Stubbing pino logger as class instance - node.js

I have a custom log service, using a child instance of pinoLogger to log some things. Here is the code :
class LogService {
ihmLogger = loggerPino.child({});
async log(
req: Request,
level: number,
message: string,
additional?: string
): Promise<void> {
//Context initialisation
const logObj = this.initLogObj(
req,
ngxLoggerLevelToPinoLevel[level],
message,
additional
);
// Mapping log level with pino logger
switch (ngxLoggerLevelToPinoLevel[level]) {
case CONSTANTS.DEFAULT.LOG_NGX_LEVEL.ERROR:
this.ihmLogger.error(logObj);
break;
case CONSTANTS.DEFAULT.LOG_NGX_LEVEL.WARM:
this.ihmLogger.warn(logObj);
break;
case CONSTANTS.DEFAULT.LOG_NGX_LEVEL.INFO:
this.ihmLogger.info(logObj);
break;
case CONSTANTS.DEFAULT.LOG_NGX_LEVEL.DEBUG:
this.ihmLogger.debug(logObj);
break;
}
}
private initLogObj(
req: Request,
level: number,
message: string,
additional?: string
): ILog {
const additionalObj = JSON.parse(additional || '{}');
return {...};
}
}
export default new LogService();
I'm trying to write unit-tests for this service. I'm using node-request-http to mock the Request object, successfully.
My problem concerns this child element. I'm simply trying to see if the correct function is called depending on the level, but I can't access it correctly. Here are the few syntaxes I tried :
[...]
import logService from './log.service';
import { loggerPino } from '../utils/logger';
[...]
it("test 1", async () => {
sinon.stub(loggerPino,'child').returns({
error: sinon.spy()
});
await logService.log(request, 5, 'msg', JSON.stringify({}));
console.log('A',logService.ihmLogger.error);
});
// >> A [Function: noop]
it("test 2", async () => {
const logger = sinon.stub(logService, 'ihmLogger').value({
error: sinon.spy()
});
await logService.log(request, 5, 'msg', JSON.stringify({}));
console.log('B',logger.error);
});
// >> B undefined
it("test 3", async () => {
const logger = sinon.stub(logService, 'ihmLogger').value({
error: sinon.spy()
});
await logService.log(request, 5, 'msg', JSON.stringify({}));
console.log('C',logService.ihmLogger.error);
});
// >> C [Function (anonymous)]
I never could access the "callCount" valut, let alone checking the given parameter with a getCall(0).args[0]
How should I write the stub to be able to correctly access the value i'm trying to test?

The solution here was to completely replace the ihmLogger property of the service, as done in the "B" try up there, but putting it in a variable and checking the variable, not the sinon.stub object returned :
it("Log error called", async () => {
const customLogger = {
trace: sinon.spy(),
debug: sinon.spy(),
info: sinon.spy(),
warn: sinon.spy(),
error: sinon.spy(),
fatal: sinon.spy()
};
sinon.stub(logService, 'ihmLogger').value(customLogger);
await logService.log(request, 5, 'msg', JSON.stringify({}));
expect(customLogger.error.callCount).to.eq(1);
expect(customLogger.fatal.callCount).to.eq(0); //double check to avoid false positive
});
I'm not unit-testing the pinoLogger object (I have to trust if to work as intended), I'm unit-testing the correct branch & call.
Doing this, I'm also able to inspect the logObj transmitted :
const builtObj = customLogger.error.getCall(0).args[0]

Related

Methods called on jest mocked response fails with error

I have the below line in my service.
const timeline = await buildClient.getBuildTimeline(project.id, buildId);
The above code is successfully mocked by jest as below using the __mocks__ approach.
jest.mock('azure-devops-extension-api', () => {
return { getClient: (client: any) => new GitRestClient() };
});
export const mockGetItems = jest
.fn()
.mockReturnValue({ records: [{ state: 2, type: 'TASK', task: { id: TASK_IDS[0] } }] });
class GitRestClient {
public getBuildTimeline(projectId: string, buildId: string): Promise<Timeline[]> {
return new Promise((resolve) => resolve(mockGetItems()));
}
}
But when I get error during jest test in the below find method which acts upon the mocked response.
const record = timeline.records.find((rec) => {
return rec.type === 'Task';
});
How should I update so that the above code snippet is mocked perfectly to return the record value using the find method.

