I am getting this error:
UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): Error: Can't set headers after they are sent.
from this portion of my express route route:
router.post('/', jsonParser, (req, res) => {
// checking that given id is valid
let { id } = req.body;
User.findById({ id })
.count()
.then(count => {
if (count < 1) {
return Promise.reject({
code: 422,
reason: 'Validation Error',
message: 'Family must be created by a user',
location: 'id'
})
}
return resolve();
})
.catch(err => {
return res.status(err.code).json({code: err.code, message: err.message, reason: err.reason, location: err.location })
});
...
I'm not stellar at promises. Can someone see what I am doing incorrectly here?
resolve is undefined, you could use return count instead, to pass data to the next promise:
User.findById({ id })
.count()
.then(count => {
if (count < 1) {
throw new Error('Family must be created by a user')
}
// success
return count;
})
.then( res => { // res will be count if the promise not rejected
res.json({ success: true, count: res })
})
.catch(err => {
return res.status(422).json({
code: 422,
reason: 'Validation Error',
message: 'Family must be created by a user',
location: 'id'
})
});
.catch(err => { return res.status(err.code).json({code: err.code, message: err.message, reason: err.reason, location: err.location }) });
Here lies the issue. when a response is sent you can not send another response. So when you do
res.status(), express sends the response with status code. and .json() will give exception.
try setting status like this.
res.statusCode = code; and then
res.json()
Related
In my social media application, when a user comments on a post, it throws a 500 Internal Server Error.
The console states POST https://shielded-journey-88539.herokuapp.com/https://us-central1-myapp-1d191.cloudfunctions.net/api/post/3Y7OcHJXXXa0ilBeq35u/comment 500 (Internal Server Error)
When I check the commentOnPost route on Postman, the response returns a Status 200, but the body returns Invalid Host Header.
// Comment on a Post API
exports.commentOnPost = (req, res) => {
if (req.body.body.trim() === '') {
return res.status(400).json({ comment: 'Cannot be empty' });
}
const newComment = {
body: req.body.body,
createdAt: new Date().toISOString(),
postId: req.params.postId,
userHandle: req.user.handle,
profileImage: req.user.profileImage
};
db.doc(`/posts/${req.params.postId}`)
.get()
.then(doc => {
if (!doc.exists) {
return res.status(404).json({ error: 'Post does not exist.' });
}
// after gaining access to document, use prefix reference to update comment count
return doc.ref.update({ commentCount: doc.data().commentCount + 1 })
})
.then(() => { // add newComment to comments collection
return db.collection('comments').add(newComment);
})
.then(() => {
res.json(newComment);
})
.catch(err => {
console.log(err);
res.status(500).json({ error: 'Something went wrong' });
});
};
When I console.log(commentData) inside of dataSlice/submitComment, it returns just the req.body.body and not the rest of the newComment object, from the commentOnPost route.
// submitComment of dataSlice
export const submitComment = (postId, commentData) => dispatch => {
console.log(commentData)
return axios
.post(`/post/${postId}/comment`, commentData)
.then(res => {
dispatch(submitTheComment(res.data))
dispatch(clearErrors());
})
.catch(err => dispatch(setErrors(err.response)))
};
I'm using my own Heroku proxy server.
// App.jsx
axios.defaults.baseURL =
'https://shielded-journey-88539.herokuapp.com/https://us-central1-myapp-1d191.cloudfunctions.net/api';
// package.json
"proxy": "https://shielded-journey-88539.herokuapp.com/https://us-central1-myapp-1d191.cloudfunctions.net/api"
What am I doing wrong?
