Theme
Primary Color
Lesson 5

Jest Global Methods – Test Part 2

sum.js
const theSum = (...numbers) => numbers.reduce((pv, cv) => pv + cv, 0);

module.exports = theSum;
sum.test.js
const theSum = require("../sum");

/*
  test(name, fn, timeout)
  it(name, fn, timeout)
*/

test("Return 0 If No Number", () => {
  expect(theSum()).toBe(0);
});

test("Return The Number", () => {
  expect(theSum(10)).toBe(10);
});

test("Return The Number 1 + Number 2", () => {
  expect(theSum(15, 25)).toBe(40);
});

test("Return The Number 1 + Number 2 + Number 3", () => {
  expect(theSum(10, 20, 30)).toBe(60);
});

test("Return The Number 1 + Number 2 + Number 3 + Number 4", () => {
  expect(theSum(10, 20, 30, 10)).toBe(70);
});

test("Return The Sum Result Of All Numbers", () => {
  expect(theSum(1, 9, 10, 40, 20, 10, 100, 10)).toBe(200);
});

console.log([].reduce((a, b) => a + b, 0));