Recipe for exporting HAR files for load tests

[githubble01]

Hi All!

I've noticed an increasing interest in (re-)running scenarios as load test. For instance, Testable.io is allegedly able to do this, see https://docs.testable.io/getting-started/serenity.html.

So I'm looking for a way to have Serenity produce HAR files that can be subsequently used in load tests using for instance Gatling, see https://www.james-willett.com/gatling-load-testing-complete-guide/.

I think this could be accomplished using BeforeAWebdriverScenario and AfterAWebdriverScenario. The pseudo code below (based on browsermob-proxy ) creates one HAR file per testOutcome, making them easy to manage and run separately in Gatlin.

In an attempt to implement this recipe myself I failed miserably :(. Adding the capability in BeforeAWebdriverScenario went well, but I couldn't find a way to pass the BrowserMobProxy instance to the AfterAWebdriverScenario so I could write the har to file.

Simply misusing the capabilites capabilities.setCapability("MOBProxy", mobProxy ); in BeforeAWebdriverScenario and then doing BrowserMobProxy proxy = (BrowserMobProxy)RemoteDriver.of(driver).getCapabilities().getCapability("MOBProxy"); in the AfterAWebdriverScenario does not work.

First I tried with browsermob-proxy and then with serenity-browsermob-plugin .

I have also tried other approaches, such as #1656. The challenge of extracting the har file after a test outcome remains the same.

Any thoughts on how a har-export-recipe would look like?

Related to:

• How to capture HAR (network logs for running scenario) and any provision of attachment inside report index.html for corresponding scenarios. #1343
• How can I set browsermob proxy as capabilities to chrome driver? #1656

BR
Georg

public class MyCapabilityEnhancer implements BeforeAWebdriverScenario {
    @Override
    public DesiredCapabilities apply(EnvironmentVariables environmentVariables,
                                     SupportedWebDriver driver,
                                     TestOutcome testOutcome,
                                     DesiredCapabilities capabilities) {
       
       // 1. Start the mob proxy
        //BrowserMobProxy proxy = new BrowserMobProxyServer();
        //mobProxy.start(0);

        // 2. Enable more detailed HAR capture, if desired (see CaptureType for the complete list)
        //mobProxy.enableHarCaptureTypes(CaptureType.REQUEST_CONTENT, CaptureType.RESPONSE_CONTENT);

        // 3. Create a new HAR with the label "yahoo.com"
        //mobProxy.newHar(testOutcome.getStoryTitle());

        // 4. Get the Selenium proxy object
        //Proxy seleniumProxy = ClientUtil.createSeleniumProxy(mobProxy);

        // 5. Configure it as a desired capability
        //capabilities.setCapability(CapabilityType.PROXY, seleniumProxy);
    }
}

public class MyAfterScenario implements AfterAWebdriverScenario {
    public void apply(EnvironmentVariables environmentVariables,
                      TestOutcome testOutcome,
                      WebDriver driver) {

       // 1. Provide some way to extract the HAR (pseudo code..).
       // HarManager harManager = new HarManager(); 
       // Har har = harManager.getHarByStoryTitle(testOutcome.getStoryTitle());

       // 2. Write HAR to file
       // FileWriter fl  = new FileWriter("HAR-"+testOutcome.getStoryTitle()+".json");
       // har.writeTo(fl);*/
    }
}