Create IncomingMessage test dummy in Jest

I am trying to write a unit test for a function that takes IncomingMessage as a parameter. I understand it is a stream but I am unsure how to create a basic test dummy as the stream causes my tests to timeout
: Timeout - Async callback was not invoked within the 5000 ms timeout specified by jest.setTimeout.Timeout - Async callback was not invoked within the 5000 ms timeout specified by jest.setTimeout.Error:
My class
import { IncomingMessage } from 'http';
export class MyClass
example(request: IncomingMessage): void {
console.log(request.get('hello?'))
}
}
My test
it('test', () => {
const myclass = new MyClass();
const request = {
get: () => 'hello!'
} as unknown as IncomingMessage
const response = myclass.example(request);
expect(response).toEqual('hello!');
});
I assume I need to close the stream so how can I do that when casting a 'dummy' object to type IncomingMessage?
I tried using
const request = {
get: () => 'hello'
} as unknown as IncomingMessage
request.setTimeout(1)
but then I get an error that the function is not found, which makes sense since the dummy is basically an empty object with only one mocked function
TypeError: request.setTimeout is not a function
In this case I assume I need to actually create a real IncomingMessage? But I cannot find much documentation or examples on how to do this
What is the best way to create a real IncomingMessage stream, close it quickly and have a mocked get method? I think I would then need to mock a socket?
Or what is the correct way to test my class and function in this case?
Basically you need to mock your request object that can be done with below snippet:
function _mock_req() {
let req = {
get: jest.fn(() => 'hello!'),
};
return req;
}
Once mocking is done invoke it in your test case, here I'm using beforeEach that will take care of the issue: openHandler- Async callback was not invoked.
describe('http test', () => {
let req, res;
const myclass = new MyClass();
beforeEach((done) => {
req = _mock_req();
res = myclass.example(req);
done();
});
it('class test', () => {
expect(res).toEqual('hello!');
});
});
You also need to return request from your class to test get passed. While executing test case your mocked request object will get return from MyClass
export class MyClass {
example(request: IncomingMessage): void {
console.log(request.get('hello?'));
return request.get('hello?')
}
}
Test case result:
If you're not using express and using the built in http library for node you can do the following:
Note: This will also work with express too
import httpMocks from 'node-mocks-http';
import handleRequest from '../../../handlers/request';
describe('incoming message mock', () => {
it('working example', () => {
const mockRequest = httpMocks.createRequest({
method: 'POST',
url: '/my-fantastic-endpoint',
headers: {
'content-type': 'application/json',
'accept': 'application/json',
'content-length': '1',
'x-forwarded-for': '127.0.0.1',
},
});
mockRequest.destroy = jest.fn();
const mockResponse = httpMocks.createResponse();
handleRequest(mockRequest, mockResponse);
mockRequest.send({
example: 'hello!',
});
console.log(mockResponse._getData());
expect(true).toBe(true);
});
});

