Prevent intersectionRatio from being higher than 1 in IntersectionObserverEntry (#41448)

rubennorte · facebook-github-bot · commit 5948ab751575 · 2023-11-14T06:11:13.000-08:00
Summary: Pull Request resolved: #41448 This was possible before due to precision problems with `double` (we were seeing values like 1.000000002). This is an easy way to prevent that problem. Changelog: [internal] Reviewed By: rshest Differential Revision: D51230183 fbshipit-source-id: 757ef181fe369d525831faf8a6d907467efc544c
diff --git a/packages/react-native/Libraries/IntersectionObserver/IntersectionObserverEntry.js b/packages/react-native/Libraries/IntersectionObserver/IntersectionObserverEntry.js
@@ -66,10 +66,12 @@ export default class IntersectionObserverEntry {
       return 0;
     }
 
-    return (
+    const ratio =
       (intersectionRect.width * intersectionRect.height) /
-      (boundingClientRect.width * boundingClientRect.height)
-    );
+      (boundingClientRect.width * boundingClientRect.height);
+
+    // Prevent rounding errors from making this value greater than 1.
+    return Math.min(ratio, 1);
   }
 
   /**

Original file line number	Diff line number	Diff line change
`@@ -66,10 +66,12 @@ export default class IntersectionObserverEntry {`
`66`	`66`	`return 0;`
`67`	`67`	`}`
`68`	`68`
`69`		`- return (`
	`69`	`+ const ratio =`
`70`	`70`	`(intersectionRect.width * intersectionRect.height) /`
`71`		`- (boundingClientRect.width * boundingClientRect.height)`
`72`		`- );`
	`71`	`+ (boundingClientRect.width * boundingClientRect.height);`
	`72`	`+`
	`73`	`+ // Prevent rounding errors from making this value greater than 1.`
	`74`	`+ return Math.min(ratio, 1);`
`73`	`75`	`}`
`74`	`76`
`75`	`77`	`/**`