Implicit and Explicit waits in Selenium WebDriwer, how to.
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This document discusses the proper use of implicit and explicit waits in Selenium. It notes that implicit waits should be used to wait for element presence, while explicit waits should not be used for this. Implicit wait timeouts should be set lower than explicit wait timeouts. Using implicit and explicit waits together requires care to avoid conflicts between the timeouts. The document provides examples of how to set up waits correctly and what exceptions may occur in different scenarios. It also briefly mentions alternatives to WebDriver waits like using Selenide.
Implicit and Explicit waits in Selenium WebDriwer, how to.
- 1. YOU ARE DOING IT WRONG ALL THE TIME The Great Battle of Selenium Waits
- 2. Speaker Info Yaroslav Pernerovsky, Ukraine Automation Team Lead, GlobalLogic /in/yaroslav-pernerovsky-0559b51 /yaroslav.pernerovsky
- 3. Problem Implicit waits are a terrible mistake I've made and I apologies for them Simon Stewart, d Creator of WebDriver
- 4. Problem
- 5. Problem
- 6. Problem
- 7. Problem
- 8. @Test public void simpleAction() { driver.get("http://www.google.com"); driver.findElement(By.name("q")) .sendKeys("Search String" + Keys.ENTER); driver.findElement(By.cssSelector("h3.r")) .click(); } Real Case
- 9. Real Case
- 10. Real Case
- 11. Custom Wait while(true) { if (System.currentTimeMillis()-startTime > timeout){ throw new TimeoutException(); } try { return driver.findElement(locator); } catch (NoSuchElementException e) {} Thread.sleep(500); }
- 12. WebDriver waits chromedriver geckodriver IEDriverServer Implicit waits hereExplicit waits here
- 13. Implicit Waits driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS); driver.manage().timeouts().pageLoadTimeout(10, TimeUnit.SECONDS); driver.manage().timeouts().setScriptTimeout(10, TimeUnit.SECONDS);
- 14. Implicit Waits driver.findElement() • Wait until element appeared in DOM • Return first element if more than one present • Throws NoSuchElementException
- 15. Implicit Waits driver.findElements() • Wait until at least one element appeared in DOM • Return collection of all found elements • Return empty collection if no elements found
- 16. Implicit Waits Common Issue public boolean isElementPresent(By locator) { return driver.findElements(locator).size() > 0; } if (isElementPresent(login)) driver.findElement(login).click(); if (!isElementPresent(login)) driver.findElement(logout).click();
- 17. Implicit Waits Common Issue public boolean isElementNotPresent(By locator) { driver.manage().timeouts() .implicitlyWait(0, TimeUnit.SECONDS); boolean result= driver.findElements(locator).size() > 0; driver.manage().timeouts() .implicitlyWait(defaultTimeOut, TimeUnit.SECONDS); return result; }
- 18. Explicit Waits WebDriverWait wait = new WebDriverWait(driver, 10); wait.until(driver -> driver.findElement(locator)); wait.until(ExpectedConditions .presenceOfElementLocated(locator)); http://seleniumhq.github.io/selenium/docs/api/java/org/openqa/selenium/support/ui/ExpectedConditions.html
- 20. WebDriver Exceptions and RemoteWebDriver
- 23. What if? wait = new WebDriverWait(driver,5); driver.manage().timeouts() .implicitlyWait(10, TimeUnit.SECONDS); wait.until(ExpectedConditions .presenceOfElementLocated(locator); How long will Selenium wait ? 5 15 C: 10 25
- 24. Why? public static ExpectedCondition<WebElement> presenceOfElementLocated(final By locator) { return new ExpectedCondition<WebElement>() { @Override public WebElement apply(WebDriver driver) { return findElement(locator, driver); } ... private static WebElement findElement(By by, WebDriver driver) { try { return driver.findElements(by).stream().findFirst().orElseThrow( () -> new NoSuchElementException("Cannot locate an element using " + by)); } catch (NoSuchElementException e) { throw e; } catch (WebDriverException e) { log.log(Level.WARNING, String.format("WebDriverException thrown by findElement(%s)", by), e); throw e; } }
- 25. What if? wait = new WebDriverWait(driver,5); driver.manage().timeouts() .implicitlyWait(10, TimeUnit.SECONDS); wait.until(ExpectedConditions .presenceOfElementLocated(locator); Which exception will be thrown ? A: Timeout NoSuchElement Both None
- 26. What if? wait = new WebDriverWait(driver,10); driver.manage().timeouts() .implicitlyWait(5, TimeUnit.SECONDS); wait.until(ExpectedConditions .presenceOfElementLocated(locator); How long will Selenium wait ? 5 15 C: 10 25
- 27. What if? wait = new WebDriverWait(driver,11); driver.manage().timeouts() .implicitlyWait(5, TimeUnit.SECONDS); wait.until(ExpectedConditions .presenceOfElementLocated(locator); How long will Selenium wait ? 5 B: 15 11 26
- 28. What if? wait = new WebDriverWait(driver,5); driver.manage().timeouts() .implicitlyWait(10, TimeUnit.SECONDS); wait.until(ExpectedConditions.not( ExpectedConditions.presenceOfElementLocated(locator)); How long will Selenium wait if element is present? A: 5 15 10 25
- 29. What if? wait = new WebDriverWait(driver,5); driver.manage().timeouts() .implicitlyWait(10, TimeUnit.SECONDS); wait.until(ExpectedConditions.not( ExpectedConditions.presenceOfElementLocated(locator)); How long will Selenium wait if element is not present? C: 5 15 10 25
- 30. Coexistence rules Use Implicit wait for element presence Do not use Explicit wait for element presence Always set implicit timeout lower than explicit Timeouts must be multiple to each other Take special care to 'not present' conditions
- 31. Side-by-Side comparison Client Side (500ms) Can wait for anything Explicit usage TimeoutException Multiple network calls Explicit Implicit Driver Side (100ms) Element appeared in DOM Works automatically NoSuchElementException Single network call
- 32. Few words about Selenide WebDriver Implicit Wait not used at all Custom implicit waits on client side Default polling interval - 100ms Remote WebDriver traffic issues
- 33. Questions