Capturing browser logs with Selenium WebDriver using Java

Is there a way to capture browser logs while running automated test cases with Selenium? I found an article on how to capture JavaScript errors in Selenium. But that is just for Firefox and only for errors. I would like to get all the console logs.

I assume it is something in the lines of:

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.logging.LogEntries;
import org.openqa.selenium.logging.LogEntry;
import org.openqa.selenium.logging.LogType;
import org.openqa.selenium.logging.LoggingPreferences;
import org.openqa.selenium.remote.CapabilityType;
import org.openqa.selenium.remote.DesiredCapabilities;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

public class ChromeConsoleLogging {
    private WebDriver driver;


    @BeforeMethod
    public void setUp() {
        System.setProperty("webdriver.chrome.driver", "c:\\path\\to\\chromedriver.exe");        
        DesiredCapabilities caps = DesiredCapabilities.chrome();
        LoggingPreferences logPrefs = new LoggingPreferences();
        logPrefs.enable(LogType.BROWSER, Level.ALL);
        caps.setCapability(CapabilityType.LOGGING_PREFS, logPrefs);
        driver = new ChromeDriver(caps);
    }

    @AfterMethod
    public void tearDown() {
        driver.quit();
    }

    public void analyzeLog() {
        LogEntries logEntries = driver.manage().logs().get(LogType.BROWSER);
        for (LogEntry entry : logEntries) {
            System.out.println(new Date(entry.getTimestamp()) + " " + entry.getLevel() + " " + entry.getMessage());
            //do something useful with the data
        }
    }

    @Test
    public void testMethod() {
        driver.get("http://mypage.com");
        //do something on page
        analyzeLog();
    }
}

Source : https://stackoverflow.com/questions/18261338/get-chromes-console-log

In a more concise way, you can do:

LogEntries logs = driver.manage().logs().get(LogType.BROWSER);

For me it worked wonderfully for catching JS errors in console. Then you can add some verification for its size. For example, if it is > 0, add some error output.

As a non-java selenium user, here is the python equivalent to Margus's answer:

from selenium import webdriver
from selenium.webdriver.common.desired_capabilities import DesiredCapabilities    

class ChromeConsoleLogging(object):

    def __init__(self, ):
        self.driver = None

    def setUp(self, ):
        desired = DesiredCapabilities.CHROME
        desired ['loggingPrefs'] = { 'browser':'ALL' }
        self.driver = webdriver.Chrome(desired_capabilities=desired)

    def analyzeLog(self, ):
        data = self.driver.get_log('browser')
        print(data)

    def testMethod(self, ):
        self.setUp()
        self.driver.get("http://mypage.com")
        self.analyzeLog()

Reference

Edit: Keeping Python answer in this thread because it is very similar to the Java answer and this post is returned on a Google search for the similar Python question

A less elegant solution is taking the log 'manually' from the user data dir:

1. Set the user data dir to a fixed place:

   options = new ChromeOptions();
   capabilities = DesiredCapabilities.chrome();
   options.addArguments("user-data-dir=/your_path/");
   capabilities.setCapability(ChromeOptions.CAPABILITY, options);
   

2. Get the text from the log file chrome_debug.log located in the path you've entered above.

I use this method since RemoteWebDriver had problems getting the console logs remotely. If you run your test locally that can be easy to retrieve.

Adding LoggingPreferences to "goog:loggingPrefs" properties with the Chrome Driver options can help to fetch the Browser console logs for all Log levels.

ChromeOptions options = new ChromeOptions();	
LoggingPreferences logPrefs = new LoggingPreferences();
logPrefs.enable(LogType.BROWSER, Level.ALL);
options.setCapability("goog:loggingPrefs", logPrefs);
WebDriver driver = new ChromeDriver(options);

Starting with Firefox 65 an about:config flag exists now so console API calls like console.log() land in the output stream and thus the log file (see (https://github.com/mozilla/geckodriver/issues/284#issuecomment-458305621).

profile = new FirefoxProfile();
profile.setPreference("devtools.console.stdout.content", true);

Driver manager logs can be used to get console logs from browser and it will help to identify errors appears in console.

   import org.openqa.selenium.logging.LogEntries;
   import org.openqa.selenium.logging.LogEntry;
    
    public List<LogEntry> getBrowserConsoleLogs()
    {
    LogEntries log= driver.manage().logs().get("browser")
    List<LogEntry> logs=log.getAll();
    return logs;
    }

Before launching webdriver, we just set this environment variable to let chrome generate it:

export CHROME_LOG_FILE=$(pwd)/tests/e2e2/logs/client.log

Add cast RemoteWebDriver to driver initialize and you will have the .setLogLevel method:

import java.util.logging.Level;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.remote.RemoteWebDriver;

public class PrintLogTest {
	public static void main(String[] args) {
		System.setProperty("webdriver.chrome.driver", "/Users/.../chromedriver");
		WebDriver driver = new ChromeDriver();
		
		//here
		((RemoteWebDriver) driver).setLogLevel(Level.INFO);
		
		driver.get("https://google.com/");
		driver.findElement(By.name("q")).sendKeys("automation test");
		driver.quit();
	}
}

Example output:

Jun 15, 2020 4:27:04 PM org.openqa.selenium.remote.RemoteWebDriver log
INFO: Executing: get [430aec21a9beb6340a4185c4ea6a693d, get {url=https://google.com/}]
Jun 15, 2020 4:27:06 PM org.openqa.selenium.remote.RemoteWebDriver log
INFO: Executed: [430aec21a9beb6340a4185c4ea6a693d, get {url=https://google.com/}]
Jun 15, 2020 4:27:06 PM org.openqa.selenium.remote.RemoteWebDriver log
INFO: Executing: findElement [430aec21a9beb6340a4185c4ea6a693d, findElement {using=name, value=q}]
Jun 15, 2020 4:27:06 PM org.openqa.selenium.remote.RemoteWebDriver log
INFO: Executed: [430aec21a9beb6340a4185c4ea6a693d, findElement {using=name, value=q}]
...
...

At least I've tried it on ChromeDriver() and FirefoxDriver() and it working fine.