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How to mock a curried function in jest?

I keep running into an issue where one of my curried functions is not a function when mocked out according to jest. I made a set of util httpRequest functions in a file called httpRequest.js that looks like this:
const httpRequest = (method) => {
return (headers) => {
return (data) => {
return async (url) => {
try {
const result = await axios({ method, url, data, headers });
const { data: axiosResult } = result;
return axiosResult;
} catch (err) {
console.log(`${method}Data: `, err);
throw err;
}
};
};
};
};
const getData = httpRequest('get')()();
const postData = httpRequest('post')();
const putData = httpRequest('put')();
const patchData = httpRequest('patch')();
const deleteData = httpRequest('delete')()();
const preBuiltGetRequest = httpRequest('get');
const preBuiltPostRequest = httpRequest('post');
const preBuiltPutRequest = httpRequest('put');
const preBuiltPatchRequest = httpRequest('patch');
const preBuiltDeleteRequest = httpRequest('delete');
module.exports = {
httpRequest,
getData,
postData,
putData,
patchData,
deleteData,
preBuiltGetRequest,
preBuiltPostRequest,
preBuiltPutRequest,
preBuiltPatchRequest,
preBuiltDeleteRequest,
};
When I mock out this file in a test and then use a function such as preBuiltGetRequest I get an error on jest saying TypeError: preBuiltGetRequest(...) is not a function. Here is an example of implementation of this.
Here is the function in my codebase I am testing:
queryUser: async (accessToken, email) => {
const query = `
{
getUsersByCriteria(criteria: Email, values: "${email}") {
id
groups {
id
name
entitlements {
id
code
}
members {
total
}
}
}
}
`;
const newUrl = new URL(`${BaseUrl}/v3/graphql`);
newUrl.searchParams.append('query', papiQuery);
console.log('From the Api ', preBuiltGetRequest);
const getAuthenticatedData = preBuiltGetRequest({
Authorization: `Bearer ${accessToken}`,
})();
const response = await getAuthenticatedData(newUrl.toString());
const graphQlResult = response.data?.getUsersByCriteria;
if (!graphQlResult || graphQlResult.length === 0) {
throw new Error(`Could not find user with email=${email}`);
}
return graphQlResult[0];
},
When I then run the test code mocking out preBuiltGetRequest using this code:
jest.mock('/opt/httpRequest');
const { preBuiltGetRequest } = require('/opt/httpRequest');
I receive this error:

The preBuiltGetRequest function has a signature that can be typed as
declare const prebuiltGetRequest: (header: object) => (data: object) => (url: String) => Promise<never>;
You need to mock it accordingly,
jest.mock('/opt/httpRequest');
const { preBuiltGetRequest } = require('/opt/httpRequest');
const mockSig = jest.fn().mockReturnValue(
jest.fn().mockResolvedValueOnce(error)
)
preBuiltGetRequest.mockReturnValue(mockSig)

Javascript invoke methods from another classes with common parameters

Hello I struggle with the logical organization of code in my project.
I encountered a certain challenge, I have to check database table with some time interval of time if there are any new actions to be performed. Actions can be different and their logic is not related to each other, so I wanted to separate the code of each action into separate files.
I created an example files structure and I think it works the way I would like. I just wonder if it is a good thing that I am passing an instance of the database every time I call a await action.invoke(this.databaseInstance) function repeatedly?
My files:
// index.js
const { Lion } = require('./Lion');
const databaseInstance = {
database: 'Postgress',
dialect: 'SQL'
};
const actionrunner = new Lion({ databaseInstance });
actionrunner.startProcessing();
// Lion.js
const { reoccuringActions } = require('./reoccuringActions');
class Lion {
constructor({ databaseInstance }) {
this.interval = 10000;
this.intervalId = null;
this.databaseInstance = databaseInstance;
}
startProcessing() {
this.recuringInvoke();
this.intervalId = setInterval(this.recuringInvoke.bind(this), this.interval);
}
async recuringInvoke() {
for (const action of reoccuringActions) {
await action.invoke(this.databaseInstance);
}
}
}
module.exports = { Lion };
// reoccuringActions.js
const { BabyLion } = require('./babyLion');
const { BabyCat } = require('./babyCat');
const reoccuringActions = [new BabyLion(), new BabyCat()];
module.exports = { reoccuringActions };
// babyLion.js
class BabyLion {
constructor() {}
async invoke(databaseInstance) {
console.log('invoke BabyLion');
// do something
}
}
module.exports = { BabyLion };
//babyCat.js
class BabyCat {
constructor() {}
async invoke(databaseInstance) {
console.log('invoke babyCat');
// do something
}
}
module.exports = { BabyCat };