Can you try this code, and console.log(commentData), and where is commentData?
exports.commentOnPost = (req, res) => {
if (req.body.body.trim() === '') {
return res.status(400).json({ comment: 'Cannot be empty' });
}
const newComment = {
body: req.body.body,
createdAt: new Date().toISOString(),
postId: req.params.postId,
userHandle: req.user.handle,
profileImage: req.user.profileImage
};
console.log("newComment: ", newComment)
db.doc(`/posts/${req.params.postId}`).get()
.then(doc => {
if (!doc.exists) {
return res.status(404).json({ error: 'Post does not exist.' });
}
// after gaining access to document, use prefix reference to update comment count
return doc.ref.update({ commentCount: doc.data().commentCount + 1 });
}).then(() => {
// add newComment to comments collection
db.collection('comments').add(newComment);
res.status(200).json(newComment);
}).catch(err => {
console.log("Error in Catch commentOnPost: ", err);
res.status(500).json({ error: 'Something went wrong' });
});
};
I am sending an HTTP request from angular to a node/express API. How do I get the actual error message I send from the node/express API
I am handling my exceptions well when they are thrown in the API but the moment I try to read the message in Angular I only get the name of the type of error I throw. For example, if I throw a 409 the error received by angular is just "Conflict" and does not contain the details I send. Please look at my code below.
I am sending my request as below
register(user: UserAccount) {
return this.http
.post(`${config.apiUrl}/users/register`, user)
.pipe(
map((res: HttpResponse<Response>) => {
return res;
}))
.pipe(catchError(err => this.errorHandler.handleError(err)));
}
My handle error is as below:
handleError(error: HttpErrorResponse) {
console.log(error);
if (error) {
let errMessage = '';
try {
errMessage = error.message;
} catch (error) {
errMessage = error.statusText;
}
return throwError(errMessage || error || 'Server error');
}
return throwError(error.error || error || 'Server error');
}
This how I am throwing my error when I occurs in my Node/Express API
registerUser (req, res) {
debug(chalk.blue(`*** insert user`))
userRepo
.create(req.body)
.then(user => {
debug(chalk.green(`*** Insert User ok!`))
res.status(200).json({
status: true,
error: null,
user: user
})
})
.catch(err => {
debug(chalk.red(`*** insertUser error: ${util.inspect(err)}`))
if (err['type'] && err['type'] === '409') {
res.status(409).json({
status: false,
error: err['message'],
user: null
})
} else {
res.status(400).json({
status: false,
error: err,
user: null
})
}
})
}
I want to be able to receive the json object with the information about the error but all I am getting when I access the error item is, for example, in the case of raising a 409, I only get 'Conflict'
The reason for this is that when you catch the error and the status is a 409, you return `err['message'] instead of 'err'.
So instead of:
res.status(409).json({
status: false,
error: err['message'],
user: null
})
You should return:
res.status(409).json({
status: false,
error: err,
user: null
})
This is actually what you do in the case of a 400 error!
My REST API reasons this: {"error":"Auth failed. User does not exist"}.
I try save this error to my state using setState in React, but I have a this error: Cannot read property 'error' of undefined. What's the problem?
export const login = user =>
axios
.post('http://localhost:3000/api/users/login', {
login: user.login,
password: user.password,
})
.then(res => {
localStorage.setItem('userToken', res.data.token);
return res.data.token;
})
.catch(err => {
console.log(err);
});
Function in React.js:
onSubmit(e) {
e.preventDefault();
const user = {
login: this.state.login,
password: this.state.password,
};
login(user).then(res => {
if (!res.error) { // <- this error: TypeError: Cannot read property 'error' of undefined
this.props.history.push(`/dashboard`);
} else {
this.setState({ error: res.error });
}
});
}
This is my backend code:
// Login Action
...
return res.status(200).json({
message: 'Auth successful',
token,
});
}
res
.status(400)
.json({ error: 'Auth failed. The password is incorrect.' });
} else {
res.status(400).json({ error: 'Auth failed. User does not exist' });
}
})
.catch(err => {
res.status(400).json({ error: err });
});
};
Try this:
login(user).then(() => this.props.history.push(`/dashboard`))
.catch(error=>this.setState({ error })
But maybe there is another problem, you cannot normally push to state the way you do for immutability concern. I guess you know, but I post in case:
this.setState({ history: [...this.state.history, `/dashboard`] })
since your backend is returning a response with 400 status code, you have to handle that in the catch block of your login function. right now you are writing the error into the console and not returning anything, that is why your login response is undefined in your React code and you are getting that error.
