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Foreach with Promise not waiting on method results

I am trying to iterate through the JSON files generated by the protractor tests. I pull all the file names into an array and call a method that opens and parses through the each file, post the results to the database and pass back a passed/failed flag.
I have tried all the examples here
Make angular.forEach wait for promise after going to next object and still get the same results.
The method is actually called, but the results are not posted to the db. I have tested the parser.parseResults on an individual file and it successfully posted to the db, so it has to have something to do with the promise not resolving correctly.
Is it not possible to do something like this in the jasmine/protractor framework? Or do I have something wrong in the code?
I have included the code for my latest attempt.
Thank You
Christine
matches.reduce(function (p, val) {
console.log('val', val);
return p.then(function () {
return parser.parseResults(val);
});
}, Promise.resolve()).then(function (finalResult) {
console.log('finalResult = ', finalResult);
}, function (err) {
console.log('error in reduce',err);
});
parser.parseResults code
protractorParser.prototype.parseResults = function (fileName) {
return new Promise((resolve, reject) => {
console.log('In parseresults', fileName);
json.readFile(fileName, function (err, obj) {
try {
if (err != null) {
console.log('error reading file',err);
reject(err);
}
console.log('obj - ',obj);
var results = [];
var Passed = 0;
var Message = '';
var Stack = '';
for (var suite in obj) {
var specs = obj[suite].specs;
console.log('spec - ', specs);
if (specs.length > 0) {
for (var i = 0; i < specs.length; i++) {
var assert = specs[i];
var tcR = new RegExp(/TC[\d]+/);
var tc = assert.description.match(tcR);
if (!assert.failedExpectations.length) {
Passed = 1;
}
else {
assert.failedExpectations.forEach((expectation) => {
Message = expectation.message;
Stack = expectation.stack.split('\n')[1].trim();
})
Passed = 0;
}
if (tc != null) {
utility.TestDataManager.insertAutomationResults(tc[0], assert.description, Passed, process.env.testBuild,
'P', Message, Stack, 0, moment().utcOffset(config.get('settings.timeOffset')).format('YYYY-MM-DDTHH:mm:ss'), '')
.then(function (resp) {
resolve(Passed);
}, (err) => {
console.log('Posting to Database failed ', err);
reject(err);
});
} else {
console.log('no test case found for test: ' + assert.description + ' -- skipping');
reject(err);
}
}
}
}
}
catch (err) {
console.log('rejecting opening file');
reject(err);
}
});
})
}

If there is not exactly one suite in the obj, with exactly one spec, then your promise is either resolved not at all or multiple times.
Avoid wrapping too many things in the new Promise constructor - always promisify on the smallest possible level, and use promise chaining afterwards.
protractorParser.prototype.parseResults = function (fileName) {
return new Promise((resolve, reject) => {
console.log('In parseresults', fileName);
json.readFile(fileName, function (err, obj) {
if (err != null) {
console.log('error reading file', err);
reject(err);
} else {
resolve(obj);
}
});
}).then(function(obj) {
console.log('obj - ',obj);
var results = [];
for (var suite in obj) {
var specs = obj[suite].specs;
console.log('spec - ', specs);
for (let i = 0; i < specs.length; i++) {
const assert = specs[i];
const tcR = /TC[\d]+/;
const tc = assert.description.match(tcR);
let Passed = 1;
let Message = '';
let Stack = '';
if (assert.failedExpectations.length) {
const expectation = assert.failedExpectations[assert.failedExpectations.length-1];
Passed = 0;
Message = expectation.message;
Stack = expectation.stack.split('\n')[1].trim();
}
if (tc != null) {
const time = moment().utcOffset(config.get('settings.timeOffset')).format('YYYY-MM-DDTHH:mm:ss');
const promise = utility.TestDataManager.insertAutomationResults(tc[0], assert.description, Passed, process.env.testBuild, 'P', Message, Stack, 0, time, '');
results.push(promise.catch(err => {
console.log('Posting to Database failed ', err);
throw err;
}));
} else {
console.log('no test case found for test: ' + assert.description + ' -- skipping');
// I don't think you want to `throw err` here, right?
}
}
}
return Promise.all(results);
});
};

Node.js Function Flow

When I get a request, I want it to generate a 4-character code, then check if it already exists in the database. If it does, then generate a new code. If not, add it and move on. This is what I have so far:
var code = "";
var codeFree = false;
while (! codeFree) {
var chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
var code = "";
for (var i = 0; i < 4; i++) {
var rand = Math.floor(Math.random() * chars.length);
console.log(rand);
code += chars.charAt(rand);
}
console.log("Code: %s generated.", code);
client.execute("select * from codes where code=" + code, function(err, result) {
if (! err) {
if (result.rows.length > 0) {
codeFree = false;
} else {
codeFree = true;
}
} else {
console.log('DB ERR: %s', err);
}
console.log(codeFree);
});
console.log('here');
}
This does not do nearly what I want it to do. How can I handle something like this?

