Freegle / Iznik / 23111

71%

master: 72%

Build Type

Pull #865

circleci

Committed by edwh

Commit Message

fix(abtest): make epsilon-greedy selection coverage deterministic

GetABTest's epsilon-greedy variant selection sat inline after the DB query,
so its two branches were reachable only through the live-DB integration test.
The 10% exploration branch (rand.Float64() < 0.1) was therefore covered only
about 1 run in 10 (Go auto-seeds the global math/rand source), making
abtest.go's reported coverage flap between 95.34% and 97.67% run to run. That
intermittently tripped the Coveralls "coverage decreased" gate on PRs that
touch no Go code at all (e.g. the PHP-only #863).

Extract the selection into chooseVariant() with the RNG injected, and add
deterministic unit tests covering exploration, exploitation, and the 0.1
threshold boundary. Runtime behaviour is unchanged; abtest.go coverage is now
stable across runs.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014e4Q3KScCbRhXw3msQ9E3S

Pull Request Pull Request #865: fix(abtest): make epsilon-greedy selection coverage deterministic

Coverage Stats

11150 of 14816 branches covered (75.26%)

Branch coverage included in aggregate %.

6 of 6 new or added lines in 1 file covered. (100.0%)

6 existing lines in 2 files now uncovered.

122196 of 172493 relevant lines covered (70.84%)

37.35 hits per line