Use intersectionRatio to determine intersection

Some older browsers do not ship with isIntersecting, while they already
have IntersectionObserver support. We make use of `intersectionRatio`
now to fix the Lazy Loader for those browsers.

1 files changed, 3 insertions, 1 deletions

diff --git a/app/assets/javascripts/lazy_loader.js b/app/assets/javascripts/lazy_loader.js
index af50ea9d6c2..ee01a73a6e8 100644
--- a/app/assets/javascripts/lazy_loader.js
+++ b/app/assets/javascripts/lazy_loader.js
@@ -91,7 +91,9 @@ export default class LazyLoader {
 
   onIntersection = entries => {
     entries.forEach(entry => {
-      if (entry.isIntersecting) {
+      // We are using `intersectionRatio > 0` over `isIntersecting`, as some browsers did not ship the latter
+      // See: https://gitlab.com/gitlab-org/gitlab-ce/issues/54407
+      if (entry.intersectionRatio > 0) {
         this.intersectionObserver.unobserve(entry.target);
         this.lazyImages.push(entry.target);
       }