Develop Reference

Create loop in Javascript to use with imap-simple nodejs package

Firstly, some background as to what my test script will cover.
Pressing a button on a website will fire off an email to a test mailbox.
This email can take anything between 10 and 30 minutes to arrive in the test mailbox.
So using the following code from imap-simple ;
'get new email info': function(browser) {
imaps.connect(config).then(function (connection) {
return connection.openBox('INBOX').then(function () {
var searchCriteria = ['UNSEEN'];
var fetchOptions = {
bodies: ['HEADER', 'TEXT'],
markSeen: false
};
return connection.search(searchCriteria, fetchOptions).then(function (results) {
var subjects = results.map(function (res) {
return res.parts.filter(function (part) {
return part.which === 'HEADER';
})[0].body.subject[0];
});
console.log(subjects);
Correctly comes back with a blank subjects array, as the email hasn't been received by the test mailbox yet.
Adding a 30 minutes pause to the beginning of the script 'works', as after the 30 minutes the subjects array is populated as the email is (99.99% of the time) sent within a 30 minute window.
However, it is definitely far from ideal as the email might be received within 15 minutes, meaning the test is 'wasting' 15 minutes.
So what I'd ideally like to do is write some form of loop (?) that tests if the subjects array is populated or not.
So if the array is populated, carry on with the rest of the test script (which entails testing that the array contains a certain text).
If the array is not populated, wait for another minute before trying again.
Continue this trying every minute until the array is populated.
I've tried setInterval, For loops, While loops, etc but I can't seem to get them to work and I'm out of ideas to be honest.
Any advice, help, references would be greatly appreciated and any more info can be promptly added if required.

One way to do that could be using recursion.
const createPromise = ms => new Promise((resolve, reject) => {
setTimeout(() => resolve(ms), ms)
});
function findUnseenEmails(connection) {
return connection.openBox('INBOX').then(function () {
var searchCriteria = [
'UNSEEN'
];
var fetchOptions = {
bodies: ['HEADER', 'TEXT'],
markSeen: false
};
return connection.search(searchCriteria, fetchOptions).then(function (results) {
var subjects = results.map(function (res) {
return res.parts.filter(function (part) {
return part.which === 'HEADER';
})[0].body.subject[0];
});
console.log(subjects);
return subjects.length > 0 ? subjects : createPromise(5000).then(function() { return findUnseenEmails(connection)});
});
});
}
imaps.connect(config).then(function (connection) {
return findUnseenEmails(connection);
}).then((subjects) => console.log('finished', subjects));
Of course there is a possibility and danger of stack overflow, but in such scenario feel free to come back to stack overflow to find here with the help of our community non-recursive solution.
Result:
EDIT:
Answering your question regarding closing connection:
I'd do it like this (in findUnseenEmails function)
if (subjects.length > 0) {
connection.end();
return subjects;
} else {
return createPromise(5000).then(function() { return findUnseenEmails(connection)});
}

