Regression Test Selection (RTS) is a technique to intellegently select tests to run, without spending too much resources on testing, but still detecting bad code changes. Conceptually, a selection strategy for CQ accepts changed files as input and returns tests to run as output.
As of February 2021, most of the documention can be found at https://bit.ly/chromium-rts. This document is focused on particular tasks that a developer might need to perform in this code base.
note: TODO(nodir): move relevant parts from bit.ly/chromium-rts to this README.md.
Chromium's selection strategy can be found in ./cmd/rts-chromium/strategy.go. It is primarily based on ./filegraph with some Chromium-specific rules.
Changes to the selection strategy should be accompanied with the safety/efficiency scores before and after the change on the same dataset, in order to ensure that the change is in fact an improvement.
chrome-rts Cloud project by being a member of email@example.com group or by contacting firstname.lastname@example.org.
go run ./cmd/rts-chromium fetch-rejections \ -builder linux-rel \ -from 2021-02-01 -to 2021-03-01 \ -out linux-rel.rej
go run ./cmd/rts-chromium fetch-durations \ -builder linux-rel \ -from 2021-02-01 -to 2021-02-08 \ -out linux-rel.dur
go run ./cmd/rts-chromium create-model \ -checkout ~/chromium/src -rejections linux-rel.rej \ -durations linux-rel.dur \ -model-dir ./model \
Model creation can take 30min on a powerful machine. If you are developing on your laptop, it is recommended to scp the binary to a more powerful machine and run the model creation there.