text: const sumOfFiles = require('./sum');
  
  test('it works with the example case', () => {
      return sumOfFiles('/example/A.txt')
          .then((output) => {
              expect(output).toMatchObject({
                  'A.txt': 111,
                  'B.txt': 39,
                  'C.txt': 12
              });
          });
  })
  
  test('it works with 2 separate branches', () => {
      return sumOfFiles('/example2/A.txt')
          .then((output) => {
              expect(output).toMatchObject({
                  'A.txt': 90,
                  'B.txt': 23,
                  'C.txt': 7,
                  'D.txt': 13,
              });
          });
  })
  
  test('it works with files declared at the end', () => {
      return sumOfFiles('/example3/A.txt')
          .then((output) => {
              expect(output).toMatchObject({
                  'A.txt': 111,
                  'B.txt': 39,
                  'C.txt': 12
              });
          });
  })
  
  test('it throws an error if a file does not exist', () => {
      return sumOfFiles('/example4/A.txt')
          .catch(error => {
              expect(error).toBeDefined()
          })
  })
  