You are doing an async task.
When you have an asyncronous task inside your procedure, you need to have a callback function which is going to be called with the desired value as its argument.
When you found the free code, you call the function and passing the code as its argument, otherwise, you call the getFreeCode function again and passing the same callback to it. Although you might consider cases when an error happens. If your the db call fails, your callback would never get called. It is better to use a throw/catch mechanism or passing another argument for error to your callback.
You can achieve what you need to do by doing it this way:
function getFreeCode(callback) {
var chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
var code = "";
for (var i = 0; i < 4; i++) {
var rand = Math.floor(Math.random() * chars.length);
console.log(rand);
code += chars.charAt(rand);
}
console.log("Code: %s generated.", code);
client.execute("select * from codes where code="+code, function(err, result) {
if(!err) {
if(result.rows.length > 0) {
getFreeCode(callback);
} else {
callback(code);
}
}else {
console.log('DB ERR: %s', err);
}
console.log(codeFree);
});
console.log('here');
}
// in your main:
getFreeCode(function (code) {
console.log(' this code was free: ' + code)
})

I recommend you look into two alternatives to help deal with asynchronous code.
node generator functions using the 'yield' keyword
promises
Using generators requires running a recent version of node with the --harmony flag. The reason I recommend generators is because you can write code that flows the way you expect.
var x = yield asyncFunction();
console.log('x = ' + x);
The previous code will get the value of x before logging x.
Without yielding the console.log would write out x before the async function was finished getting the value for x.
Your code could look like this with generators:
var client = {
execute: function (query) {
var timesRan = 0;
var result = [];
return function () {
return setTimeout(function () {
result = ++timesRan < 4 ? ['length_will_be_1'] : [];
return result;
},1);
};
}
};
function* checkCode () {
var code;
var codeFree = false;
while(!codeFree) {
var chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
code = "";
for (var i = 0; i < 4; i++) {
var rand = Math.floor(Math.random() * chars.length);
console.log(rand);
code += chars.charAt(rand);
}
console.log("Code: %s generated.", code);
try {
var result = yield client.execute("select * from codes where code="+code);
codeFree = result.rows.length > 0 ? false : true;
}catch(e) {
console.log('DB ERR: %s', err);
} finally {
console.log(codeFree);
}
console.log('here');
}
}
checkCode().next();
You would leave off the client object. I only added that to make a working example that fakes an async call.
If you have to use an older version of node or do not like the yield syntax then promises could be a worthy option.
There are many promise libraries. The reason I recommend promises is that you can write code that flows the way you expect:
asyncGetX()
.then(function (x) {
console.log('x: ' + x);
});
The previous code will get the value of x before logging x.
It also lets you chain async functions and runs them in order:
asyncFunction1()
.then(function (result) {
return asyncFunction2(result)
})
.then(function (x) { /* <-- x is the return value from asyncFunction2 which used the result value of asyncFunction1 */
console.log('x: ' + x);
});
Your code could look like this with the 'q' promise library:
var Q = require('q');
var client = {
timesRan: 0,
execute: function (query, callback) {
var self = this;
var result = {};
setTimeout(function () {
console.log('self.timesRan: ' + self.timesRan);
result.rows = ++self.timesRan < 4 ? ['length = 1'] : [];
callback(null, result);
},1);
}
};
function checkCode () {
var deferred = Q.defer();
var codeFree = false;
var chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
var code = "";
for (var i = 0; i < 4; i++) {
var rand = Math.floor(Math.random() * chars.length);
console.log('rand: %s', rand);
code += chars.charAt(rand);
}
console.log("Code: %s generated.", code);
client.execute("select * from codes where code="+code, function(err, result) {
console.log('err: '+err+', result: ' + JSON.stringify(result));
console.log('result.rows.length: ' + result.rows.length);
if(!err) {
if(result.rows.length > 0) {
codeFree = false;
console.log('result.rows: %s, codeFree: %s', result.rows, codeFree);
checkCode();
} else {
codeFree = true;
console.log('line 36: codeFree: ' + codeFree);
deferred.resolve(code);
}
}else {
console.log('DB ERR: %s', err);
deferred.reject(err);
}
console.log(codeFree);
});
console.log('waiting for promise');
return deferred.promise;
}
checkCode()
.then(function (code) {
console.log('success with code: ' + code);
})
.fail(function(err) {
console.log('failure, err: ' + err);
});
Also omit the client object here. I only added that to make a working example that fakes an async call.
Promises and generators definitely take some time to get used to. It's worth it because they make the code a lot easier to follow in the end than code written with nested callbacks.

