NodeJs : TypeError: require(...) is not a function

For me, when I do Immediately invoked function, I need to put ; at the end of require().

Error:

const fs = require('fs')

(() => {
  console.log('wow')
})()

Good:

const fs = require('fs');

(() => {
  console.log('wow')
})()

I think this means that module.exports in your ./app/routes module is not assigned to be a function so therefore require('./app/routes') does not resolve to a function so therefore, you cannot call it as a function like this require('./app/routes')(app, passport).

Show us ./app/routes if you want us to comment further on that.

It should look something like this;

module.exports = function(app, passport) {
    // code here
}

You are exporting a function that can then be called like require('./app/routes')(app, passport).

---

One other reason a similar error could occur is if you have a circular module dependency where module A is trying to require(B) and module B is trying to require(A). When this happens, it will be detected by the require() sub-system and one of them will come back as null and thus trying to call that as a function will not work. The fix in that case is to remove the circular dependency, usually by breaking common code into a third module that both can separately load though the specifics of fixing a circular dependency are unique for each situation.

Remember to export your routes.js.

In routes.js, write your routes and all your code in this function module:

exports = function(app, passport) {

/* write here your code */ 

}

For me, this was an issue with cyclic dependencies.

IOW, module A required module B, and module B required module A.

So in module B, require('./A') is an empty object rather than a function.

How to deal with cyclic dependencies in Node.js