selenium

When to use this skill

Use this skill whenever the user wants to:

• Write or maintain browser automation tests with Selenium WebDriver
• Locate elements using CSS selectors, IDs, or relative locators
• Implement explicit and implicit waits for robust test execution
• Run tests in headless mode or across browsers via Selenium Grid
• Integrate Selenium tests into CI/CD pipelines

How to use this skill

Workflow

1. Set up the environment: install browser drivers (ChromeDriver/GeckoDriver) or use Selenium 4 Manager
2. Write test scripts: navigate, find elements, interact, and assert
3. Add waits and error handling: use explicit waits instead of sleep
4. Run in CI: configure headless mode or Grid; generate reports

1. Basic Test (Python)

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

driver = webdriver.Chrome()
driver.get("https://example.com/login")

# Explicit wait for element
wait = WebDriverWait(driver, 10)
username = wait.until(EC.presence_of_element_located((By.ID, "username")))
username.send_keys("testuser")

driver.find_element(By.ID, "password").send_keys("secret")
driver.find_element(By.CSS_SELECTOR, "button[type='submit']").click()

# Assert login success
assert "Dashboard" in driver.title

driver.quit()

2. Basic Test (Java)

WebDriver driver = new ChromeDriver();
driver.get("https://example.com/login");

WebDriverWait wait = new WebDriverWait(driver, Duration.ofSeconds(10));
WebElement username = wait.until(ExpectedConditions.presenceOfElementLocated(By.id("username")));
username.sendKeys("testuser");

driver.findElement(By.id("password")).sendKeys("secret");
driver.findElement(By.cssSelector("button[type='submit']")).click();

assertTrue(driver.getTitle().contains("Dashboard"));
driver.quit();

3. Headless Mode

from selenium.webdriver.chrome.options import Options

options = Options()
options.add_argument("--headless")
options.add_argument("--no-sandbox")
driver = webdriver.Chrome(options=options)

Best Practices

• Use explicit waits (WebDriverWait) instead of time.sleep for reliable tests
• Prefer ID, CSS selector, or relative locators over fragile XPath expressions
• Keep test cases independent and repeatable; capture screenshots on failure
• Store sensitive data (URLs, credentials) in configuration files or environment variables
• Use Selenium Grid for parallel execution; ensure browser and driver versions match

Resources

• Official documentation: https://www.selenium.dev/documentation/
• Selenium Grid: https://www.selenium.dev/documentation/grid/

Keywords

selenium, WebDriver, browser automation, E2E, end-to-end testing, headless, Selenium Grid, ChromeDriver, explicit wait, CSS selector