Extract common code from sails.js / mongodb

I'm current trying to use sails.js with mongodb, I need some custom mapReduce function to group data.
Now I could achieve what I want by using waterline's native function, but have some questions.
These function has only small variation actually, but I found myself keep repeating codes like the following one:
function getSomeData() {
// First-query
Log.native(function(err, logCollection) {
var mapFunction = function() {
function dateFormatter(date) {
return date.getFullYear() + "-" + (date.getMonth() + 1)
}
//! Generate Grouping Key
emit(dateFormatter(this.emb_date), this.bad_qty)
}
var reduceFunction = function (key, values) {
return Array.sum(values);
}
var outputControl = {
out: {inline: 1},
//! Filters
query: {order_type: product}
}
logCollection.mapReduce(mapFunction, reduceFunction, outputControl, function (err, result) {
if (err) {
callback(err);
return;
}
var resultSet = [];
//! post-processing
for (var i = 0; i < result.length; i++) {
//.....
}
callback(err, resultSet);
});
});
}
Second-query:
function getAnotherData() {
Log.native(function(err, logCollection) {
var mapFunction = function() {
//! Generate Grouping Key
emit(dateFormatter(this.product), this.bad_qty)
}
var reduceFunction = function (key, values) {
return Array.sum(values);
}
var outputControl = {
out: {inline: 1},
//! Filters
query: {order_type: product}
}
logCollection.mapReduce(mapFunction, reduceFunction, outputControl, function (err, result) {
if (err) {
callback(err);
return;
}
var resultSet = [];
//! post-processing
for (var i = 0; i < result.length; i++) {
//......
}
callback(err, resultSet);
});
});
}
As you can see, these two snippet shares lots of common code, only has difference in three place (Generate grouping key, filters, post-process).
So I would really like to extract the common part to make my code cleaner, but have no success.
I first try to make dateFromatter is provided by a callback instead of hard-coding like the following:
function dateFormatter(data) {
return data.emb_date.getFullYear() + "-" + (data.emb_date.getMonth() + 1)
}
function getSomeData(groupingKey) {
// First-query
Log.native(function(err, logCollection) {
var mapFunction = function() {
//! Generate Grouping Key
emit(groupingKey(this.emb_date), this.bad_qty)
}
var reduceFunction = function (key, values) {
return Array.sum(values);
}
var outputControl = {
out: {inline: 1},
//! Filters
query: {order_type: product}
}
logCollection.mapReduce(mapFunction, reduceFunction, outputControl, function (err, result) {
if (err) {
callback(err);
return;
}
var resultSet = [];
//! post-processing
for (var i = 0; i < result.length; i++) {
//.....
}
callback(err, resultSet);
});
});
}
But without any luck, I keep getting error like the following one:
MongoError: exception: ReferenceError: groupingKey is not defined near 'emit(groupingKey(this), this.bad_qty' (line 3)
at Object.toError (/home/brianhsu/zh800/dashboard/node_modules/sails-mongo/node_modules/mongodb/lib/mongodb/utils.js:114:11)
What should I do if I would like to reduce those duplicate part of code?