to fix this, change the catch block of your login function so it looks something like this
.catch(err => {
console.log(err);
return {error:err};
});
Try this;
export const login = user =>
axios
.post('http://localhost:3000/api/users/login', {
login: user.login,
password: user.password,
})
.then(res => {
localStorage.setItem('userToken', res.data.token);
})
.then(() => return localStorage.getItem('userToken');)
.catch(err => {
console.log(err);
});
I keep getting "Can't set headers after they are sent" building a Node/Express API.
The issue is I am not setting the headers after the response has been sent anywhere. I am always calling res.status(xxx).json({}) to close ever condition.
Route
const router = require('express').Router();
router.get('/password/validate/:hash', PasswordController.validate);
router.post('/password/update', PasswordController.update);
Controller
This is where the error is occurring. I am calling the validate request specifically.
// Import node packages
const mongoose = require('mongoose');
const Password = require('../models/password');
const User = require('../models/user');
const bcrypt = require('bcryptjs');
const moment = require('moment');
const string = require('../middleware/string_functions')
exports.update = (req, res, next) => {
User.findOne({ email: req.body.email })
.exec()
.then(user => {
if (!user) {
res.status(401).json({
message: 'Cannot retrieve account'
})
}
const expiry = moment().add(30, 'seconds');
const unique_string = string.generate_random(32);
const url_hash = string.base64_encode(unique_string +':'+ user._id);
bcrypt.hash(unique_string, 10, (err, hash) => {
if (err) {
res.status(500).json({
error: err.message
})
}
const query = { user_id: user._id }
const newData = {
hash,
expiry
}
Password.findOneAndUpdate(query, newData, { upsert: true, new: true })
.exec()
.then(request => {
res.status(201).json({
message: 'success',
url: 'localhost:8081/users/password/validate/' + url_hash,
data: request
})
})
.catch(err => {
res.status(500).json({
error: err.message
})
})
})
})
.catch(err => {
res.status(500).json({
error: err.message
})
})
}
exports.validate = (req, res, next) => {
if (!req.params.hash) {
res.status(500).json({
error: 'Missing hash'
})
}
const data = string.base64_decode(req.params.hash).split(':');
console.log(data)
Password.findOne({ user_id: data[1] })
.exec()
.then(request => {
if (!request) {
res.status(404).json({
message: 'Change request not found or expired'
})
}
bcrypt.compare( data[0], request.hash, (err, result) => {
if (err) {
res.status(500).json({
error: err.message
})
}
if (result) {
if (moment().isAfter(request.expiry)) {
res.status(401).json({
message: 'Time has expired'
})
}
res.status(200).json({
message: 'Hash validation successful'
})
}
res.status(500).json({
error: 'Something went wrong'
})
})
})
.catch(err => {
res.status(500).json({
error: err.message
})
})
}
Console Error
_http_outgoing.js:494
throw new Error('Can\'t set headers after they are sent.');
^
Error: Can't set headers after they are sent.
