From 044f0afc1eb5535e16dacb4b694a05101c52c080 Mon Sep 17 00:00:00 2001
From: qiang <qw13131wang@gmail.com>
Date: Thu, 29 Aug 2024 19:06:41 +0800
Subject: [PATCH] fix(components): [select] switching single/multiple generates
 an error (#18030)

closed #17890
---
 .../components/select/__tests__/select.test.ts | 10 ++++++++++
 packages/components/select/src/useSelect.ts    | 18 ++++++------------
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/packages/components/select/__tests__/select.test.ts b/packages/components/select/__tests__/select.test.ts
index bc32a82ef9..b62545e778 100644
--- a/packages/components/select/__tests__/select.test.ts
+++ b/packages/components/select/__tests__/select.test.ts
@@ -2741,4 +2741,14 @@ describe('Select', () => {
     await wrapper.find(`.${WRAPPER_CLASS_NAME}`).trigger('click')
     expect(handleClick).toHaveBeenCalledOnce()
   })
+
+  test('should be run normally when switching multiple', async () => {
+    wrapper = getSelectVm({ multiple: false })
+    const vm = wrapper.vm as any
+
+    await (vm.value = undefined)
+    await (vm.multiple = true)
+    await (vm.multiple = false)
+    expect(vm.value).toBe(undefined)
+  })
 })
diff --git a/packages/components/select/src/useSelect.ts b/packages/components/select/src/useSelect.ts
index 6183f27500..c34ec40f07 100644
--- a/packages/components/select/src/useSelect.ts
+++ b/packages/components/select/src/useSelect.ts
@@ -66,7 +66,7 @@ export const useSelect = (props: ISelectProps, emit) => {
     cachedOptions: new Map(),
     disabledOptions: new Map(),
     optionValues: [] as any[], // sorted value of options
-    selected: props.multiple ? [] : ({} as any),
+    selected: [] as any[],
     selectionWidth: 0,
     calculatorWidth: 0,
     collapseItemWidth: 0,
@@ -406,7 +406,7 @@ export const useSelect = (props: ISelectProps, emit) => {
         : props.modelValue
       const option = getOption(value)
       states.selectedLabel = option.currentLabel
-      states.selected = option
+      states.selected = [option]
       return
     } else {
       states.selectedLabel = ''
@@ -456,17 +456,11 @@ export const useSelect = (props: ISelectProps, emit) => {
   }
 
   const updateHoveringIndex = () => {
-    if (!props.multiple) {
-      states.hoveringIndex = optionsArray.value.findIndex((item) => {
-        return getValueKey(item) === getValueKey(states.selected)
-      })
-    } else {
-      states.hoveringIndex = optionsArray.value.findIndex((item) =>
-        states.selected.some(
-          (selected) => getValueKey(selected) === getValueKey(item)
-        )
+    states.hoveringIndex = optionsArray.value.findIndex((item) =>
+      states.selected.some(
+        (selected) => getValueKey(selected) === getValueKey(item)
       )
-    }
+    )
   }
 
   const resetSelectionWidth = () => {