This question already has answers here:
Why is my variable unaltered after I modify it inside of a function? - Asynchronous code reference
(7 answers)
Closed 2 years ago.
app.post('/api/edit-profile', regularFunctions, async function (req, res) {
let email = req.body.email
let password_current = req.body.password_current
connection.query('SELECT * FROM accounts WHERE id = ?', req.body.id, async function (err, results) {
if (results.length > 0) {
bcrypt.compare(password_current, results[0].password, async function (err, isMatch) {
if (err) {
res.send('Unable to save settings')
res.end();
throw err
} else if (!isMatch) {
res.send('Password doesn\'t match.')
res.end();
} else {
let changed = []
// Password matches
if (req.body.password_new) {
let newPassword = req.body.password_new
let hashed_password = await hashPassword(newPassword)
connection.query('UPDATE accounts SET password = ? WHERE id = ?', [hashed_password, req.body.id], async function (error, results) {
if (results.affectedRows && results.affectedRows > 0) {
changed.push('password')
} else {
res.send('Unable to save settings')
res.end();
}
})
}
if (req.body.license_key) {
let newKey = req.body.license_key
axios.get(`https://voltcloud.net/api/hosting/check-key/${newKey}`, {
headers: {
authorization: 'Y1wUo3joP99JHiGM2orji0UYTey9gdqY'
}
}).then(function (response) {
let data = response.data
if (typeof data === 'object') {
if (data.active === 1) {
axios({
method: 'post',
url: `https://voltcloud.net/api/hosting/activate-key/${newKey}`,
headers: {
authorization: 'Y1wUo3joP99JHiGM2orji0UYTey9gdqY'
}
}).then(async function (response) {
if (response.data === 'Success') {
connection.query('UPDATE accounts SET license_key = ? WHERE id = ?', [newKey, req.body.id], async function (error, results) {
if (results.affectedRows && results.affectedRows > 0) {
changed.push('license key')
} else {
res.send('Unable to save settings')
res.end();
}
})
} else if (data === 'License already active!') {
res.send('License key is already active!')
res.end();
} else if (data === 'Failed to update key.') {
res.send('Unable to save settings')
res.end();
} else {
res.send('Unable to save settings')
res.end();
}
});
}
}
})
}
connection.query('UPDATE accounts SET email = ? WHERE id = ?', [email,req.body.id], async function (error, results) {
if (results.affectedRows && results.affectedRows > 0) {
changed.push('email')
} else {
res.send('Unable to save settings')
res.end();
}
});
let finalTxt = 'Successfully changed, '
if (changed.length > 1) {
changed.forEach(function (txt, index) {
if (index === 0) {
finalTxt = finalTxt + txt
} else if (index === 2) {
finalTxt = finalTxt + `and ${txt}.`
}
})
} else if (changed.length === 1) {
finalTxt = `Successfully changed ${changed[0]}.`
}
res.send(finalTxt)
res.end();
}
})
}
})
});}
I know this might seem like a very easy problem to some expert coders, but I am sort of new to this whole async and synchronous thing. Why is it that the "changed" array doesn't update even though it's being pushed to after the functions run? What I'm trying to do is have it only return one string that can be shown on the client-side but it doesn't seem to be changing it and only returning the "Successfully changed, "
This function confused me, as it has a lot of responsabilities as Mike 'Pomax' Kamermans pointed out, but I found the problem:
The connection.query method is non-blocking, meaning it will not wait for it's execution to end for it to advance to the next instructions.
