test: expand isProperFraction tests to cover all edge cases and scenarios

Author: Grajales-K

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

@@ -4,7 +4,26 @@ const isProperFraction = require("../implement/2-is-proper-fraction");
 
 // TODO: Write tests in Jest syntax to cover all combinations of positives, negatives, zeros, and other categories.
 
-// Special case: numerator is zero
-test(`should return false when denominator is zero`, () => {
-  expect(isProperFraction(1, 0)).toEqual(false);
+// test: proper fraction
+// --- case 1: Proper Fractions ---
+test('should return true for valid proper fractions, including negative numbers', () => {
+  expect(isProperFraction(5, 9)).toBe(true);
+  expect(isProperFraction(3, 4)).toBe(true);
+  expect(isProperFraction(2, 8)).toBe(true);
+  expect(isProperFraction(1, 6)).toBe(true);
+  expect(isProperFraction(-3, -5)).toBe(true);
 });
+
+// --- case 2: Improper Fractions ---
+test('should return false for improper fractions where numerator >= denominator', () => {
+  expect(isProperFraction(-7, 5)).toBe(false);
+  expect(isProperFraction(10, 3)).toBe(false);
+  expect(isProperFraction(5, 5)).toBe(false); 
+});
+
+// --- case 3: 0 Numerator and 0 Denominator ---
+test('should return false when numerator or denominator is zero', () => {
+  expect(isProperFraction(3, 0)).toBe(false); 
+  expect(isProperFraction(0, 3)).toBe(false); 
+  expect(isProperFraction(0, 0)).toBe(false); 
+});