Well i don't think there is anything wrong with passing "databaseInstance" every time. But if you want to do in another way you can create "databaseInstance" as variable in each of your action and pass "databaseInstance" in constructor of your action. and use it there, in that way you don't have to pass every time.
// babyLion.js
class BabyLion {
constructor({databaseInstance}) {
this.databaseInstance;
}
async invoke() {
console.log('invoke BabyLion');
// do something
}
}
module.exports = { BabyLion };
//babyCat.js
class BabyCat {
constructor({databaseInstance}) {
this.databaseInstance;
}
async invoke() {
console.log('invoke babyCat');
// do something
}
}
module.exports = { BabyCat };
// reoccuringActions.js
const { BabyLion } = require('./babyLion');
const { BabyCat } = require('./babyCat');
const databaseInstance = require("FromSomewhere");
const reoccuringActions = [
new BabyLion(databaseInstance),
new BabyCat(databaseInstance)
];
module.exports = { reoccuringActions };

Problem stubbing a class method with Sinon

I have a NodeJS + Typescript application with the following class:
export default class OrderStreamWriter {
private readonly redis: IORedis;
private readonly orderStream: string;
private readonly logger: LoggerFactory;
constructor(redisHost: string, redisPort: number, redisPass: string, orderStream: string) {
this.orderStream = orderStream;
this.redis = createRedisClient(redisHost, redisPort, redisPass);
this.logger = new LoggerFactory('streams/OrderStreamWriter');
}
public async write(msg: string): Promise<void> {
await this.redis.xadd(this.orderStream, '*', 'trade', msg).catch((err: Error) => {
this.logger.log(
`Error Writing message to stream (${this.orderStream}): ${err.message}. Quitting...`,
);
process.exit(1);
});
}
}
In another class I use the write method to write the result in a Redis stream.
I want to test that flow without calling the actual write function but just to check that that function will be called with certain parameters, here's my test(run using mocha + sinon):
it('process the input and return an order', () => {
const rule = directOrder[0].rule;
const user = directOrder[0].user;
//const writeStub = sinon.stub(OrderStreamWriter.prototype, "write");
const Writer: any = sinon.stub();
sinon.stub(Writer.prototype, "write");
const writer = new Writer();
const order = {}
// console.log(writeStub)
const directTriggerStrategy: TriggerContext = new TriggerContext(user, rule, writer);
directTriggerStrategy.execute()
sinon.assert.calledWithExactly(writer, order);
})
With both the current code and the commented line const writeStub = sinon.stub(OrderStreamWriter.prototype, "write"); I receive the same error when running the test:
TypeError: Cannot stub non-existent property write
How can I fix this?