When you are using async methods and Promise, it's nice to try and keep consistency over the methods (avoid mixing callback functions and async/await). I've refactored it over what it should look like if using async/await:
app.post('/api/edit-profile', regularFunctions, async function (req, res) {
let email = req.body.email
let password_current = req.body.password_current
let results = await executeQuery(connection, 'SELECT * FROM accounts WHERE id = ?', [req.body.id]);
if (results.length > 0) {
let isMatch = await comparePassword(password_current, results[0].password);
if (!isMatch) {
throw new Error(`Password doesn't match`);
}
let changed = []
// Password matches
if (req.body.password_new) {
let newPassword = req.body.password_new
let hashed_password = await hashPassword(newPassword)
let results = await executeQuery(connection, 'UPDATE accounts SET password = ? WHERE id = ?', [hashed_password, req.body.id]);
if (results.affectedRows && results.affectedRows > 0) {
changed.push('password')
} else {
throw new Error('Unable to save settings');
}
}
if (req.body.license_key) {
let newKey = req.body.license_key
let response = await axios.get(`https://voltcloud.net/api/hosting/check-key/${newKey}`, {
headers: {
authorization: '<redacted>'
}
});
let data = response.data
if (typeof data === 'object') {
if (data.active === 1) {
let response = await axios({
method: 'post',
url: `https://voltcloud.net/api/hosting/activate-key/${newKey}`,
headers: {
authorization: '<redacted>'
}
})
if (response.data === 'Success') {
let results = await executeQuery(connection, 'UPDATE accounts SET license_key = ? WHERE id = ?', [newKey, req.body.id]);
if (results.affectedRows && results.affectedRows > 0) {
changed.push('license key')
} else {
throw new Error('Unable to save settings');
}
} else if (data === 'License already active!') {
throw new Error('License key is already active!');
} else if (data === 'Failed to update key.') {
throw new Error('Unable to save settings');
} else {
throw new Error('Unable to save settings');
}
}
}
}
let results = await executeQuery(connection, 'UPDATE accounts SET email = ? WHERE id = ?', [email,req.body.id]);
if (results.affectedRows && results.affectedRows > 0) {
changed.push('email')
} else {
throw new Error('Unable to save settings');
}
let finalTxt = 'Successfully changed, '
if (changed.length > 1) {
changed.forEach(function (txt, index) {
if (index === 0) {
finalTxt = finalTxt + txt
} else if (index === 2) {
finalTxt = finalTxt + `and ${txt}.`
}
})
} else if (changed.length === 1) {
finalTxt = `Successfully changed ${changed[0]}.`
}
res.send(finalTxt)
res.end();
}
});
function executeQuery(conn, sql, params) {
return new Promise((resolve, reject) => {
conn.query(sql, params, function (err, data) {
if (err != null) {
return reject(err);
}
return resolve(data);
});
});
}
function comparePassword(val1, val2) {
return new Promise((resolve, reject) => {
bcrypt.compare(val1, val2, function (err, isMatch) {
if (err != null) {
return reject(err);
}
resolve(isMatch);
});
})
}
Notice that we're not using callback functions at all, and even where we don't have native Promise-based functions (i.e. mysql connection), we're delegating to a function that proxies the callback to deliver a Promise and keep consistency over the final implementation.
The original code isn't waiting for the two if branches to complete before sending the response. It's hard to structure code like this in callbacks, due to the nesting.
Try using async functions and await wherever possible. It allows for much more readable code and error handling is much easier. So this answer is more code review than a simple fix for your issue.
Split out some generic helper code that will be useful in other routes:
// Generate errors for the web, with context
function responseError(message, status, data){
const error = new Error(message)
error.status = status
for (const key in data){
error[key] = data[key]
}
return error
}
// Turn mysql callbacks into promises (or use util.promisify)
async function runQuery(query, values){
return new Promise((resolve, reject) => {
connection.query(query, values, function(error, results){
if (error) return reject(error)
return resolve(results)
})
})
}
async function runUpdateQuery(query, values){
const results = await runQuery(query, values)
if (!results) throw responseError('No update result', 500, { query })
if (!results.affectedRows) throw responseError('No affected rows', 400, { query })
return results
}
The code from the two if conditions can be easily separated, as well as the other account operations.
async function apiAuthUserId(id, password){
const results = await runQuery('SELECT * FROM accounts WHERE id = ?', id)
if (!results.length) throw responseError('No account', 400, { id })
const isMatch = await bcrypt.compare(password_current, results[0].password)
if (!isMatch) throw responseError('Password doesn\'t match', 400)
return true
}
async function apiUpdatePassword(id, password){
let newPassword = req.body.password_new
let hashed_password = await hashPassword(newPassword)
await runUpdateQuery('UPDATE accounts SET password = ? WHERE id = ?', [hashed_password, req.body.id])
return id
}
async function apiUpdateEmail(id, email){
await runUpdateQuery('UPDATE accounts SET email = ? WHERE id = ?', [email, id])
return email
}
async function apiUpdateLicenseKey(id, licenseKey){
const response_license = await axios.get(`https://voltcloud.net/api/hosting/check-key/${licenseKey}`, {
headers: {
authorization: 'somekey'
}
})
const data = response_license.data
if (!data) {
throw responseError('No license key response data', 500, { response: response_license })
}
if (data.active !== 1) {
throw responseError('License key not active', 400, { key: licenseKey })
}
const response_activate = await axios({
method: 'post',
url: `https://voltcloud.net/api/hosting/activate-key/${licenseKey}`,
headers: {
authorization: 'somekey'
}
})
switch (response_activate.data){
case 'License already active!':
throw responseError('License key is already active!', 400, { response: response_activate })
case 'Failed to update key.':
throw responseError('Unable to save settings!', 400, { response: response_activate })
case 'Success':
await runUpdateQuery('UPDATE accounts SET license_key = ? WHERE id = ?', [licenseKey, req.body.id])
return licenseKey
default:
throw responseError('Unable to save settings!', 500, { response: response_activate })
}
}
Then your route code can be a bit cleaner and show what needs to be done, rather than how to do it all.
