Verify user login functionality with organized test structure

Preconditions (2)

Step 1: Open the login page at http://localhost:5000/login

Step 2: Enter 'testuser' in the username field

Step 3: Enter 'Test@1234' in the password field

Step 4: Click the login button

Step 5: Verify that the user is redirected to the dashboard page at /dashboard

Step 6: Verify that the dashboard page contains the text 'Welcome, testuser!'

✅ Expected Result: User successfully logs in and sees the dashboard welcome message

Automation Requirements - pytest with Selenium WebDriver

Assertions Needed:

Assert current URL is http://localhost:5000/dashboard

Assert page contains text 'Welcome, testuser!'

Best Practices:

Use Page Object Model to separate page interactions

Use explicit waits to handle dynamic page loading

Organize tests in folders and modules by feature

Use pytest fixtures for setup and teardown

Automated Solution

PyTest

import pytest
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

class LoginPage:
    def __init__(self, driver):
        self.driver = driver
        self.url = "http://localhost:5000/login"
        self.username_input = (By.ID, "username")
        self.password_input = (By.ID, "password")
        self.login_button = (By.ID, "login-btn")

    def load(self):
        self.driver.get(self.url)

    def login(self, username, password):
        WebDriverWait(self.driver, 10).until(
            EC.visibility_of_element_located(self.username_input)
        )
        self.driver.find_element(*self.username_input).send_keys(username)
        self.driver.find_element(*self.password_input).send_keys(password)
        self.driver.find_element(*self.login_button).click()

class DashboardPage:
    def __init__(self, driver):
        self.driver = driver
        self.welcome_text_locator = (By.XPATH, "//h1[contains(text(), 'Welcome,')]")

    def is_loaded(self):
        return WebDriverWait(self.driver, 10).until(
            EC.url_contains("/dashboard")
        )

    def get_welcome_text(self):
        return self.driver.find_element(*self.welcome_text_locator).text

@pytest.fixture
def driver():
    driver = webdriver.Chrome()
    driver.implicitly_wait(5)
    yield driver
    driver.quit()

@pytest.mark.usefixtures("driver")
def test_user_can_login(driver):
    login_page = LoginPage(driver)
    dashboard_page = DashboardPage(driver)

    login_page.load()
    login_page.login("testuser", "Test@1234")

    assert dashboard_page.is_loaded(), "Dashboard page did not load"
    welcome_text = dashboard_page.get_welcome_text()
    assert welcome_text == "Welcome, testuser!", f"Unexpected welcome text: {welcome_text}"

This test script uses pytest and Selenium WebDriver to automate the login test.

We use the Page Object Model to keep page details separate from test logic. LoginPage handles login page actions, and DashboardPage handles dashboard checks.

Explicit waits ensure elements are ready before interacting, avoiding flaky tests.

The driver fixture sets up and tears down the browser cleanly.

The test test_user_can_login loads the login page, performs login, then asserts the dashboard URL and welcome message.

This organized structure helps tests stay clear and easy to maintain as the project grows.

Common Mistakes - 4 Pitfalls

{'mistake': 'Hardcoding waits like time.sleep instead of using explicit waits', 'why_bad': 'It makes tests slow and flaky because the wait time may be too short or too long.', 'correct_approach': "Use Selenium's explicit waits (WebDriverWait) to wait only as long as needed for elements."}

Mixing test logic and page interaction code in the same function

Not quitting the browser after tests

Using brittle locators like absolute XPaths

Bonus Challenge

Now add data-driven testing with 3 different username and password combinations

Show Hint