// someclass.js
class SomeClass {
prop1;
prop2;
contructor(param1, param2) {
this.prop1 = param1;
this.prop2 = param2;
}
async someFunction(givenParam) {
// do something here
return "somedata";
}
}
// create a factory . This is what you will use to create an instance rather than using the new word ever time to create a new instance.
const someClassInstanceFactory = (param1, param2) => {
return new SomeClass(param1, param2);
};
export default { someClassInstanceFactory, SomeClass };
// ********************************************************
// somemodule.js
// this file uses the class we created above as below
import classAndFactory from "./someclass.js";
const moduleFunction = () => {
const instance = classAndFactory.someClassInstanceFactory(param1, param2);
// this line returns an instance of SomeClass . it's like calling new SomeClass(pram1, param2);
const result = instance.someFunction("givenParam");
console.log(result);
return result;
// result should be 'somedata'
// so how do we unit test moduleFunction and stub instance.someFunction when testing? ?
};
export default moduleFunction;
// *******************************************************************
// somemodule.test.js
import classAndFactory from "./../someclass.js";
import moduleFunction from "./somemodule.js";
const { someClassInstanceFactory, SomeClass } = classAndFactory;
// now if you want to stub any thing what you do is
describe("moduleFunction", () => {
const fakeSomeClassInstance = new SomeClass(1, 2);
// arrange
// stub the factory first to return your fake instance created above.
const expectedResut = "stubbed yoo";
sinon
.stub(classAndFactory, "someClassInstanceFactory")
.returns(fakeSomeClassInstance);
someFunctionStub = sinon
.stub(fakeSomeClassInstance, "someFunction")
.returns(expectedResut);
it("must call someFunction function with required argument", () => {
// act
const result = moduleFunction();
// assert
sinon.assert.calledOnce(someFunctionStub);
assert.equals(result, expectedResut);
});
});

