fix(hooks): fix usePrevious does not work when passing state

u3u · Aug 7, 2019 · 8567a04 · 8567a04
1 parent c009d5f
commit 8567a04
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Showing 2 changed files with 10 additions and 10 deletions.
diff --git a/src/__tests__/usePrevious.test.ts b/src/__tests__/usePrevious.test.ts
@@ -32,22 +32,22 @@ describe('usePrevious', () => {
 
   it('should be previous state count', () => {
     renderHook(async () => {
-      let count = state(0);
-      const prevCount = usePrevious(() => count);
+      const store = state({ count: 0 });
+      const prevCount = usePrevious(() => store.count);
 
-      expect(count).toBe(0);
+      expect(store.count).toBe(0);
       expect(prevCount.value).toBeUndefined();
 
-      count += 1;
+      store.count += 1;
 
       await Vue.nextTick();
-      expect(count).toBe(1);
+      expect(store.count).toBe(1);
       expect(prevCount.value).toBe(0);
 
-      count -= 1;
+      store.count -= 1;
 
       await Vue.nextTick();
-      expect(count).toBe(0);
+      expect(store.count).toBe(0);
       expect(prevCount.value).toBe(1);
     });
   });

diff --git a/src/usePrevious.ts b/src/usePrevious.ts
@@ -1,9 +1,9 @@
 import { value, watch, Wrapper } from 'vue-function-api';
 
-export default function usePrevious<T>(state: Wrapper<T> | T) {
-  const previous = value<T | undefined>(undefined);
+export default function usePrevious<T>(state: Wrapper<T> | (() => T)) {
+  const previous = value<T>(undefined!);
 
-  watch('value' in state ? state : () => state, (_, oldVal) => {
+  watch(state, (_, oldVal) => {
     previous.value = oldVal;
   });