I have the following event handler and I want to test that updateOrAddNew is being called.
const { Events } = require('client');
const User = require('../models/User');
module.exports = {
name: Events.MemberAdd,
async execute(member) {
User.updateOrAddNew(member);
}
}
I've written the following test:
import {it, expect, vi } from 'vitest';
import User from '../models/User';
import memberAdd from './memberAdd';
it('calls updateOrAddNew on memberAdd', async () => {
const spy = vi.spyOn(User, 'updateOrAddNew').mockReturnValue(true);
User.updateOrAddNew = spy;
const member = {...};
await memberAdd.execute(member);
expect(spy).toBeCalled();
});
I've tried numerous different syntax but the spy is never called. updateOrAddNew is a static method. How can I test whether it's being called when memberAdd.execute is run?
I'm pretty new to testing so any help would be appreciated.
What if you declare in that file globally like this:
jest.spyOn(User, 'updateOrAddNew').mockReturnValue(true);
This should update any usage of this method with mock
Related
I am reading a code like below:
import { MongoMemoryServer } from "mongodb-memory-server";
import mongoose from "mongoose";
import request from "supertest";
import { app } from "../app";
declare global {
function signin(): Promise<string[]>;
}
let mongo: any;
beforeAll(async () => {
process.env.JWT_KEY = "asdfasdf";
process.env.NODE_TLS_REJECT_UNAUTHORIZED = "0";
const mongo = await MongoMemoryServer.create();
const mongoUri = mongo.getUri();
await mongoose.connect(mongoUri, {});
});
beforeEach(async () => {
const collections = await mongoose.connection.db.collections();
for (let collection of collections) {
await collection.deleteMany({});
}
});
afterAll(async () => {
if (mongo) {
await mongo.stop();
}
await mongoose.connection.close();
});
global.signin = async () => {
const email = "test#test.com";
const password = "password";
const response = await request(app)
.post("/api/users/signup")
.send({
email,
password,
})
.expect(201);
const cookie = response.get("Set-Cookie");
return cookie;
};
I can't understand the purpose of global.signin function and how does it work? I guess it has something to do with Jest but as long as I know the Jest codes should be inside the __test__ folder with the same file name and .test.ts extension. But the above function is defined and used inside the setup.ts file in the root of the application.
I also see some codes like following:
declare global {
namespace Express {
interface Request {
currentUser?: UserPayload;
}
}
}
In some .ts files of the project as well that I am not sure are these global variables the same as the other globals I mentioned above or these are different things? I am interested to know how this global variables work as well?
The piece of code you shared is making use of global augmentation https://www.typescriptlang.org/docs/handbook/declaration-merging.html#global-augmentation
// Hint typescript that your global object will have a custom signin function
declare global {
function signin(): Promise<string[]>;
}
// Assign value to global.signin
global.signin = async () => { /* implementation */ };
Likely one or multiple modules ("mongoose", "supertest", "../app") imported by the test file is using global.signin (or window.signin) at some point (or maybe one of their nested imports is => look for "signin(" in the project). Thus for testing purposes, global.signin needed to be mocked. However just adding global.signin = something would raise a typescript error, because signin is not a standard global variable. This is where declare global comes into play. It hints typescript that in your particular context, a signin function is expected to exist in global scope.
JavaScript/TypeScript running in node will try to resolve anything it can't find in the current local scope in global (the same way a browser would look in window). Any function or variable you can access globally (e.g. setTimeout()), can also be accessed with global. as prefix. It just makes it explicit.
What happens in your code are two things:
declare global {
function signin(): Promise<string[]>;
}
Here it tells typescript's type system that the global object also has a function called signin. This part is not required but it makes sense required for typescript to allow you to access / define that function, in JavaScript you simply define it.
https://www.typescriptlang.org/docs/handbook/declaration-merging.html has some details how declare works.
global.signin = async () => {
// code ...
};
And here it is actually added to the global object.
In JavaScript non strict mode you could even write (notice the lack of var/let/const/global.)
signin = async () => {
// code ...
};
I don't see signin getting used anywhere in that code so the reason for it is unclear to me. As long as the file that defines it gets loaded you can call the function simply by referring to it as signin(). The global. is added implicitly.
The purpose of
declare global {
namespace Express {
interface Request {
currentUser?: UserPayload;
}
}
}
is more practical, in express you may want to add properties to your requests that get added by middleware. By declaring that the Express Request has a property called currentUser you get to do
app.get((req, res) => {
const user: UserPayload = req.currentUser
...
})
without typescript complaining about an unknown property.
More on that for example https://blog.logrocket.com/extend-express-request-object-typescript/
Its unclear for me why requireActual (3) is required to use the mock in __mocks__/global.ts (2) instead of global.ts (1) inside app.ts
According to the docs https://jestjs.io/docs/jest-object#jestrequireactualmodulename it says
Returns the actual module instead of a mock, bypassing all checks on
whether the module should receive a mock implementation or not.
What are the mentioned checks?
// __mocks__/global.ts
export const globalConfig = {
configA: "mockedConfigA"
};
export const globalLibA = jest.fn((msg) => {
return msg + "+mockedLibA"
});
// app.ts
import { globalConfig, globalLibA } from "./global"
export const app = function (msg) {
console.log("Called app")
return globalLibA(msg);
}
export const globalConfigConfigA = globalConfig.configA;
Full source: https://github.com/Trenrod/testjest/tree/master/src
I'm writing unit tests with Jest trying to test a module which uses FS.