Nodejs Require Class returning {}

So I'm creating a singleton class and when I require it from my server.js file it works fine, but when I require it from another file it returns as undefined. I'll try to post relevant code but some will have to be cut out due to work.
server.js
const express = require('express');
const bodyParser = require('body-parser');
const path = require('path');
const http = require('http');
const app = express();
const config = require('config');
const FBConfigsListener = require('./server/amq_listeners/fb_configs.listener');
const FBConfigs = require('./server/models/FBConfigs');
//Api file for interacting with mongodb
const api = require('./server/routes/api.routes');
//Parsers
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
//Angular Dist output folder
app.use(express.static(path.join(__dirname, 'dist')));
//Api location
app.use('/api', api);
//Send all other requests to angular
app.get('*', (req, res) => {
res.sendFile(path.join(__dirname, 'dist/index.html'));
});
//set port
var port = config.get('webserver.port');
app.set('port', port);
const server = http.createServer(app);
server.listen(port, () => console.log(`Running on localhost:${port}`));
models/FBConfigs.js
var ConfigModel = require('./config');
var config = require('config');
var _ = require('lodash');
var FBConfigsListener = require('../amq_listeners/fb_configs.listener');
var AMQAdapter = require('../adapters/amq.adapter');
var uniqid = require('uniqid');
const connectionOptions = config.get('activemq.connectionOptions');
class FBConfigs {
constructor() {
console.log(config.get('environments'));
this.listener = FBConfigsListener;
this.configs = {};
this.unique_keys = ['id'];
this.update_topic = '/topic/fusebuilder.update.config.';
console.log(FBConfigsListener);
//AMQ Client
this.amq_client = AMQAdapter.getInstance(connectionOptions.host, connectionOptions.port);
}
add(key, config) {
if (!(key in this.configs)) {
this.configs[key] = new ConfigModel(this.unique_keys);
}
this.configs[key].add(config);
}
get(key) {
let configs_json = {};
if (key) {
configs_json[key] = JSON.parse(this.configs[key].toString());
} else {
for (let key in this.configs) {
configs_json[key] = JSON.parse(this.configs[key].toString());
}
}
return configs_json;
}
updateByID(key, id, input_config) {
let configs = this.configs[key].get();
for (let config of configs) {
if (input_config.id === config.id) {
this.update(key, _.merge(config, input_config));
}
}
}
//Send update to config topic
update(key, config) {
let topic = this.update_topic + key;
var update_object = {};
if (Array.isArray(config)) {
update_object[key] = [...config];
} else {
update_object[key] = [config];
}
console.log(`Sending ${key} update:${JSON.stringify(update_object)}`);
this.amq_client.sendMessage(topic, update_object);
}
copyTo(key, id, env) {
let selected_env = config.get('environments.' + env);
// let tmp_amq_client = new AMQAdapter(selected_env.host, selected_env.port);
let selected_config = this.configs[key].getByID(id);
console.log(this);
if (key === 'fuses') {
console.log('In FBConfig Copy to for fuses');
const get_fuse_topic = '/topic/fusebuilder.get_fuse';
const tran_id = uniqid();
const sendObj = { fuseName: id, tran_id };
this.amq_client.sendMessage(get_fuse_topic, sendObj);
var startTime = process.hrtime()[0];
var timeout = false;
while (!this.listener.get_copy_fuse_data(tran_id)) {
console.log('Waiting for config');
sleep(100);
if (process.hrtime()[0] - startTime > 3) {
console.log('Timed out');
timeout = true;
break;
}
}
console.log(JSON.stringify(FBConfigsListener.get_copy_fuse_data(tran_id)));
} else {
tmp_amq_client.sendMessage(this.update_topic, selected_config);
}
console.log(`Copy ${key} id:${id} to ${env}`);
}
}
module.exports = new FBConfigs();
amq_listener/fb_configs.listener.js
const config = require('config');
var AMQAdapter = require('../adapters/amq.adapter');
var FBConfigs = require('../models/FBConfigs');
**removed for work**
class FBConfigsListener {
constructor() {
this.instance;
this.copy_fuse_data = {};
//AMQ Client
this.amq_client = AMQAdapter.getInstance(connectionOptions.host, connectionOptions.port);
//Subscribe to configs
this.amq_client.subscribe(config_subscribe_topic, this.config_topic_callback.bind(this));
//Request Tables
this.amq_client.sendMessage(config_request_topic, { tables: config_tables });
//Subscribe to Copy Fuse topic
this.amq_client.subscribe(subscribe_fuse_copy_topic, this.copy_fuse_callback.bind(this));
}
config_topic_callback(err, message) {
let dest = this.amq_client.getDestination(message);
let key = this.get_key_from_topic(dest);
this.amq_client.readMessage(message, body => {
let configs = JSON.parse(body);
if (key in configs) {
for (let config of configs[key]) {
FBConfigs.add(key, config);
}
}
});
}
copy_fuse_callback(err, message) {
this.amq_client.readMessage(message, body => {
const config = JSON.parse(body);
this.copy_fuse_data[config.tran_id] = config;
});
}
//Get Key from the topic and convert using key map if needed
get_key_from_topic(topic) {
let key = topic.split('.')[topic.split('.').length - 1];
key = key in key_map ? key_map[key] : key;
return key;
}
get_copy_fuse_data(id) {
if (id in this.copy_fuse_data) {
return this.copy_fuse_data[id];
} else {
return false;
}
}
}
module.exports = new FBConfigsListener();
Error happens in FBConfigs. FBConfigsListener returns {} so all functions in there are undefined. Even if I do console.log(require('../amq_listeners/fb_configs.listener')) it prints {} But doing the same thing in server.js (with updated path) it prints the module.
Also tips on how to improve my coding style would be appreciated too.
Edit
So I found out that I have a circular dependency between these classes. How can this be fixed while allowing me to call one from the other.

