feat(Form): rule message can be function (#5704)

src/form/README.md

@@ -437,8 +437,8 @@ export default {
 
 | Key | Description | Type |
 |------|------|------|
-| message | Error message | *string* |
 | required | Whether to be a required field | *boolean* |
+| message `v2.5.3` | Error message | *string \| (value, rule) => string* |
 | validator `v2.5.3` | Custom validator | *(value, rule) => boolean \| Promise* |
 | pattern `v2.5.3` | Regex pattern | *RegExp* |
 | trigger `v2.5.2` | When to validate the form，can be set to `onChange`、`onBlur` | *string* |

src/form/README.zh-CN.md

@@ -476,8 +476,8 @@ export default {
 
 | 键名 | 说明 | 类型 |
 |------|------|------|
-| message | 错误提示文案 | *string* |
 | required | 是否为必选字段 | *boolean* |
+| message `v2.5.3` | 错误提示文案 | *string \| (value, rule) => string* |
 | validator `v2.5.3` | 通过函数进行校验 | *(value, rule) => boolean \| Promise* |
 | pattern `v2.5.3` | 通过正则表达式进行校验 | *RegExp* |
 | trigger `v2.5.2` | 本项规则的触发时机，可选值为`onChange`、`onBlur` | *string* |

src/form/test/props.spec.js

@@ -59,6 +59,33 @@ test('rules prop - pattern', async () => {
   });
 });
 
+test('rules prop - message function', async () => {
+  const onFailed = jest.fn();
+  const wrapper = mountForm({
+    template: `
+      <van-form @failed="onFailed">
+        <van-field name="A" :rules="rules" value="123" />
+        <van-button native-type="submit" />
+      </van-form>
+    `,
+    data() {
+      return {
+        rules: [{ pattern: /\d{6}/, message: val => val }],
+      };
+    },
+    methods: {
+      onFailed,
+    },
+  });
+
+  await submitForm(wrapper);
+
+  expect(onFailed).toHaveBeenCalledWith({
+    errors: [{ message: '123', name: 'A' }],
+    values: { A: '123' },
+  });
+});
+
 test('rules prop - formatter', async () => {
   const onFailed = jest.fn();
   const wrapper = mountForm({