Mock multiple api call inside one function using Moxios

I am writing a test case for my service class. I want to mock multiple calls inside one function as I am making two API calls from one function. I tried following but it is not working
it('should get store info', async done => {
const store: any = DealersAPIFixture.generateStoreInfo();
moxios.wait(() => {
const request = moxios.requests.mostRecent();
request.respondWith({
status: 200,
response: store
});
const nextRequest = moxios.requests.at(1);
nextRequest.respondWith({
status: 200,
response: DealersAPIFixture.generateLocation()
});
});
const params = {
dealerId: store.dealerId,
storeId: store.storeId,
uid: 'h0pw1p20'
};
return DealerServices.retrieveStoreInfo(params).then((data: IStore) => {
const expectedOutput = DealersFixture.generateStoreInfo(data);
expect(data).toMatchObject(expectedOutput);
});
});
const nextRequest is always undefined
it throw error TypeError: Cannot read property 'respondWith' of undefined
here is my service class
static async retrieveStoreInfo(
queryParam: IStoreQueryString
): Promise<IStore> {
const res = await request(getDealerStoreParams(queryParam));
try {
const locationResponse = await graphQlRequest({
query: locationQuery,
variables: { storeId: res.data.storeId }
});
res.data['inventoryLocationCode'] =
locationResponse.data?.location?.inventoryLocationCode;
} catch (e) {
res.data['inventoryLocationCode'] = 'N/A';
}
return res.data;
}
Late for the party, but I had to resolve this same problem just today.
My (not ideal) solution is to use moxios.stubRequest for each request except for the last one. This solution is based on the fact that moxios.stubRequest pushes requests to moxios.requests, so, you'll be able to analyze all requests after responding to the last call.
The code will look something like this (considering you have 3 requests to do):
moxios.stubRequest("get-dealer-store-params", {
status: 200,
response: {
name: "Audi",
location: "Berlin",
}
});
moxios.stubRequest("graph-ql-request", {
status: 204,
});
moxios.wait(() => {
const lastRequest = moxios.requests.mostRecent();
lastRequest.respondWith({
status: 200,
response: {
isEverythingWentFine: true,
},
});
// Here you can analyze any request you want
// Assert getDealerStoreParams's request
const dealerStoreParamsRequest = moxios.requests.first();
expect(dealerStoreParamsRequest.config.headers.Accept).toBe("application/x-www-form-urlencoded");
// Assert graphQlRequest
const graphQlRequest = moxios.requests.get("POST", "graph-ql-request");
...
// Assert last request
expect(lastRequest.config.url).toBe("status");
});

Make partial mock of class with Jest in NodeJS

I'm new to NodeJS and came from PHP, where creating partial mock was easy. But I'm not able to accomplish the same with Jest in NodeJS.
I have a function extractPayloadDates which accept an instance of dialogflow Agent and taking and parsing data from it. I want to mock only single method getParameter of Agent, because no more methods are used in the tested function. I found this code online but it doesn't work
import { Agent } from '../../src/dialogflow/Agent';
import { extractPayloadDates } from '../../src/intents/extractPayloadDates';
describe('extractPayloadDates', () => {
it('tests extracting string', () => {
const AgentMock = jest.fn<Agent, []>(() => ({
getParameter: () => {
return 'some date';
}
}));
const agent = new AgentMock();
expect(extractPayloadDates(agent)).toEqual('some date');
});
});
This code produce following error:
Type '{ getParameter: () => string; }' is missing the following properties from type 'Agent': payload, webhookClient, chatter, getOriginalRequest, and 13 more.ts(2740)
index.d.ts(124, 53): The expected type comes from the return type of this signature.
I also tried to use jest.spyOn, but the problem is, that I cannot create Agent instance as it needs many other objects.
Edit 3.9.2019 with more code
Agent.ts
export class Agent {
private payload: DialogFlowPayload[] = [];
constructor(readonly webhookClient: WebhookClient, private readonly chatter: Chatter) {}
...
}
WebhookClient and Chatter have more dependencies in their constructor as well...
extractPayloads.spec.ts
import { Agent } from '../../src/dialogflow/Agent';
import { extractPayloadDates } from '../../src/intents/extractPayloadDates';
describe('extractPayloadDates', () => {
it('tests extracting string', () => {
const webhookMock = jest.fn();
const chatter = jest.fn();
const agent = new Agent(webhookMock, chatter);
expect(extractPayloadDates(agent)).toEqual('some date');
});
});
This produce another error:
Argument of type 'Mock' is not assignable to parameter of type 'Chatter'.
Property 'getMessage' is missing in type 'Mock' but required in type 'Chatter'
Do I really have to create also WebhookClient and all its dependencies and do the same with Chatter? If I do, I have to create instances of multiple classes just to mock 1 method in Agent, which then will not use any of dependency.
From the docs of jest
If you want to overwrite the original function, you can use jest.spyOn(object, methodName).mockImplementation(() => customImplementation) or object[methodName] = jest.fn(() => customImplementation);
jest.spyOn call jest.fn internally. So you can only mock getParameter method of agent like this:
extractPayloadDates.ts:
function extractPayloadDates(agent) {
return agent.getParameter();
}
export { extractPayloadDates };
Agent.ts:
interface DialogFlowPayload {}
interface WebhookClient {}
interface Chatter {
getMessage(): any;
}
class Agent {
private payload: DialogFlowPayload[] = [];
constructor(readonly webhookClient: WebhookClient, private readonly chatter: Chatter) {}
public getParameter() {
return 'real data';
}
public otherMethod() {
return 'other real data';
}
}
export { Agent, Chatter };
Unit test, only mock getParameter method of agent, keep the original implementation of otherMethod
import { extractPayloadDates } from './extractPayloadDates';
import { Agent, Chatter } from './Agent';
const webhookMock = jest.fn();
const chatter: jest.Mocked<Chatter> = {
getMessage: jest.fn()
};
const agent = new Agent(webhookMock, chatter);
describe('extractPayloadDates', () => {
it('should only mock getParameter method of agent', () => {
agent.getParameter = jest.fn().mockReturnValueOnce('mocked data');
const actualValue = extractPayloadDates(agent);
expect(actualValue).toEqual('mocked data');
expect(agent.otherMethod()).toBe('other real data');
});
});
PASS src/stackoverflow/57428542/extractPayloadDates.spec.ts
extractPayloadDates
✓ should only mock getParameter method of agent (7ms)
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 2.484s, estimated 3s