I would suggest you to instantiate your dependencies firstly and store them in some object which you can pass then to your dependent classes. The structure can be
factories/services.js
/*
* Instantiates passed services and passes injector object to them
*/
module.exports = function createServices(injector, services) {
return Object.entries(services)
.reduce((aggregator, [name, serv]) => {
const name_ = camelCase(name);
aggregator.set(name_, new serv(injector));
return aggregator;
}, new Map());
};
lib/service.js
/**
* Base class for classes need any injections
*/
module.exports = class Service {
constructor(injector) {
this.injector = injector;
}
get dependencies() {
return this.injector.dependencies;
}
/*
* Background jobs can be ran here
*/
async startService() {}
/*
* Background jobs can be stopped here
*/
async stopService() {}
};
lib/injector.js
const Service = require('./service');
/*
* Contains all dependencies
*/
module.exports = class Injector {
constructor() {
this.services = new Map();
this._dependencies = {};
}
has(name) {
return this.services.has(name);
}
register(name, service) {
if (this.has(name)) {
throw new Error(`Service ${name} already exists`);
}
if (service instanceof Service === false) {
throw new Error('Argument #2 should be an instance of Service');
}
this.services.set(name, service);
this._dependencies[name] = service;
}
unregister(name) {
if (! this.has(name)) {
throw new Error(`Service ${name} not found`);
}
this.services.delete(name);
delete this._dependencies[name];
}
get dependencies() {
return { ...this._dependencies };
}
/*
* Starts all registered services
*/
async start() {
for (let service of this.services.values()) {
await service.startService();
}
}
/*
* Stops all registered services
*/
async stop() {
for (let service of this.services.values()) {
await service.stopService();
}
}
};
Then import, initialize and bind your services in the main file (don't forget to export just a class, not an object like you do it now).
server.js
const createServices = require('./factories/services.js');
const injector = require('./lib/injector');
const Injector = new injector();
const services = createServices(Injector, [require('./server/amq_listeners/fb_configs.listener'), require('./server/models/FBConfigs')]);
services.forEach((service, name) => {
Injector.register(name, service);
});
// Start services
Injector.start();
Inherit required classes to Service class and you will get an access to all dependencies there (don't forget to call super() from constructor). Like
models/FBConfigs.js
const Service = require('../lib/service');
class FBConfigs extends Service {
constructor(injector) {
super(injector);
const { FBConfigsListener } = this.dependencies;
...your code here
}
async startService() {
...run bg job or init some connection
}
async stopService() {
...stop bg job or close some connection
}
}
module.exports = FBConfigs;
Also you can pass some config object to createServices (I didn't include it here) with keys equal to service names and values containing config object and pass config to appropriate service.

It is caused by that circular dependency. You should avoid it or used very carefully.
In your case the fix is probably pretty simple, move the line var FBConfigs = require('../models/FBConfigs'); from listener at the end of the file as the last line (yes, even after the module.exports).
Edit: Actually it maybe is not enough as I checked the code more in detail. As you are not using Listener in FBConfig constructor, you can create method assignListener, remove this.listener from that constructor and call it later in server.js which will do the this.listener
Or the last solution, which is also "best practice". Do not export the instances. Export the classes only. Then in server.js create these instances after both are required.

Test plain javascript file returning different objects

Is it possible to test the code below with Jasmine testing tool or any other npm module like rewire or similar?
const AuthValidatorDumb = require('./src/AuthValidatorDumb');
const AuthValidator = require('./src/AuthValidator');
const config = require('../config');
let instance;
if (!instance) {
if (config.get('auth.enabled')) {
instance = AuthValidator;
} else {
instance = AuthValidatorDumb;
}
}
module.exports = instance;

I've got a variant for testing the code above.Suppose you have:
1) The code for index.js in the question above.
2) AuthValidator.js:
class AuthValidator {}
module.exports = AuthValidator;
3) AuthValidatorDumb.js:
class AuthValidatorDumb {}
module.exports = AuthValidatorDumb;
Here is test/index.spec.js:
const proxyquire = require('proxyquire');
const AuthValidator = require('../src/AuthValidator');
const AuthValidatorDumb = require('../src/AuthValidatorDumb');
describe('auth index', () => {
it('should return AuthValidator', () => {
const configMock = { get: () => 'sth' };
const Instance = proxyquire('../index', {
'../config': configMock,
});
expect(new Instance() instanceof AuthValidator).toBeTruthy();
});
it('should return AuthValidatorDumb', () => {
const configMock = { get: () => undefined };
const Instance = proxyquire('../index', {
'../config': configMock,
});
expect(new Instance() instanceof AuthValidatorDumb).toBeTruthy();
});
});