[new feature] Stepper: add input-width prop (#3076)

packages/stepper/test/__snapshots__/index.spec.js.snap

@@ -3,3 +3,5 @@
 exports[`disable stepper input 1`] = `<div class="van-stepper"><button class="van-stepper__minus van-stepper__minus--disabled"></button><input type="number" disabled="disabled" class="van-stepper__input"><button class="van-stepper__plus"></button></div>`;
 
 exports[`disabled stepper 1`] = `<div class="van-stepper"><button class="van-stepper__minus van-stepper__minus--disabled"></button><input type="number" disabled="disabled" class="van-stepper__input"><button class="van-stepper__plus van-stepper__plus--disabled"></button></div>`;
+
+exports[`input width 1`] = `<div class="van-stepper"><button class="van-stepper__minus van-stepper__minus--disabled"></button><input type="number" class="van-stepper__input" style="width: 10rem;"><button class="van-stepper__plus"></button></div>`;

packages/stepper/test/index.spec.js

@@ -108,3 +108,12 @@ test('stepper blur', () => {
   expect(wrapper.emitted('input')).toEqual([[0], [3]]);
   expect(wrapper.emitted('blur')).toBeTruthy();
 });
+
+test('input width', () => {
+  const wrapper = mount(Stepper, {
+    propsData: {
+      inputWidth: '10rem'
+    }
+  });
+  expect(wrapper).toMatchSnapshot();
+});