feat(Field): highlight word num when reaching maxlength

src/field/test/__snapshots__/index.spec.js.snap

@@ -53,6 +53,15 @@ exports[`label-width prop without unit 1`] = `
 </div>
 `;
 
+exports[`reach max word-limit 1`] = `
+<div class="van-cell van-field">
+  <div class="van-cell__value van-cell__value--alone">
+    <div class="van-field__body"><input type="text" class="van-field__control"></div>
+    <div class="van-field__word-limit"><span class="van-field__word-num van-field__word-num--full">3</span>/3</div>
+  </div>
+</div>
+`;
+
 exports[`render input slot 1`] = `
 <div class="van-cell van-field">
   <div class="van-cell__value van-cell__value--alone">

src/field/test/index.spec.js

@@ -280,3 +280,14 @@ test('formatter prop', () => {
   input.trigger('input');
   expect(wrapper.emitted('input')[1][0]).toEqual('efg');
 });
+
+test('reach max word-limit', () => {
+  const wrapper = mount(Field, {
+    propsData: {
+      value: 'foo',
+      maxlength: 3,
+      showWordLimit: true,
+    },
+  });
+  expect(wrapper).toMatchSnapshot();
+});