Add bottomVisible

snippets/bottom-visible.md

@@ -0,0 +1,16 @@
+### Bottom visible
+
+Returns `true` if bottom of the page is visible. It adds `scrollY` to
+the height of the visible portion of the page (`clientHeight`) and
+compares it to `pageHeight` to see if bottom of the page is visible.
+
+```js
+const bottomVisible = () => {
+  const scrollY = window.scrollY;
+  const visibleHeight = document.documentElement.clientHeight;
+  const pageHeight = document.documentElement.scrollHeight;
+  const bottomOfPage = visibleHeight + scrollY >= pageHeight;
+
+  return bottomOfPage || pageHeight < visibleHeight;
+}
+```