How to test node.js-mongodb app using Mocha, Chai and Sinon? I am having difficulty with Sinon part - mongodb

Question

I am new to testing and having difficulty with Sinon stubs and mocks.
How can I write test for 'quote.list_quote' for following senario.
Here is the routes file : quotes.js
const express = require('express');
const request = require('request');
const async = require('async');
const validator = require('validator');
const quote_router = express.Router();
const confg = require("../../confg/confg");
const quote = require("../models/mquotes");
const quotes_model = quote.quotes;
// host name - needs to be set up using the environment variable
const hostname = confg.hostname;
// route for "quotes/"
quote_router.route("/")
// get route : display the random quote
.get((req, res) => {
// display random quote
async.waterfall([
(callback) => {callback(null, {res});},
quote.count_quotes
], check_quote_exist
);
})
// post route : create a new quote
.post((req, res) => {
const doc_json = {author : validator.escape(req.body.quote_author), quote_text : validator.escape(req.body.quote_text)};
const params = {res, doc_json, quote_action : quote.create_quote};
add_edit_quote(params);
})
// put route : edit the quote
.put((req, res) => {
const doc_json = {author : validator.escape(req.body.quote_author), quote_text : validator.escape(req.body.quote_text)};
const params = {res, doc_json, quote_action : quote.update_quote, qid : req.body.quote_id};
add_edit_quote(params);
})
// delete quote : delete the quote
.delete((req, res) => {
const qid = req.body.qid;
const condition = {_id : qid};
async.waterfall([
(callback) => {callback(null, {res, condition});},
quote.delete_quote
], request_quote_list
);
});
// route for "quotes/list" : display quotes list
quote_router.get("/list/", (req, res) => {
// mention the main operation
let operation;
if(req.body.operation != 'undefined') {
operation = req.body.operation;
} else {
operation = "list_quotes";
}
async.waterfall([
(callback) => {callback(null, {res, operation});},
quote.list_quote
], display_quotes_list
);
});
// display the quotes list
const display_quotes_list = (err, params, quotes_list) => {
if (err) {return console.log(err);}
const res = params.res;
const operation = params.operation;
const header_msg = "List of all the quotes";
let alert_msg;
if(operation == "list_quotes") {
alert_msg = null;
} else if(operation == "delete_quote") {
alert_msg = "Quote has been deleted";
}
const params_out = {
page: "quote_list",
title: 'Quotes Manager',
host: hostname,
header_msg,
alert_msg,
quotes_list
};
res.render('index', params_out);
};
// send http request for quote list page
const request_quote_list = (err, params) => {
if (err) {return console.log(err);}
const res = params.res;
const operation = "delete_quote";
request.get('http://' + hostname + '/quotes/list/', {json:{operation}},
(error, response, body) => {
if (!error && response.statusCode == 200) {
res.send(body);
}
});
};
module.exports = quote_router;
This is not complete file. I have included only a portion of it.
And her is the model file : mquotes.js
const mongoose = require('mongoose');
// Define quote schema
const quoteSchema = new mongoose.Schema({
author: String,
quote_text: {type: String, required: true}
},
{timestamps: true}
);
const quote = {};
// Define quotes model
quote.quotes = mongoose.model('quotes', quoteSchema);
// error handler
error_handler = (callback, err, params, return_value) => {
if(err) { return callback(err);}
else {callback(null, params, return_value);}
};
// add quote - create
quote.create_quote = (params, callback) => {
const res = params.res;
const doc_json = params.doc_json;
quote.quotes.create(doc_json, (err, quotes_detail) => {
error_handler(callback, err, {res, operation : 'create_quote'}, quotes_detail);
});
};
// count the number of quotes
quote.count_quotes = (params, callback) => {
quote.quotes.count({}, (err, quotes_count) => {
error_handler(callback, err, params, quotes_count);
});
};
// delete quote - delete - id
quote.delete_quote = (params, callback) => {
quote.quotes.remove(params.condition, (err, query) => {
error_handler(callback, err, params);
});
};
// list quote - find
quote.list_quote = (params, callback) => {
quote.quotes.find({}, (err, quotes_list) => {
error_handler(callback, err, params, quotes_list);
});
};
// find quote by id
quote.quote_by_id = (params, callback) => {
quote.quotes.findById(params.qid, (err, quotes_detail) => {
error_handler(callback, err, params, quotes_detail);
});
};
// returns the detail of random quote
quote.random_qoute = (params, callback) => {
const random_number = params.random_number;
// select one quote after skipping random_number of times
quote.quotes.findOne({}, (err, quotes_detail) => {
error_handler(callback, err, params, quotes_detail);
}).skip(random_number);
};
// update quote - update - id
quote.update_quote = (params, callback) => {
const options = {new: true};
const qid = params.qid;
const update_json = params.doc_json;
quote.quotes.findByIdAndUpdate(qid, {$set: update_json}, options, (err, quotes_detail) => {
params.operation = 'update_quote';
error_handler(callback, err, params, quotes_detail);
});
};
module.exports = quote;
I have installed mocha globally. Now, I want to test the model. Lets take the quote.list_quote function for example.
const mongoose = require('mongoose');
const chai = require('chai');
const sinon = require('sinon');
const expect = chai.expect; // use the "expect" style of Chai
const mquotes = require('./../../app/models/mquotes');
describe('Tests for quote models', () => {
describe("List quote", () => {
it('list_quote() should return list of quotes', () => {
});
});
});
Can anyone tell me about my coding practice too. I mean the way I use functions and modules.

