Network interception (CDP) in Selenium Java - Test Execution Trace

Test Overview

This test uses Selenium with Chrome DevTools Protocol (CDP) to intercept network requests. It verifies that a specific API call is made and checks its response status.

Test Code - TestNG

Selenium Java

import org.openqa.selenium.By;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.devtools.DevTools;
import org.openqa.selenium.devtools.v114.network.Network;
import org.openqa.selenium.devtools.v114.network.model.Response;
import org.testng.Assert;
import org.testng.annotations.AfterClass;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.Test;

import java.util.Optional;
import java.util.concurrent.atomic.AtomicBoolean;

public class NetworkInterceptionTest {
    private ChromeDriver driver;
    private DevTools devTools;
    private AtomicBoolean apiCallMade;

    @BeforeClass
    public void setUp() {
        driver = new ChromeDriver();
        devTools = driver.getDevTools();
        devTools.createSession();
        apiCallMade = new AtomicBoolean(false);

        devTools.send(Network.enable(Optional.empty(), Optional.empty(), Optional.empty()));

        devTools.addListener(Network.responseReceived(), responseReceived -> {
            Response response = responseReceived.getResponse();
            if (response.getUrl().contains("/api/data")) {
                if (response.getStatus() == 200) {
                    apiCallMade.set(true);
                }
            }
        });
    }

    @Test
    public void testApiCallIsMade() {
        driver.get("https://example.com");
        driver.findElement(By.id("loadDataBtn")).click();

        // Wait briefly to allow network events to be captured
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }

        Assert.assertTrue(apiCallMade.get(), "Expected API call to /api/data was not made or did not return 200 status.");
    }

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

Execution Trace - 6 Steps

Step	Action	System State	Assertion	Result
1	Test starts and ChromeDriver launches browser	Browser window opens with DevTools session created and network interception enabled	-	PASS
2	Navigates to https://example.com	Page loads with a button having id 'loadDataBtn' visible	-	PASS
3	Finds element with id 'loadDataBtn' and clicks it	Button clicked, triggering network requests	-	PASS
4	Waits 2 seconds to capture network events	Network events captured including response for /api/data	Checks if response for /api/data has status 200	PASS
5	Asserts that API call to /api/data was made and returned 200	Assertion verifies apiCallMade is true	Assert.assertTrue(apiCallMade.get())	PASS
6	Test ends and browser closes	Browser window closes	-	PASS

Failure Scenario

Failing Condition: The API call to /api/data is not made or returns a status other than 200

Execution Trace Quiz - 3 Questions

What does the test verify about the network request?

A That the button with id 'loadDataBtn' is visible

B That the API call to /api/data is made and returns status 200

C That the page title contains 'Example'

D That the browser window opens successfully

Key Result

Using Chrome DevTools Protocol (CDP) with Selenium allows you to monitor and verify network requests directly, which is useful for testing API calls triggered by UI actions.