feat(usePreviousDistinct): improve types;

streamich · Nov 4, 2019 · 30f53e8 · 30f53e8
1 parent d4ff80a
commit 30f53e8
Showing 1 changed file with 5 additions and 7 deletions.
diff --git a/src/usePreviousDistinct.ts b/src/usePreviousDistinct.ts
@@ -1,15 +1,13 @@
 import { useRef } from 'react';
 
-function strictEquals<T>(prev: T | undefined, next: T) {
-  return prev === next;
-}
+export type Predicate<T> = (prev: T | undefined, next: T) => boolean;
+
+const strictEquals = <T>(prev: T | undefined, next: T) => prev === next;
 
-export default function usePreviousDistinct<T>(
-  value: T,
-  compare: (prev: T | undefined, next: T) => boolean = strictEquals
-) {
+export default function usePreviousDistinct<T>(value: T, compare: Predicate<T> = strictEquals): T | undefined {
   const prevRef = useRef<T>();
   const curRef = useRef<T>();
+
   if (!compare(curRef.current, value)) {
     prevRef.current = curRef.current;
     curRef.current = value;