基于AJV的Firebase中间件测试失败问题求助

问题简述 #

开发用于Firebase HTTPS函数的AJV数据验证中间件，需求如下：

• 校验传入数据，合法则调用next继续执行
• 数据非法或Schema加载失败时抛出*HttpsError*

测试场景：加载有效Schema但传入无效数据时，终端能看到AJV的ValidationError，但Jest测试直接崩溃，报错Jest worker encountered 4 child process exceptions, exceeding retry limit。给validate(data)添加try/catch后问题依旧。

测试代码 #

it("should fail with an error when submitting invalid data", () => {
  const middleware = createValidationMiddleware("customer.schema.json");
  expect(() => middleware({})).toThrow(HttpsError);
});

验证脚本（TypeScript） #

export const createValidationMiddleware: (schema: Schemas) => Middleware =
  (schema) => (data, context, next) => {
    const validate = ajv.getSchema(schema);

    if (!validate)
      throw new HttpsError(
        "failed-precondition",
        `schema ${schema} does not exist`
      );

    if (!validate(data))
      throw new HttpsError(
        "invalid-argument",
        `The data is invalid: ${validate.errors}`
      );

    return next(data, context);
  };

错误信息 #

终端AJV验证错误 #

ValidationError: validation failed

Jest测试报错 #

FAIL  src/middlewares/validation.test.ts
  ● Test suite failed to run

    Jest worker encountered 4 child process exceptions, exceeding retry limit

      at ChildProcessWorker.initialize (node_modules/jest-worker/build/workers/ChildProcessWorker.js:170:21)

解决方案 #

• 修复错误信息序列化问题
  validate.errors是AJV的错误对象数组，直接拼接进字符串会导致无法序列化的循环引用，Jest worker进程处理时崩溃。改成JSON序列化错误信息：

  if (!validate(data))
    throw new HttpsError(
      "invalid-argument",
      `The data is invalid: ${JSON.stringify(validate.errors)}`
    );
  

• 补全测试参数
  当前测试调用middleware({})时未传入context和next参数，执行到return next(data, context)时会抛出next is not a function的错误，这是worker崩溃的核心原因之一。修改测试代码，传入mock的next函数：

  it("should fail with an error when submitting invalid data", () => {
    const mockNext = jest.fn();
    const middleware = createValidationMiddleware("customer.schema.json");
    expect(() => middleware({}, {}, mockNext)).toThrow(HttpsError);
  });
  

• 确保HttpsError导入正确
  确认测试文件中正确导入Firebase的HttpsError，避免因模块导入错误导致的异常：

  // 根据Firebase版本选择导入路径
  import { HttpsError } from "firebase-functions/v2/https";
  // 或v1版本：import { HttpsError } from "firebase-functions";
  

• 临时禁用Jest多进程（排查用）
  如果以上方法无效，在jest.config.js中设置单进程测试，排查是否是多进程环境下AJV Schema加载的问题：

  module.exports = {
    // 其他配置项
    maxWorkers: 1
  };
  

内容的提问来源于stack exchange，提问作者Thomas Kuhlmann