Improving coverage

[caarlos0]

While I was improving the unit tests, I found a 🐛

Also, improved some stuff..

[coveralls]

Coverage decreased (-1.21%) to 90.79% when pulling 529fbf0 on coverage into f0af4e3 on master.

[coveralls]

Coverage decreased (-1.59%) to 90.41% when pulling 529fbf0 on coverage into f0af4e3 on master.

[coveralls]

Coverage decreased (-0.22%) to 91.78% when pulling e9776ba on coverage into f0af4e3 on master.

[coveralls]

Coverage decreased (-0.22%) to 91.78% when pulling f63fe62 on coverage into f0af4e3 on master.

[coveralls]

Coverage decreased (-0.33%) to 91.67% when pulling a9dce70 on coverage into f0af4e3 on master.

[coveralls]

Coverage decreased (-0.45%) to 91.55% when pulling a9dce70 on coverage into f0af4e3 on master.