My server has a route,
app.get(("/employees/:id"), (req, res) => {
console.log(req.paramas.id); //prints correctly
data.getEmployeeByNum(req.params.id).then((data) => {
res.json(data);
}).catch(function(reason) {
console.log("An error was encountered: " + reason);
});
});
And getEmployeeByNum() is defined as,
module.exports.getEmployeeByNum = function(num) {
return new Promise((reject, resolve) => {
var temp = [];
let j = 0;
for (let i = 0; i < employees.length; i++) {
if (employees[i].employeeNum == num) {
temp[j] = employees[i];
j++;
}
}
console.log("LENGTH IS: " + temp.length); //LENGTH IS: 1 (which is exactly what I need)
if (temp.length == 0) {
console.log("we bad");
reject("No results");
} else {
console.log("we good"); //prints this line
resolve(temp);
}
});
}
As you can note, console.log("we good"); gets called as it should, and my function resolves the array of one employee. But my call to this function catches it as an error, and prints An error was encountered: [object Object]. Any thoughts? Im breaking my head over this.
Im an idiot.
module.exports.getEmployeeByNum = function(num) {
return new Promise((resolve, reject) => {
not
module.exports.getEmployeeByNum = function(num) {
return new Promise((reject, resolve) => {
Related
My use case demands me to call an sql recursively till no rows are returned for which I have written the below code which due to async nature doesn't work as expected.
The piece of code which does this invocation is:
let Response = await getData(userId);
async function getData(userId) {
console.log("Invoking Get Data Function");
let arrayOfUserId = [userId];
let fetchMore = true,
j = 1;
let keyWithQoutes = -1;
return new Promise((resolve, reject) => {
do {
console.log(arrayOfUserId, j)
j++;
if (arrayOfUserId.length > 0) {
keyWithQoutes = arrayOfUserId.map((it) => {
return `'${it}'`;
});
}
const sql = ` Select userId from USER where reportingTo in (${arrayOfUserId})`;
console.log(' SQL Query ', sql);
con.query(sql, [], async(error, response) => {
if (error) {
fetchMore = false;
reject(error);
}
console.log(
" Response for ",
userId,
response,
response.length
);
if (response.length == 0) {
fetchMore = false;
resolve(arrayOfUserId);
}
else {
for (let i = 0; i < response.length; i++) {
console.log(response[i].userId);
arrayOfUserId.push(response[i].userId);
}
}
});
} while (fetchMore);
});
}
Hi I have a for loop in my node js application which calls an async function. I want to check a value and decide whether a customer is found or not. But the loop iterates until the last element. Hence my error loop is not working. I want the loop to check the response and then iterate the next loop.
for loop:
for (let i = 0; i < customerlookupresponse.data.length; i++) {
var customer = customerlookupresponse.data[i];
if (customer != undefined) {
console.log("customer.id :: " + customer.id)
var accountlookUpData = {
customerId: customer.id
};
customerAccountLookUpRequest(accountlookUpData).then(data => {
console.log("----" + i + " -- " + data);
if (data && data.status === 1) {
resolve(data);
return;
}else{
reject({
status: 404,
message: "Customer not found"
});
return;
}
});
} else {
reject({
status: 404,
message: "Customer not found"
});
return;
}
}
the async function:
async function customerAccountLookUpRequest(customerLookUpData) {
var accountLookUp = config.app.url;
let data = await axios.get(accountLookUp).then(accountLookUpResult => {
for (i = 0; i < accountLookUpResult.data.length; i++) {
var requestaccount = accountLookUpResult.data[i].accountNumber;
if (requestaccount == customerLookUpData.lookupAccount) {
accountLookUpResult.data[i].customerId = customerLookUpData.customerId;
accountLookUpResult.data[i].status = 1;
return accountLookUpResult.data[i];
}
}
});
return data;
}
I am new to node js and trying to understand the concept of async await. Please help.
An async function waits for a Promise to return. The function that has the loop should be declared as async and the customerAccountLookUpRequest function should return a promise. Then use the await operator to call the function. Simple example:
class some_class {
constructor() {
}
async my_loop() {
let _self = this;
for (let i = 0; i < customerlookupresponse.data.length; i++) {
let data = await _self.customerAccountLookUpRequest(accountlookUpData);
console.log("----" + i + " -- " + data);
}
}
customerAccountLookUpRequest(customerLookUpData) {
return new Promise((resolve, reject) => {
axios.get(accountLookUp).then(accountLookUpResult => {
resolve(accountLookUpResult);
});
});
}
}
i having Api Call which execute in For Loop some of the value which returns 10 sec itself some may take nearly 60 sec i have to maintain proper Timeout and clear session (i.e if results comes at 15 sec means it should goes to next input values and run the code) but currenly its waiting for 45 sec each single record how to optimize it
here my sample code :
if (selectedrows.length >= 1) {
for (var i = 0; i < selectedrows.length; i++) {
var myVar = setTimeout (function (k) {
var ob = { results: "Appending ..." };
child.update(selectedrows[k][4], selectedrows[k][4], ob);
var fullName = selectedrows[k][1] + ' ' + selectedrows[k][2];
math.ResultCall.async(fullName,function (err, res) {
if (err) throw err;
var returnedValue = JSON.parse(res);
console.log(returnedValue);
if(returnedValue.Result == null || returnedValue.Result.FOUND_Result == null)
{
console.log("None found")
}
else{
var obj = { results: “res” };
child.update(selectedrows[k][4], selectedrows[k][4], obj);
}
}
});
}, i * 45000,i);
}
}
Rephrasing your question, you need to return the data when your api gets resolved.