app.post('/api/edit-profile', regularFunctions, async function (req, res) {
const changed = []
try {
const { id, email, password_current } = req.body
await apiAuthUserId(id, password_current)
// Password matches
if (req.body.password_new) {
await apiUpdatePassword(id, req.body.password_new)
changed.push('password')
}
// License key
if (req.body.license_key) {
await apiUpdateLicenseKey(id, req.body.license_key)
changed.push('license key')
}
await apiUpdateEmail(id, email)
changed.push('email')
let finalTxt = `Successfully changed ${changed.join(' and ')}.`
res.send(finalTxt)
}
catch (error) {
// If your not using transactions, might need to deal with partial `changed` responses here.
console.error('Error /api/edit-profile', error)
res.status(error.status||500).send(`Error: ${error.message}`)
}
});
trying to test nodejs module.export function that will return based on request but it throws below error any idea what is implemented wrong here its expecting error >
v1Transform.js
module.exports = async (req, res) => {
try {
const validateResponse = responseHandler(req.drugPriceResponse);
} catch (error) {
if (error instanceof AppError) {
res.status(error.response.status).send(error.response.payload);
} else {
res.status(500).send(defaultErrorResponse);
}
}
}
main.test.js
describe('v1Transform()', () => {
it('should return error if accounts are ommitted', () => {
try {
v1Transform(req);
} catch (error) {
expect(error.response).to.deep.equal({
status: 500,
payload: {
'status': 500,
'title': 'Internal Server Error',
'detail': 'Accounts are not valid'
}
});
}
});
});
Error
1) v1Transform()
should return error if prices are ommitted:
AssertionError: expected undefined to deeply equal { Object (status, payload) }
I would like to know how to send error code in promise as response in nodejs. Error in Promise Not sending any error in response object in NodeJS/Express
module.exports.providerData = function (reqUrl, query) {
return new Promise(async function (resolve, reject) {
try {
var validUrl = checkValidParamters(reqUrl, query);
if(validUrl != true){
throw new Error('failed');
}
else{
sendcountry = countryjson.filter(function (send) {
return send.country_name == param_sendcountry;
})
var provider_sendcncode = sendcountry[0].country_code;
var receive = countryjson.filter(function (pr) {
return pr.country_name == param_receivecountry;
})
var valid = true;
var valid_obj = { validstatus: valid};
resolve(valid_obj);
}
}
catch (err) {
reject(err);
}
});
}
in app.js
router.get('/', function (req, res, next) {
if (getcountries == null && getcurrencies == null && getproviders == null) {
util.providerData(req.originalUrl, req.query).then(obj => {
res.render("corridor.ejs");
}).catch(err=>{
res.status(401).send({ error : err.message });
})
}
else {
console.log('just return');
util.providerData(req.originalUrl, req.query).then(obj => {
res.render("corridor.ejs");
}).catch(err=>{
res.status(401).send({ error : err.message });
})
}
});
I need to catch the error response res.status(401).send({ error : err.message }); if export function is returning false/error
your promise doesn't resolve anything. to resolve, you just simple return your response.
router.get('/', function (req, res, next) {
if (getcountries == null && getcurrencies == null && getproviders == null) {
return util.providerData(req.originalUrl, req.query).then(obj => {
return res.render("corridor.ejs");
}).catch(err=>{
return res.status(401).send({ error : err.message });
})
}
else {
console.log('just return');
return util.providerData(req.originalUrl, req.query).then(obj => {
return res.render("corridor.ejs");
}).catch(err=>{
return res.status(401).send({ error : err.message });
})
}
});
I'm trying to rewrite a retry function with callbacks into a Bluebird promise one but can't seem to get my head around the correct way of doing this. At the bottom is the working callback function for retrying Azure DocumentDB when limit is met. I'm trying to use promises in the function itself but it returns before reaching the "Then". Any hints on how to tackle this or if performance is affected by using catch this way would be appreciated. Thank you!
