findElement by className in Selenium Java - Test Execution Trace

Test Overview

This test opens a web page, finds a button using its class name, clicks it, and verifies that a confirmation message appears.

Test Code - JUnit with Selenium WebDriver

Selenium Java

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.support.ui.ExpectedConditions;
import org.openqa.selenium.support.ui.WebDriverWait;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;

public class FindElementByClassNameTest {
    private WebDriver driver;
    private WebDriverWait wait;

    @BeforeEach
    public void setUp() {
        driver = new ChromeDriver();
        wait = new WebDriverWait(driver, 10);
    }

    @Test
    public void testClickButtonByClassName() {
        driver.get("https://example.com/testpage");
        WebElement button = wait.until(ExpectedConditions.presenceOfElementLocated(By.className("submit-btn")));
        button.click();
        WebElement message = wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("confirmation-message")));
        assertEquals("Submission successful", message.getText());
    }

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

Execution Trace - 6 Steps

Step	Action	System State	Assertion	Result
1	Test starts and Chrome browser opens	Chrome browser window is open and ready	—	PASS
2	Navigates to https://example.com/testpage	Page loads with a button having class 'submit-btn' and an empty confirmation message area	—	PASS
3	Waits until element with class name 'submit-btn' is present and finds the button	Button with class 'submit-btn' is located on the page	Element presence verified	PASS
4	Clicks the button found by class name	Button is clicked, triggering submission action	—	PASS
5	Waits until confirmation message with id 'confirmation-message' is visible	Confirmation message area is visible with text 'Submission successful'	Message text equals 'Submission successful'	PASS
6	Test ends and browser closes	Browser window is closed	—	PASS

Failure Scenario

Failing Condition: The button with class name 'submit-btn' is not found on the page

Execution Trace Quiz - 3 Questions

What Selenium method is used to find the button in this test?

A driver.findElement(By.className("submit-btn"))

B driver.findElement(By.id("submit-btn"))

C driver.findElement(By.name("submit-btn"))

D driver.findElement(By.tagName("button"))

Key Result

Always use explicit waits like WebDriverWait with ExpectedConditions to reliably find elements by class name before interacting with them.

Practice

1. What does the Selenium method findElement(By.className("btn-primary")) do in a test script?

easy

A. It finds an element by its HTML tag name "btn-primary".

B. It finds all web elements with the CSS class "btn-primary" on the page.

C. It finds the first web element with the CSS class "btn-primary" on the page.

D. It finds an element by its ID "btn-primary".

Solution

1. Step 1: Understand the method purpose

   The method findElement locates a single element on the page.

2. Step 2: Analyze the locator type

   Using By.className("btn-primary") targets elements with the CSS class "btn-primary".

3. Final Answer:

   It finds the first web element with the CSS class "btn-primary" on the page. -> Option C

4. Quick Check:

   findElement + className = first matching element [OK]

Hint: findElement with className returns first matching element [OK]

Common Mistakes:

• Confusing findElement with findElements (plural)
• Using className to find by ID or tag
• Expecting multiple elements returned

2. Which of the following is the correct syntax to find an element by class name "login-button" in Selenium Java?

easy

A. driver.findElement(By.classname("login-button"));

B. driver.findElement(By.className("login-button"));

C. driver.findElement(By.class_name("login-button"));

D. driver.findElement(By.class("login-button"));

Solution

1. Step 1: Recall correct method usage

   The correct method to locate by class name is By.className() with capital N.

2. Step 2: Check syntax correctness

   driver.findElement(By.className("login-button")); uses the exact correct syntax: By.className("login-button").

3. Final Answer:

   driver.findElement(By.className("login-button")); -> Option B

4. Quick Check:

   Correct method name is className with capital N [OK]

Hint: Use By.className with capital N for correct syntax [OK]

Common Mistakes:

• Using By.class instead of By.className
• Wrong method casing like class_name or classname
• Missing quotes around class name

3. Given the HTML snippet:

<button class="submit-btn primary">Submit</button>

What will the following code return?

WebElement btn = driver.findElement(By.className("primary"));
System.out.println(btn.getText());

medium

A. Submit

B. primary

C. submit-btn

D. NoSuchElementException

Solution

1. Step 1: Locate element by class name "primary"

   The button has class "primary" among others, so it matches.

2. Step 2: Get the text of the found element

   The getText() method returns the visible text inside the button, which is "Submit".

3. Final Answer:

   Submit -> Option A

4. Quick Check:

   findElement by className finds element, getText returns inner text [OK]

Hint: getText() returns visible text inside found element [OK]

Common Mistakes:

• Expecting class name as text output
• Confusing class attribute with element text
• Assuming exception if multiple classes present

4. What is wrong with this Selenium Java code snippet?

WebElement element = driver.findElement(By.className("btn primary"));

It tries to find an element with classes "btn" and "primary".

medium

A. The syntax is correct; it finds elements with both classes.

B. It should use findElements instead of findElement.

C. It should use By.id instead of By.className.

D. className locator cannot contain spaces; it matches only one class.

Solution

1. Step 1: Understand className locator rules

   The By.className locator accepts only a single class name without spaces.

2. Step 2: Identify the error in locator usage

   Using "btn primary" with space is invalid and causes an error; it cannot find elements with multiple classes this way.

3. Final Answer:

   className locator cannot contain spaces; it matches only one class. -> Option D

4. Quick Check:

   className accepts single class only, no spaces [OK]

Hint: Use single class name without spaces in className locator [OK]

Common Mistakes:

• Trying to find multiple classes with space-separated string
• Expecting findElement to accept compound class selectors
• Confusing className with CSS selector syntax

5. You want to click the first button with class "nav-item active" on a page. Which is the best way to do this using Selenium Java?

hard

A. driver.findElement(By.cssSelector(".nav-item.active")).click();

B. driver.findElement(By.className("nav-item active")).click();

C. driver.findElement(By.className("nav-item")).click();

D. driver.findElement(By.xpath("//button[@class='nav-item active']")).click();

Solution

1. Step 1: Understand limitation of className locator

   The By.className locator cannot handle multiple classes separated by spaces.

2. Step 2: Use CSS selector for multiple classes

   The CSS selector .nav-item.active matches elements with both classes and works correctly.

3. Step 3: Compare other options

   driver.findElement(By.className("nav-item active")).click(); is invalid due to space in className; driver.findElement(By.className("nav-item")).click(); matches only one class; driver.findElement(By.xpath("//button[@class='nav-item active']")).click(); uses XPath but is less concise.

4. Final Answer:

   driver.findElement(By.cssSelector(".nav-item.active")).click(); -> Option A

5. Quick Check:

   Use CSS selector for multiple classes, not className [OK]

Hint: Use CSS selector for multiple classes, not className [OK]

Common Mistakes:

• Using className with multiple classes separated by space
• Using only one class when both are needed
• Ignoring CSS selectors as a better alternative