The module file:
import fs from 'fs';
import logger from './logger.utils';
export const getNumberOfFiles = async (targetDir: string): Promise<number> => {
// get number of folders
logger.info(`getNumberOfFiles from ${targetDir}/${fileName}`);
const numberOfFiles = await fs.readdirSync(targetDir);
return numberOfFiles.length;
};
Test file
import fs from 'fs';
import { getNumberOfFiles } from '../../src/utils/fs.utils';
jest.mock('fs');
describe('fs.utils', () => {
describe('getNumberOfFiles', () => {
it('Should return number', async () => {
fs.readdirSync = jest.fn();
const readdirSyncMock = fs.readdirSync = jest.fn();
readdirSyncMock.mockResolvedValue([1, 2, 3]);
const result = await getNumberOfFiles('targetDir');
expect(result).toEqual(3);
expect(readdirSyncMock.mock.calls.length).toEqual(1);
});
});
});
When I run the test file, I get the following error:
Config file ..../config/runtime.json cannot be read. Error code is: undefined. Error message is: Cannot read property 'replace' of undefined
1 | const cheggLogger = require('#chegg/logger');
2 | import loggingContext from './loggingContext';
> 3 | import config from 'config';
| ^
4 | import os from 'os';
5 | import constants from '../../config/constants';
6 |
at Config.Object.<anonymous>.util.parseFile (node_modules/config/lib/config.js:789:13)
at Config.Object.<anonymous>.util.loadFileConfigs (node_modules/config/lib/config.js:666:26)
at new Config (node_modules/config/lib/config.js:116:27)
at Object.<anonymous> (node_modules/config/lib/config.js:1459:31)
at Object.<anonymous> (src/utils/logger.utils.ts:3:1)
Content of logger.utils.ts
const internalLogger = require('internalLogger');
import loggingContext from './loggingContext';
import config from 'config';
import os from 'os';
import constants from '../../config/constants';
const logger = internalLogger.createLogger({
level: config.get(constants.LOG_LEVEL)
});
export default logger;
I assume that config is using FS, and once I mock the module, it fails.
How can I resolve this? Please advise
I'm guessing the problem comes from config also using the fs api but you are now mock entire module fs which makes all methods should be mocked before using.
But I have an idea for you by using jest.doMock which you can provide a factory for each test and just mock only method we need. Here is a draft idea:
describe('fs.utils', () => {
describe('getNumberOfFiles', () => {
it('Should return number', async () => {
jest.doMock('fs', () => ({
// Keep other methods still working so `config` or others can use
// so make sure we don't break anything
...jest.requireActual('fs'),
readdirSync: jest.fn(pathUrl => {
// Mock for our test path since `config` also uses this method :(
return pathUrl === 'targetDir' ? Promise.resolve([1, 2, 3]) : jest.requireActual('fs').readdirSync(pathUrl)
})
}));
// One of the thing we should change is to switch `require` here
// to make sure the mock is happened before we actually require the code
// we can also use `import` here but requires us do a bit more thing
// so I keep thing simple by using `require`
const {getNumberOfFiles} = require('../../src/utils/fs.utils');
const result = await getNumberOfFiles('targetDir');
expect(result).toEqual(3);
// you might stop assert this as well
// expect(readdirSyncMock.mock.calls.length).toEqual(1);
});
});
});
Just also want to check, if you created a config file as described here: https://www.npmjs.com/package/config#quick-start
I have a very simple code structure like this
TestWorks.ts
const axios = require('axios');
export class TestWorks{
async getUsersList(param1:TestModel, userDetail:any){
console.log("BEGIN -- ... ");
And then this is my test class
MyTest.ts
const testworks = require("../src/interfaces/TestService/TestWorks");
it('Get Users', async () => {
var x = await testworks.getUsersList({}, {});
expect(x).to.be.an("object");
});
but I am seeing the following error, unable to figure out what the issue could be. The paths are definitely right, not an issue with the file paths of where the files are
Get Users:
TypeError: testworks.getUsersList is not a function
at C:\Users\xxxxxx\Documents\xxxxx\test\test-server.test.ts:53:28
testworks refers to the module (or whatever TypeScript exports) because you use require(). You should use import for TypeScript modules.
import { TestWorks } from '../src/interfaces/TestService/TestWorks';
I have a problem. I want to clean my code and put function to another file but I always get an error:
getMe is not a function
why? I want to use it in already exported function getExchangeRateIntent. Is that causing a problem?
outside.js
const getRate = (base) => {
console.log('My base currency is '+base);
};
module.exports = {getRate};
getRate.js
const getMe = ('./outside.js');
module.exports = {
'getExchangeRateIntent': (conv, parameter) => {
const currencyBase = (parameter['currencyBase']);
const currencyTarget = (parameter['currencyTarget']);
const amount = (parameter['amount']);
console.log(currencyBase);
console.log(currencyTarget);
console.log(amount);
getMe('USD');
conv.ask('nothing');
},
};
module.exports = {getRate}; you are exporting an object. With your import:
const getMe = ('./outside.js');
you are importing an object. So this is not a function. This is not a proper import also.
For proper import you could write something like this:
import {getRate} from './outside.js;
And use it like this:
getRate('USD');
Or if you want to use require:
const getMe = require('./outside.js');
And then you can call function like this in second case:
getMe.getRate('USD')