Optional exit code > 0 when coverage percentage goes down

[colszowka]

See http://twitter.com/#!/hayafirst/status/28368786944

And my responses:
Check out custom exit behaviour: http://bit.ly/953iOR - could raise an exception after result change. See http://bit.ly/9PSaOt
Basically, cache the result.covered_percent somewhere, then later compare it with previous and cause an exit with status > 0

---

This could be an (optional) built-in functionality.
The SimpleCov.result.covered_percent should be stored in coverage_path/last_coverage_percent, then compared with the current run.

Configure with:

SimpleCov.start(:rails) do
  check_coverage_change 
end

[ywen]

This will be awesome. Thank you. Do you feel it is hard or relatively easy? I would love to help if I may.

[dlindahl]

Not sure how this would work when bounding between filtered and unfiltered specs as the coverage amount would change between test runs.

However, you may want to checkout cane from Square. It is a code quality tool that specifically allows for build failures when code coverage drops below a certain amount.

[colszowka]

This will be very easy to add now that #90 is part of master, basically I'd just add a refuse_coverage_drop config shorthand that under the hood uses maximum_coverage_drop 0.