Codesphere Jest demo javascript file and testing file

demo.js

//case sensitive palindrome check for strings
function isPalindrome(str) {
  const reversedString = reverseStr(str);
  return reversedString === str;
}

//function to reverse string
function reverseStr(str) {
  str = str.split("").reverse().join("");
  return str;
}

//exporting the functions to be tested
module.exports = { isPalindrome, reverseStr };

demo.test.js

const { isPalindrome, reverseStr } = require("./demo");

//checking if functiona are defined
test("Functions are defined", () => {
  expect(reverseStr).toBeDefined();
  expect(isPalindrome).toBeDefined();
});

//Checking reverseStr works properly
test("String reverses", () => {
  expect(reverseStr("Hello World")).toBe("dlroW olleH");
});

//Checking positive testcase for isPalindrome function
test("Palindorme returns true", () => {
  expect(isPalindrome("racecar")).toBeTruthy();
});

//Checking negative testcase for isPalindrome function
test("Palindorme returns false", () => {
  expect(isPalindrome("palindrome")).toBeFalsy();
});