fix: cap forum post engagement time depreciation with min instead of max - #1037
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fix: cap forum post engagement time depreciation with min instead of max#1037TowyTowy wants to merge 1 commit into
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calculateEngagement applies a time-based depreciation to reddit and hacker-news posts older than depreciatePostsOlderThanHours. The ramp used math.Max(elapsed-threshold, maxDepreciationAfterHours), which is always >= maxDepreciationAfterHours, so the depreciation factor was always >= 1. As a result every post past the 7h threshold was immediately hit with the full maxDepreciation (0.9), defeating the gradual decay, and posts older than threshold+maxDepreciationAfterHours got a factor > 1, producing negative engagement scores. Use math.Min so the factor ramps from 0 to 1 over maxDepreciationAfterHours and is capped there, restoring the intended gradual decay and flooring engagement at 1-maxDepreciation. Co-Authored-By: Claude <noreply@anthropic.com>
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The time-based depreciation in
calculateEngagement(used by the Reddit and Hacker News widgets) usesmath.Max(elapsed - depreciatePostsOlderThanHours, maxDepreciationAfterHours). Becausemath.Max(x, maxDepreciationAfterHours)is always ≥maxDepreciationAfterHours, the depreciation factor is always ≥ 1. This means:maxDepreciation(0.9) instead of decaying gradually — there's a cliff at 7h rather than a ramp towardmaxDepreciationAfterHours.depreciatePostsOlderThanHours + maxDepreciationAfterHours(31h) get a factor > 1, producing negative engagement scores.Switching to
math.Mincaps the ramp numerator atmaxDepreciationAfterHours, so the factor rises from 0 to 1 over the intended window and stops there — restoring gradual decay and flooring engagement at1 - maxDepreciation(0.1).Added
TestCalculateEngagementTimeDepreciation, which fails on the current code (8h post → 0.1, 50h post → −0.61) and passes after the fix.go vet/gofmtclean.Prepared with AI assistance (Claude) and reviewed/verified by me.