E2E tests development for website (Selenium)

E2E Testing Development for Websites (Selenium)

Selenium WebDriver is the oldest standard for browser automation. It supports all major browsers, all programming languages, and integrates with TestNG, JUnit, pytest. Chosen when cross-browser compatibility is required via Selenium Grid or when legacy infrastructure already exists.

Selenium 4 + Python (pytest)

# requirements.txt
selenium>=4.0
pytest
pytest-html

# conftest.py
import pytest
from selenium import webdriver
from selenium.webdriver.chrome.options import Options

@pytest.fixture(scope='session')
def driver():
    options = Options()
    options.add_argument('--headless=new')
    options.add_argument('--no-sandbox')
    options.add_argument('--disable-dev-shm-usage')

    driver = webdriver.Chrome(options=options)
    driver.implicitly_wait(10)
    driver.set_window_size(1280, 900)

    yield driver
    driver.quit()

Basic Tests

# tests/test_login.py
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

class TestLogin:
    def test_valid_login(self, driver):
        driver.get('https://example.com/login')

        driver.find_element(By.CSS_SELECTOR, '[data-cy="email"]').send_keys('[email protected]')
        driver.find_element(By.CSS_SELECTOR, '[data-cy="password"]').send_keys('password123')
        driver.find_element(By.CSS_SELECTOR, '[data-cy="submit"]').click()

        wait = WebDriverWait(driver, 10)
        wait.until(EC.url_contains('/dashboard'))

        assert '/dashboard' in driver.current_url

    def test_invalid_login(self, driver):
        driver.get('https://example.com/login')

        driver.find_element(By.ID, 'email').send_keys('[email protected]')
        driver.find_element(By.ID, 'password').send_keys('wrongpass')
        driver.find_element(By.XPATH, '//button[@type="submit"]').click()

        error = WebDriverWait(driver, 5).until(
            EC.visibility_of_element_located((By.CSS_SELECTOR, '.error-message'))
        )
        assert 'Invalid' in error.text

Page Object Model

# pages/login_page.py
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

class LoginPage:
    URL = '/login'

    def __init__(self, driver):
        self.driver = driver
        self.wait = WebDriverWait(driver, 10)

    def open(self):
        self.driver.get(f'https://example.com{self.URL}')
        return self

    def enter_email(self, email: str):
        self.driver.find_element(By.ID, 'email').send_keys(email)
        return self

    def enter_password(self, password: str):
        self.driver.find_element(By.ID, 'password').send_keys(password)
        return self

    def submit(self):
        self.driver.find_element(By.CSS_SELECTOR, 'button[type=submit]').click()
        return self

    def get_error_message(self) -> str:
        element = self.wait.until(EC.visibility_of_element_located((By.CLASS_NAME, 'error')))
        return element.text

Selenium 4 + Java (TestNG)

// LoginTest.java
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.chrome.ChromeOptions;
import org.testng.Assert;
import org.testng.annotations.*;

public class LoginTest {
    private WebDriver driver;

    @BeforeClass
    public void setUp() {
        ChromeOptions options = new ChromeOptions();
        options.addArguments("--headless=new");
        driver = new ChromeDriver(options);
        driver.manage().window().setSize(new Dimension(1280, 900));
    }

    @Test
    public void testSuccessfulLogin() {
        driver.get("https://example.com/login");
        driver.findElement(By.id("email")).sendKeys("[email protected]");
        driver.findElement(By.id("password")).sendKeys("password123");
        driver.findElement(By.cssSelector("[type='submit']")).click();

        Assert.assertTrue(driver.getCurrentUrl().contains("/dashboard"),
            "Should redirect to dashboard after login");
    }

    @AfterClass
    public void tearDown() {
        if (driver != null) driver.quit();
    }
}

Selenium Grid — Parallel Execution

# docker-compose-grid.yml
services:
  selenium-hub:
    image: selenium/hub:4.18
    ports:
      - "4442:4442"
      - "4443:4443"
      - "4444:4444"

  chrome-node:
    image: selenium/node-chrome:4.18
    environment:
      SE_EVENT_BUS_HOST: selenium-hub
    depends_on: [selenium-hub]
    deploy:
      replicas: 3

  firefox-node:
    image: selenium/node-firefox:4.18
    environment:
      SE_EVENT_BUS_HOST: selenium-hub
    depends_on: [selenium-hub]

# Connecting to Grid
from selenium.webdriver.remote.webdriver import RemoteWebDriver

driver = RemoteWebDriver(
    command_executor='http://selenium-hub:4444/wd/hub',
    options=ChromeOptions()
)

Implementation Timeline

Setup + Page Objects + 30 test cases: 5–8 days.