Generate tests based on the result of a promise in Jest JS

Right now I have a simple.test.js file that generates calls to test based on simplified call/response files (so we don't need to write a .test.js for each of these simplified cases). For reference I'll include the file here:
'use strict';
const api = require('./api');
const SCRIPT_NAME_KEY = Symbol('script name key'),
fs = require('fs'),
path = require('path');
const generateTests = (dir) => {
const relPath = path.relative(__dirname, dir);
let query, resultScripts = [], resultSqls = [];
for (let entry of fs.readdirSync(dir)) {
if (entry[0] === '-')
continue;
let fqEntry = path.join(dir, entry);
if (fs.statSync(fqEntry).isDirectory()) {
generateTests(fqEntry);
continue;
}
if (entry === 'query.json')
query = fqEntry;
else if (entry.endsWith('.sql'))
resultSqls.push(fqEntry);
else if (entry.endsWith('.js') && !entry.endsWith('.test.js'))
resultScripts.push(fqEntry);
}
if (!query && resultScripts.length === 0 && resultSqls.length === 0)
return;
if (!query)
throw `${relPath} contains result script(s)/sql(s) but no query.json`;
if (resultScripts.length === 0 && resultSqls.length === 0)
throw `${relPath} contains a query.json file but no result script(s)/sql(s)`;
try {
query = require(query);
} catch (ex) {
throw `${relPath} query.json could not be parsed`;
}
for (let x = 0; x < resultScripts.length; x++) {
let scriptName = path.basename(resultScripts[x]);
console.log('scriptName', scriptName);
try {
resultScripts[x] = require(resultScripts[x]);
} catch (ex) {
throw `${relPath} result script ${scriptName} could not be parsed`;
}
resultScripts[x][SCRIPT_NAME_KEY] = scriptName;
}
test(`ST:${relPath}`, () => api.getSqls(query).then(resp => {
if (resultScripts.length === 0) {
expect(resp.err).toBeFalsy();
expect(resp.data).toBeAllValidSql();
} else {
for (const script of resultScripts)
expect({ n: script[SCRIPT_NAME_KEY], r: script(resp, script[SCRIPT_NAME_KEY]) }).toPass();
}
for (const sql of resultSqls)
expect(resp.data).toIncludeSql(fs.readFileSync(sql, 'utf8'));
}));
};
expect.extend({
toPass(actual) {
const pass = actual.r === void 0 || actual.r === null || !!actual.r.pass;
return {
pass: pass,
message: pass ? null : () => actual.r.message || `${actual.n} check failed!`
}
}
});
generateTests(path.join(__dirname, 'SimpleTests'));
This works really great! It runs immediately when the .test.js file is loaded by Jest and generates a test for each folder containing the valid files.
However, I now have a need to generate a test per record in a database. From what I can tell most of the available modules that provide DB functionality work on the premise of promises (and reasonably so!). So now I need to wait for a query to come back BEFORE I generate the tests.
This is what I'm trying:
'use strict';
const api = require('./api');
api.getAllReportsThroughSideChannel().then((reports) => {
for (const report of reports) {
test(`${report.Name} (${report.Id} - ${report.OwnerUsername})`, () => {
// ...
});
}
});
However when I do this I get:
FAIL ./reports.test.js
● Test suite failed to run
Your test suite must contain at least one test.
at ../node_modules/jest/node_modules/jest-cli/build/TestScheduler.js:256:22
As one might expect, the promise gets created but doesn't get a chance to actually trigger the generation of tests until after Jest has already expected to receive a list of tests from the file.
One thing I considered was to have a test that itself is a promise that checks out all the reports, but then it would fail on the first expect that results in a failure, and we want to get a list of all reports that fail tests. What we really want is a separate test for each.
I guess ultimately the question I want to know is if it is possible for the generation of tests to be done via a promise (rather then the tests themselves).
There is a TON of resources for Jest out there, after searching I didn't find anything that applies to my question, so apologies if I just missed it somehow.

Ok, after a few days of looking through docs, and code, it's looking more and more like this simply can not be done in Jest (or probably more correctly, it goes counter to Jest's testing philosophies).
As such, I have created a step prior to running the jest runtime proper, that simply downloads the results of the query to a file, then I use the file to synchronously generate the test cases.
I would LOVE it if someone can propose a better solution though.

NodeJS and Mongoose Callback inside a For Loop

So here's the problem. I have a REST API that handles a booking creation, however, before saving the booking inside mongo it validates if there is a clash with another booking.
exports.create = function(req, res) {
var new_type = new Model(req.body);
var newBooking = new_type._doc;
//check if the new booking clashes with existing bookings
validateBooking.bookingClash(newBooking, function(clash){
if(clash == null) // no clashes, therefore save new booking
{
new_type.save(function(err, type) {
if (err)
{
res.send(err); //error saving
}
else{
res.json(type); //return saved new booking
}
});
}
else //clash with booking
{
//respond with "clashDate"
}
});
};
Here you have the validation function to check if there is a clash with bookings on the same day:
exports.bookingClash = function (booking, clash) {
//find the bookings for the same court on the same day
var courtId = (booking.courtId).toString();
Model.find({courtId: courtId, date: booking.date}, function(err, bookings) {
if(err == null && bookings == null)
{
//no bookings found so no clashes
clash(null);
}
else //bookings found
{
//for each booking found, check if the booking start hour falls between other booking hours
for(var i = 0; i<bookings.length ; i++)
{
//here is where I check if the new booking clashes with bookings that are already in the DB
{
//the new booking clashes
//return booking date of the clash
clash(clashDate); //return the clashDate in order to tell the front-end
return;
}
}
//if no clashes with bookings, return null
clash(null);
}
});
};
So, ALL of this works with one single new booking. However, now I want to be able to handle a recursive booking (booking that is made weekly). I have recreated the "create" function and call the validateBooking.bookingClash function inside a for loop.
Unfortunately, when I run this, it calls the bookingClash function perfectly, but when it reaches the line making the search in the database:
Model.find({courtId: courtId, date: booking.date}, function(err, bookings)
It does not wait for the callback and before handling the response "clash", makes i++ and continues.
How can I make it work and wait for the callback?
var array = req.body;
var clashes = [];
for(var i = 0; i<array.length;i++)
{
validateBooking.bookingClash(array[i], function(clash)
{
if(clash)
{
clashes.push(clash);
}
else{
console.log("no clash");
}
}
}

