Converting a common fraction to a periodic decimal?

Question

JavaScript

Good evening :)
Please help me with the translation of an ordinary fraction into a periodic decimal.
I use my methods of pairs - car, cdr. The result of addition of fractions does not suit because tests wait for record in the form of String.
Addition of fractions - pairs

export const sub = (pair, pair2) => (((car(pair) * (car(pair2)) + (cdr(pair) + cdr(pair2)))) / (cdr(pair) * car(pair2)));

toString is a fraction in a clear form:

export const toString = (pair) => (car(pair) + " / " + cdr(pair));

I want to make the addition method return a pair (numerator, denominator)

Answer 1

as an option use fraction.js

var f = new Fraction('88/33');
var c = f.toContinued(); // [2, 1, 2] в периоде 212212212212...

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