image: © Richard Vignola (CC BY-NC-ND)

Three collected thoughts on the use of code coverage as a quality metric.

Incentives with negative consequences are called perverse incentives; asking developers to reach a particular code coverage goal is clearly a perverse incentive.

Mark Seemann, 2015

What are possible negative consequences of setting a specific code coverage as a target?

Sufficiency of testing is much more complicated attribute than coverage can answer. I would say you are doing enough testing if the following is true:

  • You rarely get bugs that escape into production, and
  • You are rarely hesitant to change some code for fear it will cause production bugs.

Martin Fowler, bliki, 2012

Are you doing enough testing?

If a part of your test suite is weak in a way that coverage can detect, it’s likely also weak in a way coverage can’t detect.

Brian Marick, from bliki, 2012

Can you give some examples of ways your suite can be weak which code coverage can not detect?


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