Answer 1

First of all, you should try to use statics methods. And after that, you should use sinon-mongoose and sinon-as-promised if you want to use Promise in mongoose.
And this is my sample code and test with mocha, chai, and sinon. Hope useful for you.
model.js
var Schema = new mongoose.Schema({
name: String,
created_at: {
type: Date,
default: Date.now
},
updated_at: {
type: Date,
default: Date.now
}
});
Schema.statics.findByName = function(name, cb) {
this.findOne({
name: name
})
.exec()
.then(function getTemplate(template) {
if (!template) {
var error = new Error('Not found template by name: "' + name + '"');
error.status = 404;
return cb(error);
}
return cb(null, template);
})
.catch(function catchErrorWhenFindByTemplateName(error) {
error.status = 500;
return cb(error);
});
}
module.exports = mongoose.model('model', Schema);
test.js
var expect = require('chai').expect,
sinon = require('sinon'),
mongoose = require('mongoose');
require('sinon-as-promised');
require('sinon-mongoose');
var Model = require('../../app/models/model');
describe('Model', function () {
describe('static methods', function () {
describe('#findByName', function () {
var ModelMock;
beforeEach(function () {
ModelMock = sinon.mock(Model);
});
afterEach(function () {
ModelMock.restore();
});
it('should get error status 404 if not found template', function (done) {
var name = 'temp';
ModelMock
.expects('findOne').withArgs({name: name})
.chain('exec')
.resolves(null);
Model.findByName(name, function (error) {
expect(error.status).to.eql(404);
ModelMock.verify();
done();
});
});
it('should get message not found template if name is not existed', function (done) {
var name = 'temp';
ModelMock
.expects('findOne').withArgs({name: name})
.chain('exec')
.resolves(null);
Model.findByName(name, function (error) {
expect(error.message).to.match(/Not found template by name/gi);
ModelMock.verify();
done();
});
});
it('should get template when name is existed', function (done) {
var name = 'temp';
ModelMock
.expects('findOne').withArgs({name: name})
.chain('exec')
.resolves('SUCCESS');
Model.findByName(name, function (error) {
expect(error).to.be.null;
ModelMock.verify();
done();
});
});
it('should get error status 500 when model crashed', function (done) {
var name = 'temp';
ModelMock
.expects('findOne').withArgs({name: name})
.chain('exec')
.rejects(new Error('Oops! Crashed'));
Model.findByName(name, function (error) {
expect(error.status).to.eql(500);
ModelMock.verify();
done();
});
});
});
});
});