From ea75a968ce89d77d3ed0a0fc40d4ece40b9e2705 Mon Sep 17 00:00:00 2001
From: KayneWang <w.zengkai@gmail.com>
Date: Sun, 20 Apr 2025 22:11:03 +0900
Subject: [PATCH] fix(Picker): make sure confirm params' behavior consistent
 (#13423) (#13425)

Signed-off-by: Kayne <w.zengkai@gmail.com>
---
 packages/vant/src/picker/Picker.tsx          | 35 ++++++++++----------
 packages/vant/src/picker/test/index.spec.tsx | 32 ++++++++++++++++++
 2 files changed, 49 insertions(+), 18 deletions(-)

diff --git a/packages/vant/src/picker/Picker.tsx b/packages/vant/src/picker/Picker.tsx
index 81ee1b80e..60747676c 100644
--- a/packages/vant/src/picker/Picker.tsx
+++ b/packages/vant/src/picker/Picker.tsx
@@ -147,7 +147,9 @@ export default defineComponent({
     };
 
     const getEventParams = () => ({
-      selectedValues: selectedValues.value.slice(0),
+      selectedValues: selectedValues.value.length
+        ? selectedValues.value.slice(0)
+        : resetSelectedValues(currentColumns.value),
       selectedOptions: selectedOptions.value,
       selectedIndexes: selectedIndexes.value,
     });
@@ -268,23 +270,20 @@ export default defineComponent({
       }
     };
 
-    watch(
-      currentColumns,
-      (columns) => {
-        columns.forEach((options, index) => {
-          if (
-            options.length &&
-            !isOptionExist(options, selectedValues.value[index], fields.value)
-          ) {
-            setValue(
-              index,
-              getFirstEnabledOption(options)![fields.value.value],
-            );
-          }
-        });
-      },
-      { immediate: true },
-    );
+    const resetSelectedValues = (columns: PickerColumn[]) => {
+      columns.forEach((options, index) => {
+        if (
+          options.length &&
+          !isOptionExist(options, selectedValues.value[index], fields.value)
+        ) {
+          setValue(index, getFirstEnabledOption(options)![fields.value.value]);
+        }
+      });
+    };
+
+    watch(currentColumns, (columns) => resetSelectedValues(columns), {
+      immediate: true,
+    });
 
     // preserve last emitted model value
     // when props.modelValue is updated by parent component,
diff --git a/packages/vant/src/picker/test/index.spec.tsx b/packages/vant/src/picker/test/index.spec.tsx
index 29a23ea34..8714c83b7 100644
--- a/packages/vant/src/picker/test/index.spec.tsx
+++ b/packages/vant/src/picker/test/index.spec.tsx
@@ -489,3 +489,35 @@ test('should emit correct values when clicking confirm button during column scro
     },
   ]);
 });
+
+test('should emit default values when clear modelValue', async () => {
+  const columns = [
+    { text: '1', value: '1' },
+    { text: '2', value: '2' },
+  ];
+  const wrapper = mount({
+    setup() {
+      const modelValue = ref(['1']);
+      return () => (
+        <>
+          <button
+            class="clear-button"
+            onClick={() => (modelValue.value = [])}
+          />
+          <Picker v-model={modelValue.value} columns={columns} />
+        </>
+      );
+    },
+  });
+  const button = wrapper.find('.clear-button');
+  await button.trigger('click');
+  const picker = wrapper.findComponent(Picker);
+  await picker.find('.van-picker__confirm').trigger('click');
+  expect(picker.emitted('confirm')![0]).toEqual([
+    {
+      selectedOptions: [{ text: '1', value: '1' }],
+      selectedValues: ['1'],
+      selectedIndexes: [0],
+    },
+  ]);
+});