Verify app behavior on emulator and real device

Preconditions (2)

Step 1: Launch the app on the emulator

Step 2: Navigate to the login screen

Step 3: Enter username 'testuser' and password 'Test@1234'

Step 4: Click the login button

Step 5: Verify the home screen is displayed

Step 6: Repeat steps 1-5 on the real device

✅ Expected Result: The app should successfully log in and display the home screen on both emulator and real device without errors.

Automation Requirements - Appium with Python

Assertions Needed:

Verify login button is clickable

Verify home screen element is visible after login

Best Practices:

Use explicit waits to wait for elements

Use Page Object Model to separate locators and actions

Handle device capabilities separately for emulator and real device

Automated Solution

Testing Fundamentals

from appium import webdriver
from appium.webdriver.common.appiumby import AppiumBy
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.username_field = (AppiumBy.ACCESSIBILITY_ID, "username_input")
        self.password_field = (AppiumBy.ACCESSIBILITY_ID, "password_input")
        self.login_button = (AppiumBy.ACCESSIBILITY_ID, "login_button")

    def enter_username(self, username):
        WebDriverWait(self.driver, 10).until(
            EC.visibility_of_element_located(self.username_field)
        ).send_keys(username)

    def enter_password(self, password):
        WebDriverWait(self.driver, 10).until(
            EC.visibility_of_element_located(self.password_field)
        ).send_keys(password)

    def tap_login(self):
        WebDriverWait(self.driver, 10).until(
            EC.element_to_be_clickable(self.login_button)
        ).click()

class HomePage:
    def __init__(self, driver):
        self.driver = driver
        self.home_screen_element = (AppiumBy.ACCESSIBILITY_ID, "home_screen")

    def is_displayed(self):
        return WebDriverWait(self.driver, 10).until(
            EC.visibility_of_element_located(self.home_screen_element)
        ) is not None

def create_driver(device_name, platform_version, app_path):
    desired_caps = {
        "platformName": "Android",
        "deviceName": device_name,
        "platformVersion": platform_version,
        "app": app_path,
        "automationName": "UiAutomator2"
    }
    return webdriver.Remote("http://localhost:4723/wd/hub", desired_caps)


def test_login_on_device(device_name, platform_version, app_path):
    driver = create_driver(device_name, platform_version, app_path)
    login_page = LoginPage(driver)
    home_page = HomePage(driver)

    login_page.enter_username("testuser")
    login_page.enter_password("Test@1234")
    login_page.tap_login()

    assert home_page.is_displayed(), f"Home screen not displayed on {device_name}"

    driver.quit()


if __name__ == "__main__":
    # Test on emulator
    test_login_on_device("emulator-5554", "13.0", "/path/to/app.apk")

    # Test on real device
    test_login_on_device("real_device_01", "12.0", "/path/to/app.apk")

This script uses Appium with Python to automate the login test on both emulator and real device.

We define LoginPage and HomePage classes to separate page elements and actions, following the Page Object Model.

The create_driver function sets up the driver with device-specific capabilities, so we can reuse it for emulator and real device by passing different parameters.

Explicit waits ensure the script waits for elements to be visible or clickable before interacting, avoiding timing issues.

The test_login_on_device function performs the login steps and asserts the home screen is visible, confirming successful login.

Finally, the script runs tests on both emulator and real device by calling test_login_on_device with appropriate device names and platform versions.

Common Mistakes - 3 Pitfalls

Using hardcoded sleep instead of explicit waits

Mixing locators inside test code instead of using Page Object Model

Using same device capabilities for emulator and real device

Bonus Challenge

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

Show Hint