Source for getting started with TDD article

final_function.js

const countWords = text => typeof text === 'string' && text.trim() ? text.match(/\S+\s{0,1}/g).length : 0;

full_tdd_test.js

const countWords = text => typeof text === 'string' && text.trim() ? text.match(/\S+\s{0,1}/g).length : 0;

describe('countWords()', () => {
  it('should handle empty text', () => {
    expect(countWords('')).toBe(0);
  });
  
  it('should handle one word text', () => {
    expect(countWords('nope')).toBe(1);
  });
  
  it('should handle n words text', () => {
    expect(countWords('tdd is fun bro')).toBe(4);
  });
  
  it('should handle text with trailing whitespaces', () => {
    expect(countWords(' so is skateboarding ')).toBe(3);
  });
  
  it('should handle text with uneven whitespaces separator', () => {
    expect(countWords(`  I'm 28, I love $#@! and    multi-spaces  `)).toBe(7);
  });
});

iteration_1_1.js

console.assert(countWords('') === 0, 'test 0: text is empty');

iteration_1_2.js

const countWords = () => {};
console.assert(countWords('') === 0, 'test 0: text is empty');

iteration_1_3.js

const countWords = text => text || 0;
console.assert(countWords('') === 0, 'test 0: text is empty');

iteration_2_1.js

const countWords = text => text || 0;
console.assert(countWords('') === 0, 'test 0: text is empty');
console.assert(countWords('nope') === 1, 'test 1: text contains 1 word');

iteration_2_2.js

const countWords = text => text ? text.split(' ').length : 0;
console.assert(countWords('') === 0, 'test 0: text is empty');
console.assert(countWords('nope') === 1, 'test 1: text contains 1 word');

iteration_3_1.js

const countWords = text => text ? text.split(' ').length : 0;
console.assert(countWords('') === 0, 'test 0: text is empty');
console.assert(countWords('nope') === 1, 'test 1: text contains 1 word');
console.assert(countWords('tdd is fun bro') === 4, 'test 2: text contains 4 words');

iteration_4_1.js

const countWords = text => text ? text.split(' ').length : 0;
console.assert(countWords('') === 0, 'test 0: text is empty');
console.assert(countWords('nope') === 1, 'test 1: text contains 1 word');
console.assert(countWords('tdd is fun bro') === 4, 'test 2: text contains 4 words');
console.assert(countWords(' so is skateboarding ') === 3, 'test 3: text contains 3 words');

iteration_4_2.js

const countWords = text => text ? text.trim().split(' ').length : 0;
console.assert(countWords('') === 0, 'test 0: text is empty');
console.assert(countWords('nope') === 1, 'test 1: text contains 1 word');
console.assert(countWords('tdd is fun bro') === 4, 'test 2: text contains 4 words');
console.assert(countWords(' so is skateboarding ') === 3, 'test 3: text contains 3 words');

iteration_5_1.js

const countWords = text => text ? text.trim().split(' ').length : 0;
console.assert(countWords('') === 0, 'test 0: text is empty');
console.assert(countWords('nope') === 1, 'test 1: text contains 1 word');
console.assert(countWords('tdd is fun bro') === 4, 'test 2: text contains 4 words');
console.assert(countWords(' so is skateboarding ') === 3, 'test 3: text contains 3 words');
console.assert(countWords(`  I'm 28, I love $#@! and    multi-spaces  `) === 7, 'test 4: text contains 7 words');

iteration_5_2.js

const countWords = text => text ? text.trim().replace(/\s+/g, ' ').split(' ').length : 0;
console.assert(countWords('') === 0, 'test 0: text is empty');
console.assert(countWords('nope') === 1, 'test 1: text contains 1 word');
console.assert(countWords('tdd is fun bro') === 4, 'test 2: text contains 4 words');
console.assert(countWords(' so is skateboarding ') === 3, 'test 3: text contains 3 words');
console.assert(countWords(`  I'm 28, I love $#@! and    multi-spaces  `) === 7, 'test 4: text contains 7 words');