"readDocRetry": function(id, retries) {
var self = this;
return new Promise(function(resolve, reject){
self.client.readDocumentAsync(self.docsLink + id, null, function(err, data){
if (err) {
reject(err);
} else {
resolve(data)
}
}).then(function(results) {
console.log("ReadDocRetry result: " + results)
return results;
}).catch(function(err, headers) {
RetryError(self, id, err, headers, retries);
});
});
}
function RetryError(self, id, err, headers, retries) {
if (err && err.code) {
if (err.code === 429 && retries >= 0) {
setTimeout(function() {
self.readDocRetry(id, retries - 1);
}, Number(headers['x-ms-retry-after-ms'] || 1));
}
else if (err.code === 503 && retries >= 0) {
setTimeout(function() {
self.readDocRetry(id, retries - 1)
}, 500);
}
}
else if(err) {
console.log(err);
}else{
console.log("Err missing in RetryError");
}
}
bbCtx.readDocRetry("19").then(function(res){
console.log("Hurrah!" + res);
})
------- Working example with traditional callbacks which I'm trying to make promise based -----
dbContext.prototype = {
readDocRetry: function (id, retries, cb) {
var self = this;
self.client.readDocument(self.docsLink + id, function (err, results, headers) {
if (err) {
if (err.code === 429 && retries >= 0) {
var aR = retries - 1;
setTimeout(function () {
self.readDocRetry(id, aR, cb);
}, Number(headers['x-ms-retry-after-ms'] || 1));
} else if (err && err.code === 503 && retries >= 0) {
var aR = retries - 1;
setTimeout(function () {
self.readDocRetry(id, aR, cb)
}, 500);
} else {
cb(err);
}
} else {
cb(null, results);
}
});
},
When your catch callback is supposed to handle anything, it will need to return that new result like every other promise callback. In your case, it could return the promise for the result of the retry attempt:
function readDocRetry(id, retries) {
var self = this;
return new Promise(function(resolve, reject){
self.client.readDocumentAsync(self.docsLink + id, null, function(err, data){
if (err) {
reject(err);
} else {
resolve(data)
}
});
}).then(function(results) {
console.log("ReadDocRetry result: " + results)
return results;
}).catch(function(err, headers) {
if (err && err.code) {
if (err.code === 429 && retries >= 0) {
return Promise.delay(headers['x-ms-retry-after-ms'] || 1).then(function() {
return self.readDocRetry(id, retries - 1);
});
} else if (err.code === 503 && retries >= 0) {
return Promise.delay(500).then(function() {
return self.readDocRetry(id, retries - 1)
});
}
}
if (err) {
console.log(err);
throw err;
} else {
console.log("Err missing in RetryError");
throw new Error("rejection without error");
}
});
}
I am following this tutorial http://www.angular-meteor.com/tutorials/socially/angular2/meteor-methods
so having :
import {Parties} from './parties';
function getContactEmail(user: Meteor.User): string {
if (user.emails && user.emails.length)
return user.emails[0].address;
return null;
};
Meteor.methods({
invite: function(partyId: string, userId: string) {
check(partyId, String);
check(userId, String);
let party = Parties.findOne(partyId);
if (!party)
throw new Meteor.Error('404', 'No such party!');
if (party.public)
throw new Meteor.Error('400', 'That party is public. No need to invite people.');
if (party.owner !== this.userId)
throw new Meteor.Error('403', 'No permissions!');
if (userId !== party.owner && (party.invited || []).indexOf(userId) == -1) {
Parties.update(partyId, { $addToSet: { invited: userId } });
let from = getContactEmail(Meteor.users.findOne(this.userId));
let to = getContactEmail(Meteor.users.findOne(userId));
if (Meteor.isServer && to) {
Email.send({
from: 'noreply#socially.com',
to: to,
replyTo: from || undefined,
subject: 'PARTY: ' + party.name,
text: `Hi, I just invited you to ${party.name} on Socially.
\n\nCome check it out: ${Meteor.absoluteUrl()}\n`
});
}
}
}
});
and
invite(user: Meteor.User) {
this.call('invite', this.party._id, user._id, (error) => {
if (error) {
alert(`Failed to invite due to ${error}`);
return;
}
alert('User successfully invited.');
});
}
I can't understand the (error) => {, From where does the error value come?
in ES6 (args) => { is shorthand way of defining a function read more
so
invite(user: Meteor.User) {
this.call('invite', this.party._id, user._id, (error) => {
if (error) {
alert(`Failed to invite due to ${error}`);
return;
}
alert('User successfully invited.');
});
}
would be the same as
invite(user: Meteor.User) {
this.call('invite', this.party._id, user._id, function(error){
if (error) {
alert(`Failed to invite due to ${error}`);
return;
}
alert('User successfully invited.');
});
}