nextParamGenerator.js

function* makeFibonacciSequenceGenerator(endIndex = Infinity) {
    let previousNumber = 0;
    let currentNumber = 1;
    let skipCount = 0;
    
    for (let currentIndex = 0; currentIndex < endIndex; currentIndex++) {
        if (skipCount === 0) {
            skipCount = yield currentNumber; // skipCount is the parameter passed through the invocation of `fibonacciSequenceGenerator.next(value)` below.
            skipCount = skipCount === undefined ? 0 : skipCount; // makes sure that there is an input
        } else if (skipCount > 0){
            skipCount--;
        }
        
        let nextNumber = currentNumber + previousNumber;
        previousNumber = currentNumber;
        currentNumber = nextNumber;
    }
}

let fibonacciSequenceGenerator = makeFibonacciSequenceGenerator(50);

console.log(fibonacciSequenceGenerator.next().value);  // prints 1
console.log(fibonacciSequenceGenerator.next(3).value); // prints 5 since 1, 2, and 3 are skipped.
console.log(fibonacciSequenceGenerator.next().value);  // prints 8
console.log(fibonacciSequenceGenerator.next(1).value); // prints 21 since 13 is skipped.