Improve test coverage

[mayn]

No description provided.

[coveralls]

Coverage increased (+8.8%) to 73.76% when pulling 7424089 on improve-test-coverage into c90849f on master.

[coveralls]

Coverage increased (+9.8%) to 74.798% when pulling 9baff79 on improve-test-coverage into c90849f on master.

[coveralls]

Coverage increased (+10.3%) to 75.288% when pulling ca7c6a6 on improve-test-coverage into c90849f on master.

[coveralls]

Coverage increased (+14.9%) to 79.901% when pulling 8b133a7 on improve-test-coverage into c90849f on master.

[coveralls]

Coverage increased (+16.4%) to 81.384% when pulling 91f493e on improve-test-coverage into c90849f on master.

[coveralls]

Coverage increased (+17.2%) to 82.208% when pulling dbcbe54 on improve-test-coverage into c90849f on master.

[coveralls]

Coverage increased (+17.4%) to 82.372% when pulling 46be8b4 on improve-test-coverage into c90849f on master.