Fix/issue 31 fullpage scroll

lib/clientSideScripts/hideScrollbars.ts

@@ -1,10 +1,18 @@
 /**
  * Hide the scrollbars
+ *
+ * There is a `try/catch` for this issue
+ * https://github.com/wswebcreation/webdriver-image-comparison/issues/30
+ * Some browsers don't wrap XML into a body element, so this will fail
  */
 export default function hideScrollBars(hide: boolean): void {
-  if (hide) {
-    document.body.style.overflow = 'hidden';
-  } else {
-    document.body.style.overflow = '';
+  try {
+    if (hide) {
+      document.body.style.overflow = 'hidden';
+    } else {
+      document.body.style.overflow = '';
+    }
+  } catch (e) {
+    // Do nothing
   }
 }

lib/clientSideScripts/scrollToPosition.ts

@@ -1,57 +1,8 @@
 /**
- * Scroll to a x = 0 and y = variable position in the screen
- * Sometimes a scroll can't be done on the window, so the scroll needs to be done on the largest
- * element on the screen
+ * Scroll to y = variable position in the screen
  */
+/* istanbul ignore next */
 export default function scrollToPosition(yPosition: number): void {
-  const initialScroll = document.documentElement.scrollTop;
-
-  // If for some reason the scroll didn't work, find the first largest element and use that to scroll on
-  let largestNode: HTMLElement;
-
   // Scroll with the default way of scrolling
-  window.scrollTo(0, yPosition);
-
-  /* istanbul ignore else */
-  if (initialScroll === document.documentElement.scrollTop && yPosition > 0) {
-    largestFirstNode(document.documentElement.childNodes).scrollTo(0, yPosition);
-  }
-
-  /**
-   * Find the first largest node in the page so it  can be used for scrolling
-   */
-  function largestFirstNode(nodesList: any) {
-    let node: HTMLElement;
-
-    // Loop over the nodes
-    for (let i = nodesList.length - 1; i >= 0; i--) {
-      node = nodesList[i];
-
-      // Stop if the largest node has been found
-      /* istanbul ignore next */
-      if (largestNode) {
-        break;
-      }
-
-      // Check if the element has a scroll / client height
-      /* istanbul ignore next */
-      if (node.scrollHeight && node.clientHeight) {
-        const viewPortHeight = Math.max(document.documentElement.clientHeight, window.innerHeight || 0);
-        const elHeight = Math.max(node.scrollHeight, node.clientHeight);
-
-        // If the element is bigger than the viewport, then we got our scroll container
-        if (elHeight > viewPortHeight) {
-          largestNode = node;
-          break;
-        }
-      }
-
-      if (node.childNodes.length) {
-        largestFirstNode(node.childNodes);
-      }
-    }
-
-    // If the largestNode is the body then return the window
-    return (document.body === largestNode || !largestNode) ? window : largestNode;
-  }
+  (document.scrollingElement || document.documentElement).scrollTop  = yPosition;
 }