For this please go through https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/resolve
JavaScript, by default it work asynchronously because of its event loop.
You have promises and resolve to get notified when your api returns a data
Hope I helped :)
There are several approaches to implement the solution
1. Async-Await: in-case the records-processing order is important
for( let i=0; i<selectedrows.length; i++)
{
let ob = { results: "Appending ..." };
child.update(selectedrows[i][4], selectedrows[i][4], ob);
let fullName = selectedrows[i][1] + ' ' + selectedrows[i][2];
await new Promise((resolve,reject)=>
{
math.ResultCall.async(fullName,(err, res) => {
if (err) reject(err);
let returnedValue = JSON.parse(res);
console.log(returnedValue);
if(returnedValue.Result == null || returnedValue.Result.FOUND_Result == null) {
console.log("None found")
} else {
let obj = { results: “res” };
child.update(selectedrows[i][4], selectedrows[i][4], obj);
}
resolve();
});
}
**don't forget this means the wrapping function should be async as well (which returns a promise that can be resolved if necessary)
2.Promise.All: if the order is not important
let promArray = [];
for( let i=0; i<selectedrows.length; i++)
{
let ob = { results: "Appending ..." };
child.update(selectedrows[i][4], selectedrows[i][4], ob);
let fullName = selectedrows[i][1] + ' ' + selectedrows[i][2];
promArray.push( new Promise((resolve,reject)=>
{
math.ResultCall.async(fullName,(err, res) => {
if (err) reject(err);
let returnedValue = JSON.parse(res);
console.log(returnedValue);
if(returnedValue.Result == null || returnedValue.Result.FOUND_Result == null) {
console.log("None found")
} else {
let obj = { results: “res” };
child.update(selectedrows[i][4], selectedrows[i][4], obj);
}
resolve();
});
);
}
Promise.all(promArray);
** this will also return a Promise that can be resolved if necessary.
I am still pretty new to this, so forgive me if I dont' say this correctly. We have an array.reduce that calls a method with a returning promise that iterates through a list of files and post results to the db. Everything was working great, until it ran into a field that had an apostrophe in it and then the db insert fails. This is the field value. 'Expected 100002822' to be 100002822.'
I tried adding a replaceAll on the field and now get an error in the array.reduce.
Here is the .reduce
console.log('Found test results in ' + matches.length + ' files. Parsing and posting to the database now...');
var startTime = moment();
var parser = new Parser();
matches.reduce(function (p, val) {
return p.then(function () {
return parser.parseResults(val);
});
}, Promise.resolve()).then(function (finalResult) {
var endTime = moment();
var testDuration = moment.duration(endTime.diff(startTime));
console.log(chalk.blue('*** File parsing time: ' + testDuration.humanize() + ' ***'));
if (finalResult.insertSuccess == matches.length) {
var publishOut = {
totalFiles: matches.length,
totalTests: 0,
totalTestsSuccess: 0,
totalTestsFailed: 0
}
publishOut.totalTests += finalResult.totalTests;
publishOut.totalTestsSuccess += finalResult.testPassedCount;
publishOut.totalTestsFailed += finalResult.testFailedCount;
console.log(`Successfully inserted ${finalResult.insertSuccess} of ${publishOut.totalTests} test results.`);
// for (var i = 0; i < matches.length; i++) {
// var currentFile = `./testing/results/${matches[i]}`;
// fs.unlinkSync(currentFile);
// }
resolve(publishOut);
} else {
reject('Only ' + finalResult.insertSuccess + ' of ' + matches.length + ' successfully posted to the database');
}
}, function (err) {
reject('error in reduce', err);
});
I have tried several different ways of using the replaceAll with the same failure. It hits this code from the array.reduce
}, function (err) {
reject('error in reduce', err);
});
And this is the called method. The added code causing the failure in the .reduce is this Message = expectation.message.replaceAll("'", "");
protractorParser.prototype.parseResults = function (fileName) {
return new Promise((resolve, reject) => {
//console.log('In parseresults', fileName);
var currentFile = './testing/results/' + fileName
json.readFile(currentFile, function (err, obj) {
if (err != null) {
console.log('error reading file', err);
reject(err);
} else {
resolve(obj);
}
});
}).then(function (obj) {
var results = [];
for (var suite in obj) {
var specs = obj[suite].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 = '';
testResults.totalTests++;
if (assert.failedExpectations.length) {
const expectation = assert.failedExpectations[assert.failedExpectations.length - 1];
Passed = 0;
Message = expectation.message.replaceAll("'", "");
Stack = expectation.stack.split('\n')[1].trim();
testResults.testFailedCount++
} else {
testResults.testPassedCount++
}
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.then(() => {
//fs.unlinkSync(currentFile);
testResults.insertSuccess++;
//console.log('insertSuccess', testResults.insertSuccess);
},
err => { console.log('… 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).then(() => testResults);
});
};
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);
});
};