feat(Stepper): add allow-empty prop (#6759)

* feat(Stepper): add allow-empty prop

* fix: remove test only

src/stepper/README.md

@@ -129,6 +129,7 @@ export default {
 | show-plus `v2.1.2` | Whether to show plus button | _boolean_ | `true` |
 | show-minus `v2.1.2` | Whether to show minus button | _boolean_ | `true` |
 | long-press `v2.4.3` | Whether to allow long press | _boolean_ | `true` |
+| allow-empty `v2.9.1` | Whether to allow the input to be empty | _boolean_ | `false` |
 
 ### Events
 

src/stepper/README.zh-CN.md

@@ -155,6 +155,7 @@ export default {
 | show-plus `v2.1.2` | 是否显示增加按钮 | _boolean_ | `true` |
 | show-minus `v2.1.2` | 是否显示减少按钮 | _boolean_ | `true` |
 | long-press `v2.4.3` | 是否开启长按手势 | _boolean_ | `true` |
+| allow-empty `v2.9.1` | 是否允许输入的值为空 | _boolean_ | `false` |
 
 ### Events
 

src/stepper/index.js

@@ -28,6 +28,7 @@ export default createComponent({
     theme: String,
     integer: Boolean,
     disabled: Boolean,
+    allowEmpty: Boolean,
     inputWidth: [Number, String],
     buttonSize: [Number, String],
     asyncChange: Boolean,
@@ -154,6 +155,10 @@ export default createComponent({
     },
 
     format(value) {
+      if (this.allowEmpty && value === '') {
+        return value;
+      }
+
       value = this.formatNumber(value);
 
       // format range

src/stepper/test/index.spec.js

@@ -387,3 +387,20 @@ test('placeholder prop', () => {
   });
   expect(wrapper.find('.van-stepper__input')).toMatchSnapshot();
 });
+
+test('allow-empty prop', () => {
+  const wrapper = mount(Stepper, {
+    propsData: {
+      value: '',
+      allowEmpty: true,
+    },
+  });
+
+  const input = wrapper.find('input');
+  input.trigger('blur');
+  expect(wrapper.emitted('input')).toBeFalsy();
+
+  wrapper.setProps({ allowEmpty: false });
+  input.trigger('blur');
+  expect(wrapper.emitted('input')[0][0]).toEqual(1);
+});