Express : unable to load the intended path with middlewares - node.js

Question

i am beginer with Express and I have a rather strange functionality that I am achieving with the middlewares. Here I call a URL which is fetched by its middleware and then on next() another middleware gets called. now in the next() of the second middleware I need to load the component, but issue is that, URL is not changing after the first middleware's next().
Code :
Express App : Router :
app.use('/common/global/login', mainHandler);
app.use('/common/*', subhandler, SuccessComponent);
Middleware :
export function mainHandler(req, res, next) {
const global-url= "someURL"
if (global-url) {
return fetch(global-url)
.then((response) => response.json())
.then((response) => {
if (response.data) {
next();
} else {
throw Error(response.statusText);
}
})
.catch((error) => {
res.redirect('/session-expired');
next(error);
});
}
res.redirect('/session-expired');
}
export function subhandler (req, res, next) {
const other_url= "someOtherURL"
return fetch(other_url)
.then((response) => response.json())
.then((response) => {
if (response.data) {
// here it not loading the SUCCESSCOMPONENT as the URL still remains /common/global/login
return next();
}
throw Error(response.statusText);
})
.catch((error) => {
next(error);
res.redirect('/session-expired');
});
}
res.redirect('/session-expired');
}

Answer 1

You have a syntax error with your code, it may be worth fixing this first to see if it is contributing to the error you are having:
export function mainHandler(req, res, next) {
const global-url= "someURL"
if (global-url) {
return fetch(global-url)
...
You cannot define a variable that contains a hyphen -, as this read as the subtract operator.
const global-url = ... , should be const global_url = ...
And of course update all instances where you are calling this variable.
In your code's current state, next() is not being called by the first middleware because if (global-url) {...} would not return a thruthy value therefore not triggering the next middleware in the chain.
Try:
export function mainHandler(req, res, next) {
const global_url= "someURL"
if (global_url) {
return fetch(global_url)
.then((response) => response.json())
.then((response) => {
if (response.data) {
next();
} else {
throw Error(response.statusText);
}
})
.catch((error) => {
res.redirect('/session-expired');
next(error);
});
}
res.redirect('/session-expired');
// Note that if this 'if' is not satisfied, 'next()' is not called.
}