1*3117ece4Schristos# Regression tests 2*3117ece4Schristos 3*3117ece4SchristosThe regression tests run zstd in many scenarios and ensures that the size of the compressed results doesn't change. This helps us ensure that we don't accidentally regress zstd's compression ratio. 4*3117ece4Schristos 5*3117ece4SchristosThese tests get run every night by CircleCI. If the job fails you can read the diff printed by the job to ensure the change isn't a regression. If all is well you can download the `results.csv` artifact and commit the new results. Or you can rebuild it yourself following the instructions below. 6*3117ece4Schristos 7*3117ece4Schristos## Rebuilding results.csv 8*3117ece4Schristos 9*3117ece4SchristosFrom the root of the zstd repo run: 10*3117ece4Schristos 11*3117ece4Schristos``` 12*3117ece4Schristos# Build the zstd binary 13*3117ece4Schristosmake clean 14*3117ece4Schristosmake -j zstd 15*3117ece4Schristos 16*3117ece4Schristos# Build the regression test binary 17*3117ece4Schristoscd tests/regression 18*3117ece4Schristosmake clean 19*3117ece4Schristosmake -j test 20*3117ece4Schristos 21*3117ece4Schristos# Run the regression test 22*3117ece4Schristos./test --cache data-cache --zstd ../../zstd --output results.csv 23*3117ece4Schristos 24*3117ece4Schristos# Check results.csv to ensure the new results are okay 25*3117ece4Schristosgit diff 26*3117ece4Schristos 27*3117ece4Schristos# Then submit the PR 28*3117ece4Schristos``` 29