Why synchronization eliminates timing failures in Selenium Java - Test Execution Impact

Test Overview

This test checks that synchronization using explicit waits prevents timing failures by waiting for an element to be visible before clicking it.

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.assertTrue;
import java.time.Duration;

public class SynchronizationTest {
    WebDriver driver;
    WebDriverWait wait;

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

    @Test
    public void testClickAfterElementVisible() {
        driver.get("https://example.com/delayed_button");
        // Wait until the button is visible
        WebElement button = wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("delayedButton")));
        button.click();
        // Verify that clicking the button shows a success message
        WebElement message = wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("successMessage")));
        assertTrue(message.isDisplayed(), "Success message should be displayed after clicking the button");
    }

    @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	Browser window is open, ready to navigate	-	PASS
2	Navigates to https://example.com/delayed_button	Page loads with a button that appears after a delay	-	PASS
3	Waits explicitly until the button with id 'delayedButton' is visible	Button becomes visible after some seconds	Checks that the button is visible before proceeding	PASS
4	Clicks the visible button	Button is clicked, triggering a success message display	-	PASS
5	Finds the success message element with id 'successMessage'	Success message is present on the page	Verifies that the success message is displayed	PASS
6	Test ends and browser closes	Browser window is closed	-	PASS

Failure Scenario

Failing Condition: If synchronization is not used, the test tries to click the button before it is visible

Execution Trace Quiz - 3 Questions

What does the explicit wait in this test ensure?

A The button is visible before clicking

B The page URL is correct

C The browser window is maximized

D The success message is hidden

Key Result

Using explicit waits to synchronize test steps with the web page state prevents timing failures and makes tests more reliable.