CODEWITHSUNDEEP
node.jsunit-testingsinon
呂健誠
呂健誠

Reputation: 3

How can i unit test the dependency method

It's my code written in Typescript; I want to test the private getFunc method and the method of redisClient have been called Once. I use supertest to invoke the API, but I can't expect the redis method.

import { Request, Response, Router } from "express";
import * as redis from "redis";
const redisOption: redis.ClientOpts = {
    host: "127.0.0.1",
    port: 6379,
    detect_buffers : true,
    db: 0,
   retry_strategy: () => 60000
}
const redisClient: redis.RedisClient = redis.createClient(redisOption);

export class IndexRoutes {
    public router: Router;
    constructor() {
        this.router = Router();
        this.init();
    }
    public init() {
        this.router.get("/",  this.getFunc);
    }
    private getFunc = async (req: Request, res: Response) => {
        return res.status(200).send(await redisClient.set("test", "123"));
    }
}

error: Uncaught AssertionError: expected get to have been called exactly once, but it was called 0 times

Help me, how do I properly stub the redisClient.get(...) function?

Upvotes: 0

Views: 298

Answers (1)

darth-coder
darth-coder

Reputation: 762

First of all, you don't usually test dependencies/dependency methods. You only test your code.

Secondly, I think you're saying you want want to check if redis.get() is being called or not. That means you'll have to spy on it.

jest.spyOn() is something you should check out.

Your test should look something like:

import * as redis from 'redis';

describe('my redis wrapper', () => {
  it('Should call get when my wrapper\'s getFunc is called', () => {
    let myRedisSpy = jest.spyOn(redis.prototype, 'get');
    // call your function here
    expect(myRedisSpy).toHaveBeenCalledOnce();
  });
});

Or something similar, I don't know if this code will work as is. But, you're always welcome to try.

Upvotes: 1

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