majiayu000 Frontend Testing Skill
Proposito
Testa aplicacoes web locais e remotas usando Playwright:
- Screenshots: Captura visual para validacao
- E2E Tests: Testes end-to-end automatizados
- Browser Logs: Analise de erros e warnings
- Accessibility: Validacao basica de a11y
Principios de Design
1. Reconnaissance-Then-Action
Baseado no padrao do webapp-testing da Anthropic:
1. Navigate → Ir para a pagina
2. Wait → Aguardar network idle
3. Capture → Screenshot ou DOM
4. Discover → Identificar seletores do DOM renderizado
5. Interact → Executar acoes com seletores descobertos
2. Server Lifecycle Management
Gerenciar servidor local automaticamente:
# Inicia servidor, executa teste, encerra servidor
python scripts/with_server.py --server "npm run dev" --port 3000 -- pytest tests/
3. Never Hardcode Selectors
Sempre descobrir seletores do DOM real, nunca assumir.
Comandos
/frontend-test {url}
Executa suite de testes E2E.
/frontend-test http://localhost:3000
/frontend-test https://staging.example.com
/frontend-screenshot {url} {nome}
Captura screenshot de uma pagina.
/frontend-screenshot http://localhost:3000 homepage
/frontend-screenshot http://localhost:3000/login login-page
Output: .agentic_sdlc/projects/{id}/screenshots/{nome}.png
/frontend-check {url}
Verifica saude basica da aplicacao.
/frontend-check http://localhost:3000
Verifica:
- Pagina carrega sem erros
- Console sem erros criticos
- Links nao quebrados
- Performance basica
Workflow de Testes
Setup com Servidor Local
# Single server
python scripts/with_server.py \
--server "npm run dev" \
--port 5173 \
-- python scripts/run_tests.py
# Multiple servers (frontend + backend)
python scripts/with_server.py \
--server "cd backend && python server.py" --port 3000 \
--server "cd frontend && npm run dev" --port 5173 \
-- python scripts/run_tests.py
Captura de Screenshot
from playwright.sync_api import sync_playwright
with sync_playwright() as p:
browser = p.chromium.launch()
page = browser.new_page()
page.goto("http://localhost:3000")
page.wait_for_load_state("networkidle")
page.screenshot(path="screenshot.png", full_page=True)
browser.close()
Teste E2E Basico
def test_login_flow(page):
page.goto("http://localhost:3000/login")
page.wait_for_load_state("networkidle")
# Descobrir seletores do DOM real
page.fill('[data-testid="email"]', 'test@example.com')
page.fill('[data-testid="password"]', 'password123')
page.click('[data-testid="submit"]')
# Verificar redirecionamento
page.wait_for_url("**/dashboard")
assert "dashboard" in page.url
Integracao com SDLC
Phase 6 (Quality) - qa-analyst
quality_gate:
frontend_tests:
required: true
criteria:
- "E2E tests passing"
- "No console errors"
- "Screenshots captured for review"
commands:
- "/frontend-test http://localhost:3000"
- "/frontend-screenshot http://localhost:3000 homepage"
Phase 7 (Release) - Evidencias
release_artifacts:
screenshots:
- homepage.png
- login-page.png
- dashboard.png
test_reports:
- e2e-results.json
Dependencias
Obrigatorias
# Python
pip install playwright pytest-playwright
# Browser
playwright install chromium
Opcionais
# Para testes visuais
pip install pixelmatch pillow
# Para acessibilidade
pip install axe-playwright-python
Verificar Instalacao
python scripts/check_deps.py
Boas Praticas
1. Sempre Aguardar Network Idle
page.goto(url)
page.wait_for_load_state("networkidle") # OBRIGATORIO
2. Usar data-testid
Preferir seletores data-testid sobre classes CSS:
<!-- BOM -->
<button data-testid="submit-btn">Submit</button>
<!-- EVITAR -->
<button class="btn btn-primary submit">Submit</button>
3. Capturar Logs do Browser
page.on("console", lambda msg: print(f"[{msg.type}] {msg.text}"))
page.on("pageerror", lambda err: print(f"[ERROR] {err}"))
4. Organizar Screenshots
.agentic_sdlc/projects/{id}/
└── screenshots/
├── before/ # Estado inicial
├── after/ # Apos mudancas
└── regression/ # Comparacao visual
Anti-Patterns
NAO Fazer
# ❌ Hardcoded selectors sem verificar DOM
page.click("#submit-btn")
# ❌ Sleep ao inves de wait
import time
time.sleep(5)
# ❌ Ignorar erros de console
# (nao configurar handler)
Fazer
# ✅ Descobrir seletor do DOM
submit = page.locator('[data-testid="submit"]')
if submit.count() > 0:
submit.click()
# ✅ Wait explicito
page.wait_for_selector('[data-testid="result"]')
# ✅ Capturar todos os logs
errors = []
page.on("pageerror", lambda e: errors.append(e))
Troubleshooting
"Browser nao instalado"
playwright install chromium
# Ou todos os browsers
playwright install
"Timeout ao carregar pagina"
Aumentar timeout:
page.goto(url, timeout=60000) # 60 segundos
"Servidor nao iniciou"
Verificar porta:
lsof -i :3000
# Se ocupada, usar outra porta
python scripts/with_server.py --server "npm run dev" --port 3001 ...
"Screenshot em branco"
Aguardar conteudo:
page.wait_for_selector("main", state="visible")
page.screenshot(path="screenshot.png")