Seems like a basic async call problem, for loops do not wait for callbacks to be called.
You could use async 'series' function for exmaple instead of the for loop. This way each find will get called after the previous one.
Mongoose also has a promise based syntax which can help you : http://mongoosejs.com/docs/promises.html

You Can use async eachSeries
async.eachSeries(users, function iterator(user, callback) {
if(something) {
//thing you want to do
callback();
} else {
callback();
}
}

Since you are using callback functions there are two ways you could try to solve this:
1) use some external library that allows you to perform an asynchronous map operation and run all the checks for each clash. Once they are done check the combined results for a clash and proceed accordingly
I would suggest using the async library
your code would look something like:
async.map(array,(entry,callback) => validateBooking.bookingClash(entry,callback),(error,mappingResults)=>{...})
2) you could try to change this function to a recursive one
`function recursiveValidation(arrayToCheck,mainCallback){
if(arrayToCheck.length === 0) {
return cb(null} // end of array without errors
}
validateBooking.bookingClash(_.head(arrayToCheck), function(clash)
{
if(clash)
{
return mainCallback(clash);
}
return recursiveValidation(_.tail(arrayToCheck),mainCallback);
}
}`
The above code is just a mockup but it should show the point.
The _ is lodash

No need to changing anything in your code except the declaration use let instead of var and your loop should work.
var array = req.body;
var clashes = [];
`
for(**let** i = 0; i<array.length;i++)
{
validateBooking.bookingClash(array[i], function(clash)
{
if(clash)
{
clashes.push(clash);
}
else{
console.log("no clash");
}
}
}`
You have to understand the difference between let and var. Also why var cannot be used for running async code inside a loop.
Learn about let: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/let

I found the way to get this done after trying all of your answers.
What I had to do was this:
validateBooking.singleBooking(new_type._doc, newBookingClubId, function (clash) {
if (clash == null) // no clash
{
validatorArray.push(0);
if(validatorArray.length == array.length) //has received everything from mongo
{
console.log("Clashes: " + clashes.toString());
if(validatorArray.indexOf(1) > -1) //contains a clash
{
var error = {
code: 409,
message: "409 Conflict",
clashes: clashes
};
errorsHandler.handleError(error, res);
}
This way, I created an array called "validatorArray" that was called every time I received something back from Mongo.
This way I could easily compare the length of the array of bookings and the validatorArray length. When they were equal, it meant that it had received everything back from mongo and could send back the response.
Thanks for the help!

Jasmine unit test fails when spying on a service method

I have an Angular module, validation, which is declared like so:
(function(ns){
ns.validation = angular.module("validation", []);
})(blog);
The module contains two services, validator and validationRulesProvider, which look like:
(function(module){
module
.factory("validationRulesProvider", function(){
var _getRules = function() {
return [{
isValid: function(post) {
return post.length > 0;
}
}];
};
return {
getRules: _getRules
};
});
})(blog.validation);
and
(function(module){
module
.factory("validator", ["validationRulesProvider", function(validationRulesProvider){
var _validate = function(post) {
var rules = validationRulesProvider.getRules();
for (var rule in rules) {
if (!rule.isValid(post)) {
return false;
}
}
return true;
};
return {
validate: _validate
};
}]);
})(blog.validation);
I am attempting to test (using Jasmine) that
The getRules method on validationRulesProvider is actually called from the validate method
The post parameter is run through each rule returned from said method
I have the following Jasmine test script:
describe("Validator: ", function(){
var _validator;
var _mockedValidationRulesProvider;
var _mockRule;
beforeEach(function(){
module("validation");
inject(function(validationRulesProvider){
_mockedValidationRulesProvider = validationRulesProvider;
});
_mockRule = jasmine.createSpy();
spyOn(_mockedValidationRulesProvider, "getRules")
.and
.returnValue([{
isValid: _mockRule
}]);
inject(function(validator){
_validator = validator;
});
});
describe("getRules - ", function(){
it("gets a collection of rules from the rules provider", function(){
_validator.validate("");
expect(_mockedValidationRulesProvider.getRules).toHaveBeenCalled();
});
it("should pass the post through each rule received from the rules provider", function(){
expect(_mockRule.calls.count()).toEqual(_mockedValidationRulesProvider.getRules().length);
});
});
});
So, I'm simply trying to create a fake implementation of validationRulesProvider.getRules. My trouble is that both of these tests fail. If I alter the line:
spyOn(_mockedValidationRulesProvider, "getRules")
.and
.returnValue([{
isValid: _mockRule
}]);
to simply be
spyOn(_mockedValidationRulesProvider, "getRules")
.and
.returnValue([]);
then the first of the two tests pass, as the loop in validator.validate will never be entered.
Karma gives the following output:
PhantomJS 1.9.8 (Windows 7) Validator: getRules - gets a collection of rules from the rules provider FAILED
TypeError: 'undefined' is not a function (evaluating 'rule.isValid(post)')
at C:/Users/User/JS/Angular/Learning/blogsite/scripts/validation/validator.js:8
at C:/Users/User/JS/Angular/Learning/blogsite/scripts/tests/validator.test.js:32
PhantomJS 1.9.8 (Windows 7) Validator: getRules - should pass the post through each rule received from the rules provider FAILED
Expected 0 to equal 1.
at C:/Users/User/JS/Angular/Learning/blogsite/scripts/tests/validator.test.js:37
PhantomJS 1.9.8 (Windows 7): Executed 5 of 5 (2 FAILED) (0 secs / 0.039 secs)
I'm a bit of a loss as to why the tests are failing in the first instance because it seems like what I should be returning from the spy is an array of one object which contains an "isValid" function - which is exactly what is returned from the actual implementation of that function.
What am I doing wrong?

