is-proper-fraction.test.js

// You wil need to implement a function isProperFraction
// You need to write assertions for your function to check it works in different cases

const { log } = require("console");
const { default: expect } = require("expect");

// Terms:
// Fractions: https://www.bbc.co.uk/bitesize/topics/zt9n6g8/articles/zjxpp4j
// Written here like this: 1/2 == Numerator/Denominator

// Acceptance criteria:

// Proper Fraction check:
// Input: numerator = 2, denominator = 3
// target output: true
// Explanation: The fraction 2/3 is a proper fraction, where the numerator is less than the denominator. The function should return true.

// Improper Fraction check:
// Input: numerator = 5, denominator = 2
// target output: false
// Explanation: The fraction 5/2 is an improper fraction, where the numerator is greater than or equal to the denominator. The function should return false.

// Zero Denominator check:
// Input: numerator = 3, denominator = 0
// No target output: Error (Denominator cannot be zero)
// Explanation: The function should throw an error when the denominator is zero, as it's not a valid fraction.

// Negative Fraction check:
// Input: numerator = -4, denominator = 7
// target output: true
// Explanation: The fraction -4/7 is a proper fraction because the absolute value of the numerator (4) is less than the denominator (7). The function should return true.

// Equal Numerator and Denominator check:
// Input: numerator = 3, denominator = 3
// target output: false
// Explanation: The fraction 3/3 is not a proper fraction because the numerator is equal to the denominator. The function should return false.

// These acceptance criteria cover a range of scenarios to ensure that the isProperFraction function handles both proper and improper fractions correctly and handles potential errors such as a zero denominator.

function isProperFraction(a, b) {
  if (b === 0) {
    return "error";
  }
  if (a === b) {
    return false;
  }
  if (a < b) {
    return true;
  }
  if (a > b) {
    return false;
  }
  if (a < 0) {
    return true;
  }
}

test("Check if the fraction is a proper fraction or not ", function () {
    
    expect(isProperFraction(4, 7)).toBe(true);
    expect(isProperFraction(7, 7)).toBe(false);
    expect(isProperFraction(-4, 7)).toBe(true);
    expect(isProperFraction(4, 0)).toBe("error");
    expect(isProperFraction(5, 2)).toBe(false);
});