/** Throws if argument passed is not a string
 * @param     String of characters
 * @returns   Count of unique characters. Case sensitive: A !== a
 */

function differentSymbolsNaive(str) {
   if (typeof str !== 'string') {
      throw new Error('Invalid input');
   }
   let uniqueChars = '';
   const { length } = str;
   for (let i = 0; i < length; i += 1) {
      if (!uniqueChars.includes(str[i])) {
         uniqueChars += str[i];
      }
   }
   return uniqueChars.length;
}

/* SOLUTION 2

function differentSymbolsNaive(str) {
   if (typeof str !== 'string') {
      throw new Error('Invalid input');
   }
   return new Set(str).size;
} 

*/

 /* SOLUION 3
 
function differentSymbolsNaive(str) {
   if (typeof str !== 'string') {
      throw new Error('Invalid input');
   }
   const uniqueChars = {};
   return str.split('').reduce((charCount, char) => {
      if (uniqueChars[char]) {
         return charCount;
      }
      uniqueChars[char] = char;
      return charCount + 1;
   }, 0);
}

*/

/**
* Test Suite 
*/
describe('differentSymbolsNaive()', () => {
    it('expects differentSymbolsNaive to be a function', () => {
        expect( typeof differentSymbolsNaive === 'function').toBe(true);
    });
    it('expects differentSymbolsNaive(true) to throw an error', () => {
        expect(() => differentSymbolsNaive(true)).toThrow(new Error('Invalid input'));
    });
    it('expects differentSymbolsNaive("cabca") to return 3', () => {
        expect(differentSymbolsNaive("cabca")).toBe(3);
    });
    it('expects differentSymbolsNaive("john.doe@gmail.com") to return 14', () => {
        expect(differentSymbolsNaive("john.doe@gmail.com")).toBe(14);
    });
    it('expects differentSymbolsNaive("https://www.scrimba.com?test=hoho") to return 18', () => {
        expect(differentSymbolsNaive("https://www.scrimba.com?test=hoho")).toBe(18);
    });
    it('expects differentSymbolsNaive("") to return 0', () => {
        expect(differentSymbolsNaive("")).toBe(0);
    });
    it('expects differentSymbolsNaive("javascriptmas is beau") to return 14', () => {
        expect(differentSymbolsNaive("javascriptmas is beau")).toBe(14);
    });
    it('expects differentSymbolsNaive("i\'m sexy and i know it ):") to return 14', () => {
        expect(differentSymbolsNaive("i'm sexy and i know it ):")).toBe(17);
    });
    it('expects differentSymbolsNaive("Arrrrrggggghhhhh") to return 4', () => {
        expect(differentSymbolsNaive("Arrrrrggggghhhhh")).toBe(4);
    });
    it('expects differentSymbolsNaive("AAAAaaaa") to return 2', () => {
        expect(differentSymbolsNaive("AAAAaaaa")).toBe(2);
    });
    it('expects differentSymbolsNaive("https://scrimba.com/scrim/co67445b3ab196c95ef8e7966") to return 24', () => {
        expect(differentSymbolsNaive("https://scrimba.com/scrim/co67445b3ab196c95ef8e7966")).toBe(24);
    });
});