BaseTest.java

package tests;

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.chrome.ChromeOptions;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import pages.LoginPage;
import pages.ProductsPage;

import java.time.Duration;
import java.util.HashMap;

public class BaseTest {

    WebDriver driver;
    LoginPage loginPage;
    ProductsPage productsPage;

    @BeforeMethod
    public void setup() {
        ChromeOptions options = new ChromeOptions();
        HashMap<String, Object> chromePrefs = new HashMap<>();
        chromePrefs.put("credentials_enable_service", false);
        chromePrefs.put("profile.password_manager_enabled", false);
        options.setExperimentalOption("prefs", chromePrefs);
        options.addArguments("--incognito");
        options.addArguments("--disable-notifications");
        options.addArguments("--disable-popup-blocking");
        options.addArguments("--disable-infobars");

        driver = new ChromeDriver(options);
        driver.manage().window().maximize();
        driver.manage().timeouts().implicitlyWait(Duration.ofSeconds(10));

        loginPage = new LoginPage(driver);
        productsPage = new ProductsPage(driver);
    }

    @AfterMethod (alwaysRun = true)
    public void close() {
        driver.quit();
    }
}

LoginPage.java

package pages;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;

public class LoginPage {

    WebDriver driver;

    By usernameField = By.id("user-name");
    By passwordField = By.id("password");
    By loginButton = By.id("login-button");
    By errorMessage = By.cssSelector("[data-test='error']");

    public LoginPage(WebDriver driver) {
        this.driver = driver;
    }

    public void open() {
        driver.get("https://www.saucedemo.com/");
    }

    public void login(String user, String password) {
        driver.findElement(usernameField).sendKeys(user);
        driver.findElement(passwordField).sendKeys(password);
        driver.findElement(loginButton).click();
    }

    public String getErrorMessage() {
        return driver.findElement(errorMessage).getText();
    }
}

LoginTest.java

package tests;

import org.openqa.selenium.By;
import org.testng.Assert;
import org.testng.annotations.Test;

public class LoginTest extends BaseTest{

    /*
        1. Логин с пустым паролем !!!
        2. Логин с пустым юзером !!!
        3. Логин с невалидными значениями !!!
        4. Позитивный логин !!!
     */

    @Test
    public void checkLogInWithEmptyPassword() {
        loginPage.open();
        loginPage.login("standard_user", "");
        Assert.assertEquals(loginPage.getErrorMessage(), "Epic sadface: Password is required");
    }

    @Test
    public void checkLogInWithEmptyUsername() {
        loginPage.open();
        loginPage.login("", "secret_sauce");
        Assert.assertEquals(loginPage.getErrorMessage(), "Epic sadface: Username is required");
    }

    @Test
    public void checkLogInWithNegativeValue() {
        loginPage.open();
        loginPage.login("test","test");
        Assert.assertEquals(loginPage.getErrorMessage(),
                "Epic sadface: Username and password do not match any user in this service");
    }

    @Test
    public void checkLogInWithPositiveValue() {
        loginPage.open();
        loginPage.login("standard_user","secret_sauce");
        Assert.assertTrue(productsPage.titleIsDisplayed());
    }
}

ProductsPage.java

package pages;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;

public class ProductsPage {

    WebDriver driver;
    By title = By.cssSelector("[data-test='title']");

    public ProductsPage(WebDriver driver) {
        this.driver = driver;
    }

    public boolean titleIsDisplayed() {
        return driver.findElement(title).isDisplayed();
    }
}