用jest测试类型graphql中间件的正确方法

Question

上下文

我正试图为解析器函数的身份验证中间件编写一个笑话测试。我试图模拟一个实现，以便调用下一个函数，从而通过测试。

错误

我收到的错误是"；next不是函数"；。我可以验证mocked函数是通过expect(isAuth).toHaveBeenCalledTimes(1);调用的，但我的mocked实现显然存在问题。非常感谢您的帮助。

代码

//isAuth Middleware
import { MiddlewareFn } from "type-graphql";
import { Context } from "../utils/interfaces/context";
export const isAuth: MiddlewareFn<Context> = ({ context }, next) => {
const loggedInUserId = context.req.session.id;
if (!loggedInUserId) {
throw new Error("Not authenticated!");
}
return next();
};

//transaction.test.ts
jest.mock("../middleware/isAuth", () => {
return {
isAuth: jest.fn((_, next) => next()), //also tried (next) => next() and (next)=>Promise.resolve(next())
};
});
test("should create a txn successfully", async () => {
//ARRANGE
const user = await createUser(orm);
const txn = createTxnOptions();
const txnToBeCreated = { ...txn, userId: user.id };
//ACT
const response = await testClientMutate(
TXN_QUERIES_AND_MUTATIONS.CREATE_TXN,
{
variables: txnToBeCreated,
}
);
//expect(isAuth).toHaveBeenCalledTimes(1); passes so it's  getting called
console.log(response);
const newlyCreatedTxn: Transaction = (response.data as any)
?.createTransaction;
//ASSERT
const dbTxn = await em.findOne(Transaction, {
id: newlyCreatedTxn.id,
});
expect(newlyCreatedTxn.id).toBe(dbTxn?.id);
});

//transaction.resolver.ts
import { Transaction } from "../entities/Transaction";
import {
Arg,
Ctx,
Mutation,
Query,
Resolver,
UseMiddleware,
} from "type-graphql";
import { Context } from "../utils/interfaces/context";
import { isAuth } from "../middleware/isAuth";
@Mutation(() => Transaction)
@UseMiddleware(isAuth)
async createTransaction(
@Arg("title") title: string,
@Arg("userId") userId: string,
@Ctx() { em }: Context
): Promise<Transaction> {
const transaction = em.create(Transaction, {
title,
user: userId,
});
await em.persistAndFlush(transaction);
return transaction;
}

Answer 1

替换

jest.mock("../middleware/isAuth", () => {
return {
isAuth: jest.fn((_, next) => next()), //also tried (next) => next() and (next)=>Promise.resolve(next())
};
});

与

jest.mock("../middleware/isAuth", () => {
return {
isAuth: (_, next) => next()
};
});