React-Native JSON Parse error: Unexpected identifier "var" - json

Question

Im trying to make a login screen for my react-native app, but when I try to login I get the error message 'JSON Parse error: unexpected token "var" ' displayed.
I have a react native app and a server app in a different folder which I acces via localhost.
I have tried to change var to let to see what would happen, but then I would get the same error, but with let instead.
This is my react-native code
login = () => {
fetch('http://192.168.0.105:8888/loginbackend/routes/users.js', {
method: 'POST',
header: {
'Content-Type': 'application/json',
'Accept': 'application/json',
},
body: JSON.stringify({
username: this.state.username,
password: this.state.password,
})
})
.then((response) => response.json())
.then ((res) => {
if (res.success === true) {
AsyncStorage.setItem('user', res.user);
this.props.navigation.navigate('Profile');
}
else {
alert(res.message);
}
})
.done();
}
}
My server file
var express = require('express');
var router = express.Router();
var mysql = require('mysql');
var connection = mysql.createConnection({
host: 'localhost',
user: 'root',
password: 'root',
database: 'users'
});
router.POST('/', function(req, res) {
var username = req.body.username;
var password = req.body.password;
connection.query(
"SELECT * FROM user WHERE username = ? AND password = ?",
[username, password], function (err, row){
if (err) {
console.log(err);
res.send({ 'success': false, 'message': 'Kan niet met de database verbinden'});
}
if (row.length > 0 ){
res.send({ 'success': true, 'user': row[0].username });
} else {
res.send({ 'success': false, 'message': 'Gebruiker niet gevonden'});
}
});
});
module.exports = router;
Before, I got JSON Parse error: unexpected token '<', but now its JSON Parse error: unexpected identifier "var". I cant login and cant get an alert if the credentials are incorrect.

Answer 1

Express wasnt set up correctly and in my app file i had 'header' changed that to 'headers'.
app file
login = () => {
fetch('http://localhost:8080/users/', {
method: 'POST',
headers: {
'Content-Type': 'application/json',
'Accept': 'application/json',
},
body: JSON.stringify({
"username": this.state.username,
"password": this.state.password,
})
})
.then((response) => response.json())
.then ((res) => {
if (res.success === true) {
AsyncStorage.setItem('user', res.user);
this.props.navigation.navigate('Profile');
}
else {
alert(res.message);
}
})
.done();
}
}
express file App.js
const port = 8080;
var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');
var bodyParser = require('body-parser');
var mysql = require('mysql');
var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');
app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', indexRouter);
app.use('/users', usersRouter);
// catch 404 and forward to error handler
app.use(function(req, res, next) {
next(createError(404));
});
// error handler
app.use(function(err, req, res, next) {
// set locals, only providing error in development
res.locals.message = err.message;
res.locals.error = req.app.get('env') === 'development' ? err : {};
// render the error page
res.status(err.status || 500);
res.render('error');
});
app.listen(port, () => console.log(`Backend now listening on ${port}!`));
module.exports = app;
express users.js
var express = require('express');
var router = express.Router();
var mysql = require('mysql');
var connection = mysql.createConnection({
host: '127.0.0.1',
user: 'root',
password: 'root',
database: 'users',
port: 8889
});
router.post('/', function(req, res) {
var username = req.body.username;
var password = req.body.password;
connection.query(
"SELECT * FROM user WHERE username = ? AND password = ?",
[username, password], function (err, row){
if (err) {
console.log(err);
res.send({ 'success': false, 'message': 'Kan niet met de database verbinden'});
}
if (row.length > 0 ){
res.send({ 'success': true, 'user': row[0].username });
} else {
res.send({ 'success': false, 'message': 'Gebruiker niet gevonden'});
}
});
});
module.exports = router;
Hope this helps for people who are stuck on the same thing.