[Bug]: dont do anything if already have match

README.md

@@ -10,7 +10,7 @@ Why use an administrator to manage all the elements on my page?
 ------------------------------------------------------------------------------
 This library is used in [ember-in-viewport](https://github.com/DockYard/ember-in-viewport) and [ember-infinity](https://github.com/ember-infinity/ember-infinity).  This library is particularly important for re-using the IntersectionObserver API.
 
-Most implementations have one Intersection Observer for each target element or so called `sentinel`.  However, [IntersectionObserver.observe](https://developer.mozilla.org/en-US/docs/Web/API/IntersectionObserver/observe) can observer multiple `sentinels`.  So this library will resuse the IntersectionObserver instance for another element on the page with the same set of observer options and root element.  This can dramatically improve performance for pages with lots of elements and observers.
+Most implementations have one Intersection Observer for each target element or so called `sentinel`.  However, [IntersectionObserver.observe](https://developer.mozilla.org/en-US/docs/Web/API/IntersectionObserver/observe) can observer multiple `sentinels`.  So this library will reuse the IntersectionObserver instance for another element on the page with the same set of observer options and root element.  This can dramatically improve performance for pages with lots of elements and observers.
 
 _Note: A companion library is also available for requestAnimationFrame: https://github.com/snewcomer/raf-pool_
 

src/index.ts

@@ -159,8 +159,10 @@ export default class IntersectionObserverAdmin extends Notifications {
       if (intersectionObserver) {
         intersectionObserver.observe(element);
       }
-    } else {
+    } else if (!potentialRootMatch) {
       // otherwise start observing this element if applicable
+      // and add entry to WeakMap under a root element
+      // with watcher so we can use it later on
       // watcher is an instance that has an observe method
       const intersectionObserver = this.newObserver(element, options);
 
@@ -170,19 +172,12 @@ export default class IntersectionObserverAdmin extends Notifications {
         options
       };
 
-      // and add entry to WeakMap under a root element
-      // with watcher so we can use it later on
       const stringifiedOptions: string = this.stringifyOptions(options);
-      if (potentialRootMatch) {
-        // if share same root and need to add new entry to root match
-        // not functional but :shrug
-        potentialRootMatch[stringifiedOptions] = observerEntry;
-      } else {
-        // no root exists, so add to WeakMap
-        this.elementRegistry.addElement(root, {
-          [stringifiedOptions]: observerEntry
-        });
-      }
+
+      // no root exists, so add to WeakMap
+      this.elementRegistry.addElement(root, {
+        [stringifiedOptions]: observerEntry
+      });
     }
   }