feat: implement isProperFraction function with tests for main cases

Author: Tarawally

Sprint-3/1-implement-and-rewrite-tests/implement/2-is-proper-fraction.js

@@ -8,9 +8,12 @@
 // write one test at a time, and make it pass, build your solution up methodically
 
 function isProperFraction(numerator, denominator) {
-  if (numerator < denominator) {
-    return true;
-  }
+  // A proper fraction is defined as a fraction a/b where:
+  // 1. The numerator (a) is a positive integer
+  // 2. The denominator (b) is a positive integer
+  // 3. The absolute value of the numerator is less than the absolute value of the denominator:
+  //    |a| < |b|
+  return Math.abs(numerator) < Math.abs(denominator);
 }
 
 // The line below allows us to load the isProperFraction function into tests in other files.
@@ -46,14 +49,22 @@ assertEquals(improperFraction, false);
 // 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.
 const negativeFraction = isProperFraction(-4, 7);
-// ====> complete with your assertion
+assertEquals(negativeFraction, 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.
 const equalFraction = isProperFraction(3, 3);
-// ====> complete with your assertion
+assertEquals(equalFraction, false);
 
 // Stretch:
 // What other scenarios could you test for?
+
+// Given the definition of a proper fraction, cases involving values such as zero or floating-point numbers should be considered false as they are not positive integers (natural numbers):
+// - Where either the numerator or denominator is zero, the function should return false.
+// - Floating-point numbers in the function should return false, as proper fractions are defined for integers only.
+
+// The method `Number.isInteger()` can be used to check for positive integers by:
+// - Using `Math.abs()` to handle negative values when comparing numerator and denominator.
+// - Then checking if both numerator and denominator are positive integers using `Number.isInteger()` and greater than zero.