remove 'TODO' comments

Removed TODO comment and added a test case for zero denominator.

Author: vmoratti

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

@@ -2,7 +2,6 @@
 // We will use the same function, but write tests for it using Jest in this file.
 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: denominator is zero
 test(`should return false when denominator is zero`, () => {
@@ -62,4 +61,4 @@ test(`should return true when numerator and denominator are both floating point
 // numerator and denominator are both floating point numbers, numerator is larger
 test(`should return false when numerator and denominator are both floating point numbers and numerator is larger`, () => {
   expect(isProperFraction(2.5, 1.5)).toEqual(false);
-});
+});