WebDriver tricks #2

Have you ever heard about WebDriver’s feature of capturing screenshots ? Now you know it can do it too ! Today we faced a problem of debugging WebDriver tests of remote continuous integration server. Since locally tests passed but failed on TeamCity we had a need to get some more debug info. After playing around with capturing API i’ve created utility class that is capturing browser screen and stores image into folder named as test class with image filename equals to running test method. For instance, you have class com.MyUnstableWebTest and method whenSmthHappensThenDoAction. When the utility method is called - image file with slightly the same as below name gonna be created.

Example name: /webtest-screenshot/com.MyUnstableWebTest/whenSmthHappensThenDoAction.png

Here’s sources of utility in Groovy. Please note that was tested only with FireFox web driver

package com.webtest

import org.apache.commons.io.FileUtils
import org.openqa.selenium.OutputType
import org.openqa.selenium.TakesScreenshot
import org.openqa.selenium.WebDriver

class ScreenshotUtils {
        static storeScreenshot(WebDriver webDriver,
                        def debugInfo = System.currentTimeMillis()) {
                def webTest = Thread.currentThread().stackTrace.find {
            it.className.endsWith("WebTest")
        }
        if (!webTest) throw new IllegalStateException("Called outside of WebTest")

        byte[] srcFile = ((TakesScreenshot) webDriver).getScreenshotAs(OutputType.BYTES)
        FileUtils.writeByteArrayToFile(
            new File("./webtest-screenshot/${webTest.className}/${webTest.methodName}_${debugInfo}.png"),
                        srcFile
                )
    }
}