Module-Structuring-and-Testing-Data/Sprint-3/1-implement-and-rewrite-tests/rewrite-tests-with-jest/2-is-proper-fraction.test.js at 4ea82f44d6659a4ff998cbbe7014430e1e46e7f5 · CodeYourFuture/Module-Structuring-and-Testing-Data · GitHub

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// This statement loads the isProperFraction function you wrote in the implement directory.
// 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: numerator is zero
test(`should return false when denominator is zero`, () => {
  expect(isProperFraction(1, 0)).toEqual(false);
});

test(`should return true in normal cases where numerator < denominator`, () => {
  expect(isProperFraction(1, 2)).toEqual(true);
});

test(`should return false when numerator >= denominator`, () => {
  expect(isProperFraction(2, 1)).toEqual(false);
  expect(isProperFraction(2, 2)).toEqual(false);
});

test('should return true when numerator is negative and denominator is positive', () => {
  expect(isProperFraction(-1, 2)).toEqual(true);
  expect(isProperFraction(-2, 1)).toEqual(true);
  expect(isProperFraction(-2, 2)).toEqual(true)

});

test(`should return false when numerator is positive and denominator is negative`, () => {
  expect(isProperFraction(1, -2)).toEqual(false);
  expect(isProperFraction(2, -1)).toEqual(false);

});

test(`should return false when numerator and denominator are both negative`, () => {
  expect(isProperFraction(-1, -2)).toEqual(false);
  expect(isProperFraction(-2, -1)).toEqual(false);
  expect(isProperFraction(-2, -2)).toEqual(false);
});

test(`should return true when numerator is zero and denominator is positive`, () => {
  expect(isProperFraction(0, 1)).toEqual(true);
  expect(isProperFraction(0, 2)).toEqual(true);

});

test(`should return false when numerator is zero and denominator is negative`, () => {
  expect(isProperFraction(0, -1)).toEqual(false);
  expect(isProperFraction(0, -2)).toEqual(false);

});