Fix position when body scrolled - PR#1 from glenn2223

Applied a fix so the position of the window doesn't affect the position of the anchor position data

Author: glenn2223

src/index.ts

@@ -98,6 +98,13 @@ function position(options: IOptions): PositionData {
 
                 parent = parent.parentElement;
             }
+
+            // Finally, adjust for window scroll position
+            const doc = document.documentElement;
+            _anchorRect.y +=
+                (window.scrollY || doc.scrollTop) - (doc.clientTop || 0);
+            _anchorRect.x +=
+                (window.scrollX || doc.scrollLeft) - (doc.clientLeft || 0);
         }
 
         return {

tests/index.test.ts

@@ -66,3 +66,38 @@ describe('HoverPosition (collisions ignored)', () => {
         });
     });
 });
+
+test('Window scroll adjusts output', () => {
+    window.scrollX = 50;
+    window.scrollY = 50;
+    
+    const tP = 'top left',
+        myA = 'top center',
+        atA = 'bottom center';
+    
+    helper.setupTest(tP);
+
+    const pData = position({
+        ...{ debug: true },
+        ...{
+            my: myA,
+            at: atA,
+            target: document.querySelector<HTMLDivElement>(
+                '.target',
+            )!,
+            anchor: document.querySelector<HTMLElement>('.anchor')!,
+            collision: CollisionHandler.ignore,
+        },
+    }) as allData;
+    
+    expect({
+        left: parseInt(pData.left, 10),
+        top: parseInt(pData.top, 10),
+    }).toStrictEqual({
+        left: helper.getLeft(tP, myA, atA) + 50,
+        top: helper.getTop(tP, myA, atA) + 50,
+    });
+    
+    window.scrollX = 50;
+    window.scrollY = 50;
+});