Finally I found that I need pass the option called 'scope' to mongodb, I come up with the following solution which works quite well.
exports.defineOn = function(options) {
var model = options.model
var groupingFunction = options.groupingFunction
var mongoFilters = options.mongoFilters
var customFilter = options.customFilter
var converter = options.converter
var sorting = options.sorting
return function(callback) {
model.native(function(err, collection) {
var mapFunction = function() { emit(groupingFunction(this), this.bad_qty) }
var reduceFunction = function(key, values) { return Array.sum(values); }
var mapReduceOptions = {
out: {inline: 1},
query: mongoFilters,
scope: {
groupingFunction: groupingFunction,
mongoFilters: mongoFilters,
customFilter: customFilter,
converter: converter
}
}
var processCallback = function (err, result) {
if (err) {
callback(err);
return;
}
if (sorting) {
result.sort(sorting);
}
var resultSet = [];
for (var i = 0; i < result.length; i++) {
if (customFilter && customFilter(result[i])) {
resultSet.push(converter(result[i]));
} else if (!customFilter) {
resultSet.push(converter(result[i]));
}
}
callback(err, resultSet);
}
collection.mapReduce(mapFunction, reduceFunction, mapReduceOptions, processCallback);
});
}
}
Usage:
function machineDetail (year, month, date, machine, callback) {
var startDate = new Date(+year, +(month-1), +date);
var endDate = new Date(+year, +(month-1), (+date) + 1);
var mapReducer = MapReducer.defineOn({
model: Log,
groupingFunction: function(data) {
return {date: data.emb_date, error: data.defact_id};
},
mongoFilters: {
mach_id: machine,
emb_date: {$gte: startDate, $lt: endDate}
},
converter: function (data) {
return {
name: data._id,
value: data.value,
};
}
});
mapReducer(callback);
}

NodeJS - Deferred function inside a loop

I have a conceptual problem with NodeJS... I need to call a deferred function within a loop and use the response for the next iteration. How can I do that without blocking? Here is what I did but of course, response.rev doesn't get updated for the next iteration:
first.function().then(function(response) {
for (var int = 0; int < $scope.files.length; int++) {
call.function(response.rev).then(function (res) {
response.rev = res.rev;
}, function (reason) {
console.log(reason);
});
}
});
Edit, my real code with Benjamin's help (still not working):
pouchWrapper.updateClient(clientManager.clientCleaner($scope.client)).then(function(response) {
if ($scope.files != null) {
var p = $q.when();
for (var int = 0; int < $scope.files.length; int++) {
var doc = $scope.files[int].slice(0, $scope.files[int].size);
p = p.then(function(formerRes){
return pouchWrapper.uploadFiletoDoc($scope.client._id, $scope.contract.policy_number + '&' + $scope.damage.number + '-' + $scope.files[int].name, res.rev, doc, $scope.files[int].type).then(function (res) {
return res;
}, function (reason) {
console.log(reason);
});
});
}
return p;
}
});

You use .then for that. .then is the asynchronous version of the semicolon:
first.function().then(function(response) {
var p = $q.when(); // start with an empty promise
for (var int = 0; int < $scope.files.length; int++) {
p = p.then(function(formerValue){
return call.function(formerValue).then(function (res) {
// use res here as the _current_ value
return res; // return it, so that the next iteration can use it;
});
});
}
return p; // this resolves with the _last_ value
});

WinJS return in promise array

I have a problem with returning array in Winjs promise and I don't have any idea what is wrong with my code. When i create a promise and do .done or .then my promise does nothing.
Code :
function getSth(array) {
return new WinJS.Promise(function () {
var dbPath = Windows.Storage.ApplicationData.current.localFolder.path + '\\_db.sqlite';
var i = 0;
SQLite3JS.openAsync(dbPath)
.then(function (db) {
console.log('DB opened');
return db.eachAsync('SELECT * FROM sthh;', function (row) {
array[i++] = row.sth;
console.log('Get a ' + row.sth);
});
})
.then(function (db) {
console.log('close the db');
db.close();
}).then(function () {
return array;
});
return array;
})
}
And in other file I just do something like that :
var array = [];
var z = getSth(array).then(function () {
console.log("AAA");
for (var i = 0; i < array.length; console.log("#" + array[i]), i++);
});
I will be very gratefull for any suggestion.

I assume you don't want to return immediately and instead want to return the array once it is full of elements?
I think you want to write code that is more like this:
function getSth(array) {
var dbPath = Windows.Storage.ApplicationData.current.localFolder.path + '\\_db.sqlite';
var i = 0;
return SQLite3JS.openAsync(dbPath)
.then(function (db) {
console.log('DB opened');
return db.eachAsync('SELECT * FROM sthh;', function (row) {
array[i++] = row.sth;
console.log('Get a ' + row.sth);
});
})
.then(function (db) {
console.log('close the db');
db.close();
}).then(function () {
return array;
});
}