>Coverage is a measure used to describe the degree to which the source code of a program is executed when a particular test suite runs. A program with high test coverage, measured as a percentage, has had more of its source code executed during testing, which suggests it has a lower chance of containing undetected software bugs compared to a program with low test coverage.

In case folks are wondering about what we mean by coverage...

PS. Love Rails.

Writing comprehensive tests isn't an "enormous cost."

Having high test coverage (especially in dynamic languages) has been industry standard for years. I haven't worked at a place that accepts poorly covered PRs in a very long time.

>Coverage is a measure used to describe the degree to which the source code of a program is executed when a particular test suite runs. A program with high test coverage, measured as a percentage, has had more of its source code executed during testing, which suggests it has a lower chance of containing undetected software bugs compared to a program with low test coverage.

In case folks are wondering about what we mean by coverage...