When you want to loop an array in javascript, you need to use javascript basic 'for loop' instead of 'for-in loop'.
The code in your validator factory should be like this.
for (var i = 0; i < rules.length; i++) {
var rule = rules[i];
if (!rule.isValid(post)) {
return false;
}
}

Meteor method reactivity doesn't work

I'm not experienced in Javascript but I've read a ton of articles about Meteor reactivity but still can't figure out why it is not working in my case.
When a new product is added, I want to be recalculated total cost and use it in the totalCost helper so it's almost real time visible in the browser.
Can someone please take a look at my code and try to figure out some logic error? Everything except the reactivity is working on my computer.
I have got this method in /models/Product.js :
Meteor.methods({
totalProductCost: function() {
var pipeline = [
{$match: {owner: Meteor.userId()}},
{$group: {_id: null, cost: {$sum: "$cost"}}}
];
var data = Products.aggregate(pipeline)["0"].cost;
return (data === undefined) ? 0 : data;
}
});
Then I've got layout.js in client folder:
if (Meteor.isClient) {
var handle = Meteor.subscribe("Products", Meteor.userId());
ProductManager = {
_productItems: null,
_dep: new Tracker.Dependency(),
getProducts: function () {
this._dep.depend();
return this._productItems;
},
setProducts: function (value) {
if (value !== this._productItems) {
this._productItems = value;
this._dep.changed();
}
},
getTotalCost: function () {
return ReactiveMethod.call('totalProductCost');
}
}
// TRACKER
Tracker.autorun(function () {
if (handle.ready()) {
ProductManager.setProducts(Products.find().fetch());
}
});
// HELPERS
Template.boxOverview.helpers({
"totalCost" : function () {
return ProductManager.getTotalCost();
},
});
}

It seems that you used a collection.aggregate in a method. If you need reactivity, you need to use a publication rather than a method (or you need to call the method each time you want to refresh). However, if you use your aggregation inside your publication (I assume you use a package for it) you will loose reactivity as well.
What I would advise you is to use a publication without aggregate function. You calculate your product cost by creating a new field and adding it to your cursor. Once, you do that, if you want to keep reactivity, it is necessary to use to use cursor.observeChanges() or just cursor.observe().
Have a look at this example:
var self = this;
// Modify the document we are sending to the client.
function filter(doc) {
var length = doc.item.length;
// White list the fields you want to publish.
var docToPublish = _.pick(doc, [
'someOtherField'
]);
// Add your custom fields.
docToPublish.itemLength = length;
return docToPublish;
}
var handle = myCollection.find({}, {fields: {item:1, someOtherField:1}})
// Use observe since it gives us the the old and new document when something is changing.
// If this becomes a performance issue then consider using observeChanges,
// but its usually a lot simpler to use observe in cases like this.
.observe({
added: function(doc) {
self.added("myCollection", doc._id, filter(doc));
},
changed: function(newDocument, oldDocument)
// When the item count is changing, send update to client.
if (newDocument.item.length !== oldDocument.item.length)
self.changed("myCollection", newDocument._id, filter(newDocument));
},
removed: function(doc) {
self.removed("myCollection", doc._id);
});
self.ready();
self.onStop(function () {
handle.stop();
});
This is taken from here.