fix(useArrayReduce): initialValue can be a function (#4243)

Mutter45 · antfu · web-flow · commit ae542c6b62b2 · 2024-10-24T16:46:46.000Z
Co-authored-by: Anthony Fu &lt;anthonyfu117@hotmail.com&gt;
diff --git a/packages/shared/useArrayReduce/index.test.ts b/packages/shared/useArrayReduce/index.test.ts
@@ -37,4 +37,15 @@ describe('useArrayReduce', () => {
     list.push({ num: 3 })
     expect(sum.value).toBe(6)
   })
+  it.skipIf(isVue2)('should work with initialValue being a function', () => {
+    const list = reactive([{ num: 1 }, { num: 2 }])
+    const sum = useArrayReduce(list, (prev, val) => {
+      prev.push(val.num)
+      return prev
+    }, (() => []) as unknown as number[])
+    expect(sum.value).toEqual([1, 2])
+
+    list.push({ num: 3 })
+    expect(sum.value).toEqual([1, 2, 3])
+  })
 })
diff --git a/packages/shared/useArrayReduce/index.ts b/packages/shared/useArrayReduce/index.ts
@@ -57,7 +57,7 @@ export function useArrayReduce<T>(
     // Depending on the behavior of reduce, undefined is also a valid initialization value,
     // and this code will distinguish the behavior between them.
     return args.length
-      ? resolved.reduce(reduceCallback, toValue(args[0]))
+      ? resolved.reduce(reduceCallback, typeof args[0] === 'function' ? toValue(args[0]()) : toValue(args[0]))
       : resolved.reduce(reduceCallback)
   })
 }

Original file line number	Diff line number	Diff line change
`@@ -57,7 +57,7 @@ export function useArrayReduce<T>(`
`57`	`57`	`// Depending on the behavior of reduce, undefined is also a valid initialization value,`
`58`	`58`	`// and this code will distinguish the behavior between them.`
`59`	`59`	`return args.length`
`60`		`- ? resolved.reduce(reduceCallback, toValue(args[0]))`
	`60`	`+ ? resolved.reduce(reduceCallback, typeof args[0] === 'function' ? toValue(args[0]()) : toValue(args[0]))`
`61`	`61`	`: resolved.reduce(reduceCallback)`
`62`	`62`	`})`
`63`	`63`	`}`