XPath functions (contains, starts-with) in Selenium Java - Test Execution Trace

Test Overview

This test opens a web page and uses XPath functions contains and starts-with to find elements by partial attribute values. It verifies that the correct elements are found and clickable.

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 XPathFunctionsTest {
    WebDriver driver;
    WebDriverWait wait;

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

    @Test
    public void testContainsAndStartsWithXPath() {
        driver.get("https://example.com/testpage");

        // Find element with id containing 'submit'
        WebElement submitButton = wait.until(
            ExpectedConditions.presenceOfElementLocated(By.xpath("//button[contains(@id, 'submit')]")
            )
        );
        assertTrue(submitButton.isDisplayed());

        // Find element with class starting with 'nav-'
        WebElement navMenu = wait.until(
            ExpectedConditions.presenceOfElementLocated(By.xpath("//nav[starts-with(@class, 'nav-')]")
            )
        );
        assertTrue(navMenu.isDisplayed());

        // Click the submit button
        submitButton.click();
    }

    @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, ready to navigate	—	PASS
2	Navigate to https://example.com/testpage	Browser loads the test page with buttons and navigation menu	—	PASS
3	Wait until button with id containing 'submit' is present using XPath contains()	Button element with id like 'btn-submit' is found in DOM	Check that submit button is displayed	PASS
4	Wait until nav element with class starting with 'nav-' is present using XPath starts-with()	Navigation element with class like 'nav-main' is found in DOM	Check that navigation menu is displayed	PASS
5	Click the submit button	Submit button is clicked, triggering form submission or action	—	PASS
6	Test ends and browser closes	Browser window closes cleanly	—	PASS

Failure Scenario

Failing Condition: The XPath locator does not find the element because the attribute value does not contain or start with the expected string

Execution Trace Quiz - 3 Questions

Which XPath function is used to find elements by partial attribute value anywhere inside the string?

A ends-with()

B starts-with()

C contains()

D equals()

Key Result

Using XPath functions like contains() and starts-with() helps locate elements with partial attribute matches, making tests more flexible and resilient to small changes in attribute values.

Practice

1. Which XPath function would you use to locate elements whose attribute contains a specific substring anywhere within it?

easy

A. starts-with()

B. ends-with()

C. contains()

D. equals()

Solution

1. Step 1: Understand the purpose of contains()

   The contains() function checks if an attribute or text contains a given substring anywhere inside it.

2. Step 2: Compare with other functions

   starts-with() checks only the beginning, ends-with() is not standard XPath 1.0, and equals() is not an XPath function.

3. Final Answer:

   contains() -> Option C

4. Quick Check:

   Substring anywhere = contains() [OK]

Hint: Use contains() for substring anywhere inside attribute [OK]

Common Mistakes:

• Confusing contains() with starts-with()
• Using ends-with() which is not standard XPath 1.0
• Trying to use equals() as XPath function

2. Which of the following is the correct XPath syntax to find a button element whose id attribute starts with "submit"?

easy

A. //button[contains(@id, 'submit')]

B. //button[@id*='submit']

C. //button[@id^='submit']

D. //button[starts-with(@id, 'submit')]

Solution

1. Step 1: Identify the correct XPath function for 'starts with'

   The function starts-with() is used to check if an attribute starts with a substring.

2. Step 2: Check syntax correctness

   //button[starts-with(@id, 'submit')] is correct XPath syntax. Options B and C use invalid XPath operators.

3. Final Answer:

   //button[starts-with(@id, 'submit')] -> Option D

4. Quick Check:

   Starts with = starts-with() [OK]

Hint: Use starts-with(@attr, 'text') for prefix matching [OK]

Common Mistakes:

• Using contains() instead of starts-with() for prefix
• Using CSS selector syntax like ^= in XPath
• Incorrect function syntax or missing parentheses

3. Given the following HTML snippet:

<input type="text" id="user_email" value="[e-mail]"/>

What is the result of this XPath query?
//*[@id[contains(., 'user')]]

medium

A. Syntax error due to incorrect XPath function usage

B. Selects all elements with any id attribute

C. Selects the input element because its id contains 'user'

D. Selects no elements because 'user' is not in the value attribute

Solution

1. Step 1: Analyze the XPath syntax

   The XPath //*[@id[contains(., 'user')]] is syntactically incorrect because @id is an attribute node and cannot be used as a function or have predicates applied directly like this.

2. Step 2: Correct XPath syntax

   To check if the id attribute contains 'user', the correct XPath is //*[@id[contains(., 'user')]] is invalid; instead use //*[contains(@id, 'user')].

3. Final Answer:

   Syntax error due to incorrect XPath function usage -> Option A

4. Quick Check:

   Attribute predicates must be correctly formed [OK]

Hint: Use contains(@id, 'user') not @id[contains()] [OK]

Common Mistakes:

• Using predicates directly on attribute nodes
• Assuming . refers to attribute value in this context
• Incorrect predicate syntax

4. You wrote this XPath to find links starting with "http":
//a[contains(starts-with(@href, 'http'))]
Why does this XPath fail to find any elements?

medium

A. Because @href attribute is missing

B. Because contains() cannot wrap starts-with() function

C. Because starts-with() requires two arguments

D. Because the syntax is correct but no links start with 'http'

Solution

1. Step 1: Understand function nesting rules in XPath

   The contains() function expects two string arguments, but here it wraps starts-with() which returns a boolean, causing a syntax error.

2. Step 2: Correct usage

   Use either starts-with(@href, 'http') alone or contains(@href, 'http'), but not nested.

3. Final Answer:

   Because contains() cannot wrap starts-with() function -> Option B

4. Quick Check:

   Do not nest contains() and starts-with() [OK]

Hint: Do not nest XPath functions like contains(starts-with()) [OK]

Common Mistakes:

• Nesting contains() and starts-with() incorrectly
• Assuming starts-with() returns string for contains()
• Ignoring function argument requirements

5. You want to locate all <div> elements whose class attribute starts with "alert" but excludes those that contain "dismiss" anywhere in the class. Which XPath expression correctly achieves this?

hard

A. //div[starts-with(@class, 'alert') and not(contains(@class, 'dismiss'))]

B. //div[contains(@class, 'alert') and not(starts-with(@class, 'dismiss'))]

C. //div[starts-with(@class, 'alert') or not(contains(@class, 'dismiss'))]

D. //div[contains(@class, 'alert') or contains(@class, 'dismiss')]

Solution

1. Step 1: Use starts-with() to match class beginning

   The expression starts-with(@class, 'alert') selects elements whose class attribute begins with "alert".

2. Step 2: Exclude elements containing 'dismiss'

   The not(contains(@class, 'dismiss')) excludes elements whose class contains "dismiss" anywhere.

3. Step 3: Combine conditions with and

   Both conditions must be true, so use and to combine them.

4. Final Answer:

   //div[starts-with(@class, 'alert') and not(contains(@class, 'dismiss'))] -> Option A

5. Quick Check:

   Starts with alert AND no dismiss = //div[starts-with(@class, 'alert') and not(contains(@class, 'dismiss'))] [OK]

Hint: Combine starts-with() and not(contains()) with and [OK]

Common Mistakes:

• Using or instead of and causing wrong matches
• Mixing contains() and starts-with() incorrectly
• Forgetting to negate contains() for exclusion