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Krishnan Mahadevan
Krishnan Mahadevan
18 November, 2016

Testcase specific logs for a Selenium project

Testcase specific logs for a Selenium project

Problem statement:

You would like to have a separate log file for every testcase so that if there are failures, its very easy for you to be able to debug and find out failures.

For going through this, I am going to be using a selenium based test as an example.

Selenium has a webdriver implementation called EventFiringWebDriver using which you can eavesdrop into the webdriver events. (For more information on eavesdropping into webdriver events please take a look at my blog post here

I am going to be using the following to explain this :

  1. Sl4fj (the logging framework)
  2. Maven (the build tool)
  3. TestNG (the test runner)

You would first need to add a dependency to sl4j as shown below (slf4j has many variants. We are just going to stick to using logback)

<!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-classic -->
<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-classic</artifactId>
    <version>1.0.3</version>
</dependency>

For more information on getting started with slf4j please refer here.

We now need to create a logback.xml file as shown below.

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
 
    <appender name="SIFT" class="ch.qos.logback.classic.sift.SiftingAppender">
        <discriminator>
            <key>userid</key>
            <defaultValue>unknown</defaultValue>
        </discriminator>
        <sift>
            <appender name="FILE-${userid}" class="ch.qos.logback.core.FileAppender">
                <file>${fileName}.log</file>
                <layout class="ch.qos.logback.classic.PatternLayout">
                    <pattern>%d{HH:mm:ss:SSS} | %-5level | %thread | %logger{20} | %msg%n%rEx</pattern>
                </layout>
            </appender>
        </sift>
    </appender>
 
    <root level="ALL">
        <appender-ref ref="SIFT" />
    </root>
</configuration>

For more information you can refer to this blog post here.

You now can build an implementation of org.openqa.selenium.support.events.WebDriverEventListener (this is the listener we will be injecting into EventFiringWebDriver) as shown below.

public class LogAwareWebDriverEventListener extends AbstractWebDriverEventListener {
 
    @Override
    public void beforeNavigateTo(String url, WebDriver driver) {
        LoggerFactory.getLogger(getClass()).info("Loading url " + url);
    }
 
    public void bindLogName(String log, String folderName) {
        String path = new File(folderName).getAbsolutePath() + File.separator;
        MDC.put("fileName", path+log);
    }
 
    public void unbind() {
        MDC.remove("fileName");
    }
}

Now that we have all the pieces required, lets go ahead and create our test case, which looks like below.

public class ManyTestCases {
    @Test
    public void testMethod1() {
        runTest("http://www.google.com");
    }
 
    @Test
    public void testMethod2() {
        runTest("http://www.yahoo.com");
    }
 
    private void runTest(String url) {
        ChromeDriver cd = new ChromeDriver();
        EventFiringWebDriver driver = new EventFiringWebDriver(cd);
        LogAwareWebDriverEventListener listener = new LogAwareWebDriverEventListener();
        String outputFolder = Reporter.getCurrentTestResult().getTestContext().getSuite().getOutputDirectory();
        listener.bindLogName(Reporter.getCurrentTestResult().getName(), outputFolder);
        driver.register(listener);
        driver.get(url);
        driver.quit();
        listener.unbind();
    }
}

That’s it! Now when you run your tests, your test method specific log files will be created in the default output directory of TestNG.

If running from an IDE, you should see the log files under test-output folder and if you are running them via maven you should see them under target/surefire-reports folder.

For any queries, log an issue here.

Tags: TestNG, WebDriver