Dynamically mock dependencies with Jest

I have a method that logs a message via one function in a node environment and via a different function in a browser environment. To check whether I am in a node or browser environment I use the libraries detect-node and is-browser like so:
const isNode = require('detect-node');
const isBrowser = require('is-browser');
log(level, message, data) {
if (isNode) {
this.nodeTransport.log(level, this.name, message, data);
}
if (isBrowser) {
this.browserTransport.log(level, this.name, message, data);
}
}
The variables isNode and isBrowser are set to true and false (automatically via the package) depending on, well, if I'm in a browser or in a node env.
Now I want to test this behavior using jest so I need to mock these npm packages. This is what I tried:
function setup() {
const loggerName = 'Test Logger';
const logger = new Logger(loggerName);
logger.nodeTransport = { log: jest.fn() };
logger.browserTransport = { log: jest.fn() };
logger.splunkTransport = { log: jest.fn() };
return { logger, loggerName };
}
test('it should call the the appropriate transports in a node environment', () => {
const { logger } = setup();
const message = 'message';
jest.mock('detect-node', () => true);
jest.mock('is-browser', () => false);
logger.log('error', message, []);
expect(logger.nodeTransport.log).toHaveBeenCalled();
expect(logger.browserTransport.log).not.toHaveBeenCalled();
});
test('it should call the the appropriate transports in a browser environment', () => {
const { logger } = setup();
const message = 'message';
jest.mock('detect-node', () => false);
jest.mock('is-browser', () => true);
logger.log('error', message, []);
expect(logger.nodeTransport.log).not.toHaveBeenCalled();
expect(logger.browserTransport.log).toHaveBeenCalled();
});
You see, I am using jest.mock to mock detect-node and is-browser and give it different return values. However, this just does not work. The first test is green because (I assume) Jest runs in node, but the second test fails saying
Expected mock function not to be called but it was called with:
["error", "Test Logger", "message", []]
Use .mockClear() to reset the mock calls between tests.
afterEach(() => {
logger.nodeTransport.log.mockClear();
logger.browserTransport.log.mockClear();
});

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