fix(Field): fix the length of emoji (#10033)

packages/vant/src/field/Field.tsx

@@ -27,12 +27,14 @@ import {
   createNamespace,
 } from '../utils';
 import {
+  cutString,
   runSyncRule,
   endComposing,
   mapInputType,
   startComposing,
   getRuleMessage,
   resizeTextarea,
+  getStringLength,
   runRuleValidator,
 } from './utils';
 import { cellSharedProps } from '../cell/Cell';
@@ -255,12 +257,12 @@ export default defineComponent({
     // see: https://github.com/youzan/vant/issues/5033
     const limitValueLength = (value: string) => {
       const { maxlength } = props;
-      if (isDef(maxlength) && value.length > maxlength) {
+      if (isDef(maxlength) && getStringLength(value) > maxlength) {
         const modelValue = getModelValue();
-        if (modelValue && modelValue.length === +maxlength) {
+        if (modelValue && getStringLength(modelValue) === +maxlength) {
           return modelValue;
         }
-        return value.slice(0, +maxlength);
+        return cutString(value, +maxlength);
       }
       return value;
     };
@@ -462,7 +464,7 @@ export default defineComponent({
 
     const renderWordLimit = () => {
       if (props.showWordLimit && props.maxlength) {
-        const count = getModelValue().length;
+        const count = getStringLength(getModelValue());
         return (
           <div class={bem('word-limit')}>
             <span class={bem('word-num')}>{count}</span>/{props.maxlength}

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

@@ -62,21 +62,11 @@ exports[`should render textarea when type is textarea 1`] = `
 `;
 
 exports[`should render word limit correctly 1`] = `
-<div class="van-cell van-field">
-  <div class="van-cell__value van-cell__value--alone van-field__value">
-    <div class="van-field__body">
-      <input type="text"
-             id="van-field-input"
-             class="van-field__control"
-      >
-    </div>
-    <div class="van-field__word-limit">
-      <span class="van-field__word-num">
-        3
-      </span>
-      /3
-    </div>
-  </div>
+<div class="van-field__word-limit">
+  <span class="van-field__word-num">
+    3
+  </span>
+  /3
 </div>
 `;
 
@@ -117,3 +107,12 @@ exports[`should render word limit correctly when modelValue is undefined 1`] = `
   </div>
 </div>
 `;
+
+exports[`should render word limit with emoji correctly 1`] = `
+<div class="van-field__word-limit">
+  <span class="van-field__word-num">
+    2
+  </span>
+  /3
+</div>
+`;

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

@@ -343,7 +343,7 @@ test('should render word limit correctly', () => {
       showWordLimit: true,
     },
   });
-  expect(wrapper.html()).toMatchSnapshot();
+  expect(wrapper.find('.van-field__word-limit').html()).toMatchSnapshot();
 });
 
 test('should render word limit correctly when modelValue is undefined', () => {
@@ -475,3 +475,26 @@ test('should render error-message slot correctly', async () => {
 
   expect(wrapper.find('.van-field__error-message').html()).toMatchSnapshot();
 });
+
+test('should limit maxlength with emoji correctly', async () => {
+  const wrapper = mount(Field, {
+    props: {
+      maxlength: 3,
+      modelValue: '😀😀😀😀',
+    },
+  });
+
+  const input = wrapper.find('input');
+  expect(input.element.value).toEqual('😀😀😀');
+});
+
+test('should render word limit with emoji correctly', () => {
+  const wrapper = mount(Field, {
+    props: {
+      modelValue: '😀😀',
+      maxlength: 3,
+      showWordLimit: true,
+    },
+  });
+  expect(wrapper.find('.van-field__word-limit').html()).toMatchSnapshot();
+});

packages/vant/src/field/utils.ts

@@ -107,3 +107,14 @@ export function mapInputType(type: FieldType): {
 
   return { type };
 }
+
+// get correct length of emoji
+// https://github.com/youzan/vant/issues/10032
+export function getStringLength(str: string) {
+  return [...str].length;
+}
+
+// cut string with emoji
+export function cutString(str: string, maxlength: number) {
+  return [...str].slice(0, maxlength).join('');
+}