at validateHeader (_http_outgoing.js:494:11)
at ServerResponse.setHeader (_http_outgoing.js:501:3)
at ServerResponse.header (/Users/chrislloyd/Development/Projects/happy-hour-api/node_modules/express/lib/response.js:767:10)
at ServerResponse.send (/Users/chrislloyd/Development/Projects/happy-hour-api/node_modules/express/lib/response.js:170:12)
at ServerResponse.json (/Users/chrislloyd/Development/Projects/happy-hour-api/node_modules/express/lib/response.js:267:15)
at bcrypt.compare (/Users/chrislloyd/Development/Projects/happy-hour-api/api/controllers/passwords.js:83:22)
at /Users/chrislloyd/Development/Projects/happy-hour-api/node_modules/bcryptjs/dist/bcrypt.js:297:21
at /Users/chrislloyd/Development/Projects/happy-hour-api/node_modules/bcryptjs/dist/bcrypt.js:1353:21
at Immediate.next [as _onImmediate] (/Users/chrislloyd/Development/Projects/happy-hour-api/node_modules/bcryptjs/dist/bcrypt.js:1233:21)
at runCallback (timers.js:789:20)
at tryOnImmediate (timers.js:751:5)
at processImmediate [as _immediateCallback] (timers.js:722:5)
Updated Example
exports.update = (req, res, next) => {
// Check if hash value exists
if (!req.params.hash) {
res.status(500).json({
error: 'Missing hash value'
});
return;
}
// Check if password and confirmation are the same
if (req.body.password != req.body.passwordConfirmation) {
res.status(401).json({
message: 'Password confirmation does not match'
});
return;
}
// Decode and split hash and user id into array
const data = string.base64_decode(req.params.hash).split(':');
// Find record that contains user id
Password.findOne({ user_id: data[1] })
.exec()
.then(request => {
console.log(request)
// Throw 404 error if record is not found
if (!request) {
return res.status(404).json({
message: 'Password change request doest not exist or timed out'
});
}
// Check if change request has expired
if (moment().isAfter(request.expiry)) {
res.status(401).json({
message: 'Password change request expired',
request: {
request: 'http://localhost:3001/users/password/request'
}
});
// Delete expired record
Password.remove({ _id: request._id })
.exec()
.catch(err => {
res.status(500).json({
error: err.message
});
});
return;
}
// Compare hash value from encoded string to encrypted hash value in database
console.log(mongoose.Types.ObjectId(request.user_id))
bcrypt.compare( data[0], request.hash, (err, result) => {
// Bcrypt error performing comparison
if (err) {
res.status(500).json({
error: err.message
});
return;
}
// Check if result is true
if (result) {
// Find user record matching request.user_id and update password
User.findOneAndUpdate({ _id: mongoose.Types.ObjectId(request.user_id) }, {$set: { password: req.body.password }}, {new: true}, (err, user) => {
console.log(user)
// Error finding and updating user record
if (err) {
res.status(500).json({
error: err.message
});
return;
}
// If returned user account is not null
if (user) {
res.status(200).json({
message: 'Password updated',
user
});
return;
}
// Could not find user record
res.status(404).json({
message: 'Could not find user account to update'
});
return;
})
}
// Catch all error
res.status(500).json({
error: 'Something went wrong'
});
return;
})
})
.catch(err => {
res.status(500).json({
error: err.message
});
return;
});
}
That particular error is caused when you send multiple responses to the same request.
You see to be thinking that as soon as you do res.status(...).json(...) that your function returns and stops executing. It does not. res.json() is just a regular function call. It doesn't change the control flow in your function at all (unless it throws an exception). A successful call to res.json() executes and then your function just keeps right on executing the lines of code that follow.
What you need is a return statement after each time you send a response (if there is any other code in your function that could execute and send another response) so that your function doesn't continue to execute and send another response or you could bracket your responses in if/else statements so you don't execute the sending of more than one response.
