batches Only

# Discover and categorize tests without running
$HOME/.claude/skills/cfn-e2e/analyze-batches.sh tests/e2e

Console / Network Guard (strict mode)

E2E runs pass even when a page logs console.error, throws an uncaught error, or serves a 4xx/5xx: the assertions never look at the console or network. The console-guard fixture closes that gap by failing any test whose page produced a console error, a page error, a same-origin 4xx/5xx response, or a failed request.

Install (copy the fixture into your project)

1. Copy lib/console-guard.ts to your project's tests/e2e/fixtures/console-guard.ts.

2. Swap the import in each spec (the extended test/expect are drop-in):

   // before
   import { test, expect } from '@playwright/test';
   // after
   import { test, expect } from '../fixtures/console-guard';
   

   Adjust the relative path to where the spec lives. Dependency-free beyond @playwright/test.

Opt out (per test)

Some tests exercise the error path on purpose. Annotate those with allow-console-errors and the guard skips its teardown assertions:

test('renders the client-side error banner',
  { annotation: { type: 'allow-console-errors', description: 'asserts the error path' } },
  async ({ page }) => { /* ... */ });

Enforce wiring in CI (--strict-console)

# Fail the run if no spec imports the console-guard fixture.
$HOME/.claude/skills/cfn-e2e/run-e2e-smart.sh --strict-console
# Equivalent via env:
CFN_E2E_STRICT_CONSOLE=1 ./.claude/skills/cfn-e2e/run-e2e-smart.sh

Strict mode greps the spec files and records console_guard in the results JSON: present (every spec imports the fixture), partial (some do), or absent (none). absent exits 1. Strict mode also aggregates any console-violation attachments and screenshots from test-results/** into two new results-JSON arrays: artifacts and failed_files. Non-strict output is unchanged.

WSL2 note

The guard adds zero extra memory: listeners run in-process on the existing page object (no new browser, worker, or process), so it does not affect batch sizing or the WSL2 memory profile.

Batch Heuristics

Configuration

Environment Variables

# Node.js heap size (default: 6GB for 48GB RAM systems)
export NODE_OPTIONS="--max-old-space-size=6144"

# Playwright workers per batch
export PLAYWRIGHT_WORKERS=3

# Test timeout
export PLAYWRIGHT_TIMEOUT=30000

Project Requirements

1. Playwright installed: npx playwright --version
2. Test files pattern: *.spec.ts or *.test.ts
3. playwright.config.ts: Standard Playwright configuration

Memory Profiles

Performance Metrics

Dependencies

• Node.js v18+
• Playwright v1.40+
• Bash 4.0+
• CFN Utilities (optional, for structured logging)

Execution Modes

Task Mode (CFN Loop)

For autonomous E2E execution with iteration on failures:

/cfn-loop-task "Run E2E tests and fix failures" --mode=standard

This triggers the full CFN Loop workflow:

1. Loop 3: Implementation agents run E2E tests
2. Gate Check: Validates pass rate against threshold
3. Loop 2: Validator agents review failures
4. Product Owner: Decides PROCEED/ITERATE/ABORT

Command reference: .claude/commands/cfn-loop-task.md

Error Mode (Fix Failures)

When E2E tests fail and need fixing:

/cfn-fix-errors typescript --max-parallel=5

This triggers the error coordination workflow:

1. Phase 0: Fix root-cause files (type definitions, configs)
2. Phase 1: Parallel fixes for remaining files
3. Phase 2: Cross-file cleanup

Command reference: .claude/commands/cfn-fix-errors.md

Parallel Mode (Pipeline Execution)

Not available. cfn-parallel-execute was documented but never built: no skill of that name exists on disk or in git history. Route "in parallel" and "parallel execution" requests to Task Mode (/cfn-loop-task), which spawns and replaces agents itself, or to Direct Mode below.

Direct Mode (Script Only)

For simple test execution without CFN orchestration:

$HOME/.claude/skills/cfn-e2e/run-e2e-smart.sh

Integration

CFN Loop Integration

# Full autonomous loop with E2E validation
/cfn-loop-task "Run E2E tests" --mode=standard --config='{"batch_size":"smoke"}'

# On failures, trigger error fixing
/cfn-fix-errors typescript

CI/CD Integration

# GitHub Actions example
- name: Run E2E Tests
  run: |
    PARALLELISM=2 WORKERS=2 ./.claude/skills/cfn-e2e/run-e2e-smart.sh
  env:
    NODE_OPTIONS: --max-old-space-size=4096

Files

Known Limitations

1. WSL2 Memory Monitor: Kills processes >10% RAM per process
2. Dev Server Overhead: Each batch may start/stop dev server
3. Test Isolation: No shared state between batches
4. Browser Instances: 2-3 workers × 2-3 batches = 4-9 browsers max

Troubleshooting

Tests killed unexpectedly

• Check WSL memory monitor: ~/.local/bin/wsl-memory-monitor.sh --status
• Reduce WORKERS or PARALLELISM
• Reduce HEAP_SIZE_MB

Tests timing out

• Increase TIMEOUT_MS
• Check if dev server is running
• Verify network connectivity for external APIs

Batch analyzer finds no tests

• Verify TEST_DIR path
• Check file patterns (*.spec.ts, *.test.ts)
• Ensure playwright.config.ts exists

Version History

• 1.1.0 (2026-07-09): Console/network guard fixture (lib/console-guard.ts) + --strict-console wiring gate (W7/G43). Hardened batch arithmetic for set -e.
• 1.0.0 (2025-01-17): Initial release with smart batching