Web performance testing with web driver
- 1. Web Performance Testing with WebDriver An integrated approach Michael Klepikov Make the Web Faster Team, Google developers.google.com/speed webpagetest.org
- 2. ■ +1s load => -7% conversion rate ■ Just better user experience ■ Mobile exacerbates slowness ■ 46% mobile users abandon after 10s Why is it important?
- 3. ■ WebPageTest.org ■ Waterfall chart ■ Simulated latency ■ Many iterations for statistical validity Page Load performance
- 4. Interactive scenarios ■ Multi-page ■ Login ■ Placing an order ■ AJAX is a better user experience
- 5. Test Systems Integration ■ WebPageTest is a separate system ■ Everyone has a custom toolchain ■ Hard to integrate ■ Not a seamless developer experience
- 6. ■ Standard WD API: ○ Session Capabilities ○ Logging ■ Easy to enable in existing tests ■ Fits well into existing toolchains Build it into WebDriver itself
- 7. ■ LoggingPreferences in WD capabilities // Ask Chrome to collect "performance" log DesiredCapabilities caps = DesiredCapabilities.chrome(); LoggingPreferences logPrefs = new LoggingPreferences(); logPrefs.enable("performance", Level.INFO); caps.setCapability(CapabilityType.LOGGING_PREFS, logPrefs); driver = new RemoteWebDriver("http://localhost:9515", caps); WD API: Create Driver
- 8. ■ Plain functional test, nothing special ■ Free magic for developers! ■ Pro tip: console.time()+timeEnd(), timeStamp() driver.get("http://www.google.com/"); WebElement element = driver.findElement(By.name("q")); element.sendKeys("GTAC 2013"); element.submit(); WD API: Run Test
- 9. ■ Not part of test per se, inject: ○ In tearDown() ○ Override WebDriver.quit() ○ WebDriver HTTP-JSON proxy log = driver.manage().logs().get("performance").getAll(); for (LogEntry entry : log) { // WebDriver LogEntry message is a JSON string JSONObject m = new JSONObject(entry.getMessage()); ... m.getString("webview") ... // Originating WebView id ... m.getJSONObject("message") ... // Raw DevTools event WD API: Get Performance Log
- 12. ■ No WD within instrumented intervals ■ Aggregate over multiple iterations! ■ Run frontend in maximum isolation ○ Mock/stub/fake backends ■ Use WebPageReplay Stable Repeatable Results