JSONSchema -必需的属性不起作用

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "properties": {
    "name": {
      "type": "string"
    },
    "age": {
      "type": "integer"
    }
  },
  "required": ["name"]
}

{
  "age": 30
}

const Ajv = require('ajv');
const ajv = new Ajv();

const schema = {
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "properties": {
    "name": {
      "type": "string"
    },
    "age": {
      "type": "integer"
    }
  },
  "required": ["name"]
};

const data = {
  "age": 30
};

const validate = ajv.compile(schema);
const valid = validate(data);

if (!valid) {
  console.log(validate.errors);
} else {
  console.log('Data is valid');
}