Remove scroller.js and let Selenium do its thing (#2161)

Remove custom JS to handle scrolling and let selenium do its thing.

Selenium handles scrolling elements nativly before clicking / sending
text etc as part of the WebDriver spec.

https://www.w3.org/TR/webdriver2/#element-click
> The Element Click command scrolls into view the element if it is not already pointer-interactable, and clicks its in-view center point.

Author: jtnord

src/main/java/org/jenkinsci/test/acceptance/po/ConfigurablePageObject.java

@@ -33,6 +33,7 @@
 import java.util.concurrent.Callable;
 import org.jenkinsci.test.acceptance.selenium.Scroller;
 import org.openqa.selenium.By;
+import org.openqa.selenium.Keys;
 import org.openqa.selenium.WebElement;
 
 /**
@@ -132,6 +133,12 @@ public void ensureConfigPage() {
 
     public void save() {
         WebElement e = find(SAVE_BUTTON);
+        // form validation may happen if a currently focused element loosed focus
+        // this can cause the position of the save button to change between the mouse down and mouse up
+        // causing the click to be lost.
+        // see https://github.com/mozilla/geckodriver/issues/2234 for more information
+        // give the save button focus by sending it a "shift key" which is mostly harmless
+        e.sendKeys(Keys.SHIFT);
         e.click();
         waitFor(e).until(CapybaraPortingLayerImpl::isStale);
     }

src/main/java/org/jenkinsci/test/acceptance/selenium/Scroller.java

@@ -4,19 +4,13 @@
 import java.io.InputStream;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
-import java.time.Duration;
-import java.util.Objects;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import org.jenkinsci.test.acceptance.junit.Wait;
-import org.openqa.selenium.By;
 import org.openqa.selenium.JavascriptExecutor;
 import org.openqa.selenium.NoAlertPresentException;
-import org.openqa.selenium.TimeoutException;
 import org.openqa.selenium.UnhandledAlertException;
 import org.openqa.selenium.WebDriver;
 import org.openqa.selenium.WebDriver.Navigation;
-import org.openqa.selenium.WebElement;
 import org.openqa.selenium.support.events.WebDriverListener;
 
 /**
@@ -74,39 +68,20 @@
  * @author Kohsuke Kawaguchi
  */
 public class Scroller implements WebDriverListener {
-
     private final Logger LOGGER = Logger.getLogger(Scroller.class.getName());
 
-    private final String scrollJs;
     private final String disableStickyElementsJs;
     private final WebDriver driver;
 
     public Scroller(WebDriver driver) {
         this.driver = driver;
-        try (InputStream scroller = getClass().getResourceAsStream("scroller.js");
-                InputStream sticky = getClass().getResourceAsStream("disable-sticky-elements.js")) {
-            scrollJs = new String(scroller.readAllBytes(), StandardCharsets.UTF_8);
+        try (InputStream sticky = getClass().getResourceAsStream("disable-sticky-elements.js")) {
             disableStickyElementsJs = new String(sticky.readAllBytes(), StandardCharsets.UTF_8);
         } catch (IOException e) {
             throw new Error("Failed to load the JavaScript file", e);
         }
     }
 
-    @Override
-    public void beforeClick(WebElement element) {
-        scrollIntoView(element);
-    }
-
-    @Override
-    public void beforeSendKeys(WebElement element, CharSequence[] keysToSend) {
-        scrollIntoView(element);
-    }
-
-    @Override
-    public void beforeClear(WebElement element) {
-        scrollIntoView(element);
-    }
-
     @Override
     public void afterGet(WebDriver driver, String url) {
         disableStickyElementsIgnoringDialogs();
@@ -150,34 +125,4 @@ public void disableStickyElements() {
                     unexpected);
         }
     }
-
-    /**
-     * The framework is expected to take care of the correct scrolling. When you are tempted to scroll from PageObjects
-     * or tests, there is likely a framework problem to be fixed.
-     */
-    public void scrollIntoView(WebElement e) {
-        WebElement element = e;
-        if (Objects.equals(element.getTagName(), "option")) {
-            element = e.findElement(By.xpath("..")); // scroll select into view not option
-        }
-
-        final int eYCoord = element.getLocation().getY();
-        final int eXCoord = element.getLocation().getX();
-        final String id = element.getAttribute("id");
-        final JavascriptExecutor executor = (JavascriptExecutor) driver;
-        // Wait until web element is successfully scrolled.
-        try {
-            new Wait<>(Boolean.TRUE)
-                    .withTimeout(Duration.ofSeconds(5)) // Wall-clock time
-                    .until(() -> (Boolean) executor.executeScript(scrollJs, eYCoord, eXCoord, id));
-        } catch (TimeoutException ex) {
-            // Scrolling failed, but sometimes the element to click is already visible, let the test continue and
-            // eventually fail later
-            // This log message should be sufficient to diagnose the issue
-            LOGGER.log(
-                    Level.WARNING,
-                    "Scrolling failed, letting the test to continue anyways, but \"Element is not clickable\" error will likely be thrown",
-                    ex);
-        }
-    }
 }