is-proper-fraction.js

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

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

function isProperFraction(numerator, denominator) {
  const fraction = numerator / denominator;
  if (denominator === 0) {
    return "Error (Denominator cannot be zero)";
  } else if (
    (fraction < 1 && fraction > 0) ||
    (fraction > -1 && fraction < 0)
  ) {
    return true;
  } else {
    return false;
  }
}

// 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.
console.assert(
  isProperFraction(2, 3) === true,
  "proper fraction check failed, input 2, 3"
);
// 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.
console.assert(
  isProperFraction(5, 2) === false,
  "improper fraction check failed, input 5, 2"
);
// 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.
console.assert(
  isProperFraction(3, 0) === "Error (Denominator cannot be zero)",
  "zero dominator check failed, input 3, 0"
);
// 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.
console.assert(
  isProperFraction(-4, 7) === true,
  "negative fraction check failed, input -4, 7"
);
// 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.
console.assert(
  isProperFraction(3, 3) === false,
  "equal numerator and denominator check failed, input 3, 3"
);
// 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.