Here's a fixed version with 5 added return statements to keep the rest of your code from executing after you've sent a response and to keep you from sending multiple responses to the same request. Each addition is commented with ==> added:
// Import node packages
const mongoose = require('mongoose');
const Password = require('../models/password');
const User = require('../models/user');
const bcrypt = require('bcryptjs');
const moment = require('moment');
const string = require('../middleware/string_functions')
exports.update = (req, res, next) => {
User.findOne({ email: req.body.email })
.exec()
.then(user => {
if (!user) {
res.status(401).json({
message: 'Cannot retrieve account'
})
return; // <== added
}
const expiry = moment().add(30, 'seconds');
const unique_string = string.generate_random(32);
const url_hash = string.base64_encode(unique_string +':'+ user._id);
bcrypt.hash(unique_string, 10, (err, hash) => {
if (err) {
res.status(500).json({
error: err.message
})
return; // <== added
}
const query = { user_id: user._id }
const newData = {
hash,
expiry
}
Password.findOneAndUpdate(query, newData, { upsert: true, new: true })
.exec()
.then(request => {
res.status(201).json({
message: 'success',
url: 'localhost:8081/users/password/validate/' + url_hash,
data: request
})
})
.catch(err => {
res.status(500).json({
error: err.message
})
})
})
})
.catch(err => {
res.status(500).json({
error: err.message
})
})
}
exports.validate = (req, res, next) => {
if (!req.params.hash) {
res.status(500).json({
error: 'Missing hash'
})
}
const data = string.base64_decode(req.params.hash).split(':');
console.log(data)
Password.findOne({ user_id: data[1] })
.exec()
.then(request => {
if (!request) {
res.status(404).json({
message: 'Change request not found or expired'
})
return; // <== added
}
bcrypt.compare( data[0], request.hash, (err, result) => {
if (err) {
res.status(500).json({
error: err.message
})
return; // <== added
}
if (result) {
if (moment().isAfter(request.expiry)) {
res.status(401).json({
message: 'Time has expired'
})
}
res.status(200).json({
message: 'Hash validation successful'
})
return; // <== added
}
res.status(500).json({
error: 'Something went wrong'
})
})
})
.catch(err => {
res.status(500).json({
error: err.message
})
})
}
The res object by itself does not stop the execution of your program. You must use return if you prefer to use Guard Clauses instead of Nested Conditions
Replace statements like this:
if (err) {
res.status(500).json({
error: err.message
})
}
With this:
if (err) {
res.status(500).json({
error: err.message
});
return; // return statement added
}
I am new to node, and I have a simple situation, where I am posting to an endpoint on a node/express app. The issue is that I get:
POST /api/v2/user 500 25.378 ms - 54
(node:19024) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 2): Error: Can't set headers after they are sent.
(node:19024) DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
The relevant code that I have which is generating this is:
router.post('/', (req, res, next) => {
return authHelpers.createUser(req, res)
.then((user) => {
return localAuth.encodeToken(user[0]);
})
.then((token) => {
res.status(201).json({
status: 'success',
message: 'User Created',
token: token
});
})
.catch((err) => {
res.status(500).json({
status: 'error'
});
});
});
and then:
function createUser(req, res) {
return handleErrors(req)
.then(() => {
const salt = bcrypt.genSaltSync();
const hash = bcrypt.hashSync(req.body.password, salt);
return knex('users')
.insert({
email: req.body.email,
first_name: req.body.first_name,
last_name: req.body.last_name,
username: req.body.username,
password: hash
})
.returning('*');
})
.catch((err) => {
res.status(410).json({
status: err.message
});
});
}
function handleErrors(req) {
return new Promise((resolve, reject) => {
if (req.body.username.length < 6) {
reject({
message: 'Username must be longer than 6 characters'
});
} else if (req.body.password.length < 6) {
reject({
message: 'Password must be longer than 6 characters'
});
} else {
resolve();
}
});
}
I do know that if I remove the res.status(500).json({status: 'error'}); specifically, then the error goes away, but I am not sure if that is proper.
Any clue to what exactly is my error and how to fix?
You are trying to send response twice. First when catching the error
res.status(410).json({
status: err.message
});
And then after catch, promise chain continues the normal route until:
return localAuth.encodeToken(user[0]);
Which fails, because user is undefined and throws an exception.. so error handler is called and you are trying to send response again, but it fails because it has already been sent once
res.status(500).json({
status: 'error'
});
console log which error was thrown in the last part, I'm pretty sure it is something like
TypeError: Cannot read property '0' of undefined