如何禁止json架构数组中某些anyOf项多次出现

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

// 定义 JSON Schema
const schema = {
  type: 'array',
  items: {
    anyOf: [
      { type: 'string', pattern: '^item1$' },
      { type: 'string', pattern: '^item2$' },
      { type: 'string', pattern: '^item3$' }
    ]
  }
};

// 自定义验证函数
function validateUniqueAnyOf(items) {
  const counts = {};
  items.forEach(item => {
    const matchedSchema = schema.items.anyOf.find(schemaItem => ajv.validate(schemaItem, item));
    if (matchedSchema) {
      const key = JSON.stringify(matchedSchema);
      counts[key] = (counts[key] || 0) + 1;
      if (counts[key] > 1) {
        throw new Error(`Duplicate anyOf item found: ${JSON.stringify(item)}`);
      }
    }
  });
}

// 测试数据
const validData = ['item1', 'item2'];
const invalidData = ['item1', 'item1'];

try {
  validateUniqueAnyOf(validData); // 不会抛出错误
  console.log('Valid data passed');
} catch (e) {
  console.error(e.message);
}

try {
  validateUniqueAnyOf(invalidData); // 抛出错误
  console.log('Invalid data passed');
} catch (e) {
  console.error(e.message);
}