fix(Field): sync input value when dynamically toggling input slot

packages/vant/src/field/Field.tsx

@@ -686,6 +686,17 @@ export default defineComponent({
       },
     );
 
+    // Sync value when input element is recreated (e.g., when toggling custom input slot)
+    // https://github.com/youzan/vant/issues/13769
+    watch(
+      () => inputRef.value,
+      (input) => {
+        if (input && input.value !== getModelValue()) {
+          input.value = getModelValue();
+        }
+      },
+    );
+
     onMounted(() => {
       updateValue(getModelValue(), props.formatTrigger);
       nextTick(adjustTextareaSize);

packages/vant/src/field/test/index.spec.js

@@ -663,3 +663,44 @@ test('should limit maxlength correctly when pasting multiple emojis', async () =
   expect(wrapper.emitted('update:modelValue')[0][0]).toEqual('1😀😀😀');
   expect(input.element.value).toEqual('1😀😀😀');
 });
+
+test('should sync value when dynamically toggling input slot', async () => {
+  const wrapper = mount({
+    data() {
+      return {
+        useSlot: false,
+        modelValue: 'hello',
+      };
+    },
+    render() {
+      return (
+        <Field
+          v-model={this.modelValue}
+          v-slots={{
+            input: this.useSlot ? () => 'Custom Input' : undefined,
+          }}
+        />
+      );
+    },
+  });
+
+  let input = wrapper.find('input');
+  expect(input.element.value).toEqual('hello');
+
+  // Toggle to use custom input slot
+  await wrapper.vm.$data.useSlot = true;
+  await wrapper.vm.$nextTick();
+  expect(wrapper.find('.van-field__control').text()).toContain('Custom Input');
+
+  // Update model value while slot is active
+  await wrapper.vm.$data.modelValue = 'world';
+  await wrapper.vm.$nextTick();
+
+  // Toggle back to native input
+  await wrapper.vm.$data.useSlot = false;
+  await wrapper.vm.$nextTick();
+
+  // The native input should have the updated value
+  input = wrapper.find('input');
+  expect(input.element.value).toEqual('world');
+});

packages/vant/src/slider/Slider.tsx

@@ -129,8 +129,18 @@ export default defineComponent({
       const step = +props.step;
 
       value = clamp(value, min, max);
+
       const diff = Math.round((value - min) / step) * step;
-      return addNumber(min, diff);
+      const steppedValue = addNumber(min, diff);
+
+      if (steppedValue > max) {
+        const prevSteppedValue = addNumber(min, diff - step);
+        const distanceToMax = Math.abs(value - max);
+        const distanceToPrev = Math.abs(value - prevSteppedValue);
+
+        return distanceToMax <= distanceToPrev ? max : prevSteppedValue;
+      }
+      return steppedValue;
     };
 
     const updateStartValue = () => {

packages/vant/src/slider/test/index.spec.ts

@@ -374,3 +374,31 @@ test('should update modelValue correctly after clicking the reversed vertical sl
   trigger(wrapper, 'click', 0, 100);
   expect(wrapper.emitted('update:modelValue')!.pop()).toEqual([0]);
 });
+
+//https://github.com/youzan/vant/issues/13625
+test('should return max when distanceToMax <= distanceToPrev', () => {
+  const wrapper = mount(Slider, {
+    props: { min: 0, max: 50, step: 60, modelValue: 45 },
+  });
+
+  const emitted = wrapper.emitted('update:modelValue');
+  if (emitted && emitted.length > 0) {
+    const result = emitted[emitted.length - 1][0] as number;
+    expect(result).toBe(50); // Should return max
+  }
+});
+
+test('should enter steppedValue > max branch', () => {
+  const wrapper = mount(Slider, {
+    props: { min: 0, max: 12, step: 20, modelValue: 0 },
+  });
+
+  wrapper.setProps({ modelValue: 11 });
+
+  const emitted = wrapper.emitted('update:modelValue');
+  if (emitted && emitted.length > 0) {
+    const result = emitted[emitted.length - 1][0] as number;
+    expect(result).toBeGreaterThanOrEqual(0);
+    expect(result).toBeLessThanOrEqual(12);
+  }
+});