Node TypeError: Promise resolver #<Promise> is not a function

Question

I'm getting a type error on the promise I'm trying to use around the first reject, but from what I can tell it looks like the examples I've found. What am I doing wrong?

var resolve, reject;
exports.handler = (event, context, callback) =>
{

	//var filePromise = new Promise(ProcessFile(resolve, reject));



	var filePromise = new Promise(function ProcessFile()
	{
		console.log("Processing file");
		return new Promise((resolve, reject) => {
		var array;

		if(array.length <0)
		{
			resolve("We have stuff in the array, looks promising");
		}
		else
		{
			reject("Something went wrong populating the array");
		}

		});
	});

	filePromise.then(CheckHeaders());

	function CheckHeaders()
	{
		return new Promise((resolve, reject) =>
		{
			console.log("Checking headers");
			
			reject("Unauthorised");
		});	//close promise
	 }	//close function
};

Answer 1

You only need one promise.

var filePromise = new Promise(function(resolve, reject) {
  console.log("Processing file");
  var array = [1];

  if (array.length > 0) {
    resolve("We have stuff in the array, looks promising");
  } else {
    reject("Something went wrong populating the array");
  }
});

function CheckHeaders() {
  return new Promise((resolve, reject) => {
    console.log("Checking headers");

    reject("Unauthorised");
  }); //close promise
}

filePromise
  .then(res => {
    console.log(res)
    CheckHeaders()
      .then(res2 => console.log(res2))
  }).catch(err => console.warn(err));

As @Bergi pointed out it would be better to only have one overall promise.

var filePromise = new Promise(function(resolve, reject) {
  console.log("Processing file");
  var array = [1];

  if (array.length > 0) {
    resolve("We have stuff in the array, looks promising");
  } else {
    reject("Something went wrong populating the array");
  }

  //here check headers
  reject("Unauthorised");


});

filePromise
  .then(res => {
    console.log(res)
  }).catch(err => console.warn(err));