a sample spec file for an isPalindrome function

is-palindrome.spec.ts

describe('isPalindrome', () => {
  describe('when provided a palindrome', () => {
    describe('consisting of letters', () => {
      it('should classify `"racecar"` as a palindrome');
      describe('ignoring case', () => {
        it('should classify `"Racecar"` as a palindrome');
      });
      describe('ignoring spaces', () => {
        it('should classify `"taco cat"` as a palindrome');
      });
      describe('ignoring spaces, case, and punctuation', () => {
        it('should classify `"Was it a car or a cat I saw?"` as a palindrome');
      });
    });
    describe('consisting of numbers', () => {
      it('should classify `"10801"` as a palindrome');
    });
    describe('consisting of symbols', () => {
      it('should classify `"@#$%$#@"` as a palindrome');
    });
  });
  describe('when provided a non-palindrome string value', () => {
    describe('consisting of letters', () => {
      it('should classify `"ice cream"` as not a palindrome');
    });
    describe('consisting of numbers', () => {
      it('should classify `"314"` as not a palindrome');
    });
    describe('consisting of symbols', () => {
      it('should classify `"!@#"` as not a palindrome');
    });
  });
  describe('when provided a non-string value', () => {
    it('should classify `null` as not a palindrome');
    it('should classify `undefined` as not a palindrome');
    it('should classify `{}` as not a palindrome');
    it('should classify `[]` as not a palindrome');
    it('should classify `true` as not a palindrome');
    it('should classify `false` as not a palindrome');
    it('should classify `NaN` as not a palindrome');
    it('should classify `0` as not a palindrome');
  });
});