Fix sub-cent fee rounding in YeetfulStaking (closes #1) - #3
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ACC_PRECISION 1e18 was too small: an 18-dec memecoin stake (Flaunch supply ~1e29) against 6-dec USDC meant any sub-$1000 routeFees rounded the per-share increment to zero, stranding the USDC in the vault. Bump to 1e30 and carry the truncation remainder forward across routes so dust accrues instead of stranding. Adds regression tests: a single $0.001 route at 100B supply stays claimable, and 50 non-share-aligned tiny routes accrue losslessly (within 1 micro). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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What
Fixes the High finding from the pre-publish security review (#1): per-call USDC fees rounded to zero and stranded in the vault.
Why
accFeePerShare += amount * ACC_PRECISION / totalStakedwithACC_PRECISION = 1e18is too coarse when the stake token is an 18-dec Flaunch memecoin (~1e29 supply) and the payout is 6-dec USDC at fraction-of-a-cent granularity. At ~1e27 staked, any deposit under ~$1000 rounded the increment to zero, soaccFeePerSharenever moved and the routed USDC piled up unclaimable.Change
ACC_PRECISION1e18 → 1e30 — keeps even a 1-micro-USDC route non-zero at full supply.feeRemainder: carry the truncation remainder (scaled USDC) into the next route's numerator so dust accrues across routes instead of stranding. The matching USDC stays in the contract until it converts — solvency preserved.staked * accFeePerSharereconstructsearned * 1e30, bounded by total-routed-USDC × 1e30 ≪ 2^256.Tests (19/19 green)
test_subCentFee_atFullSupply_notStranded— a single $0.001 route against a 100B (1e29) stake stays fully claimable (was 0 under 1e18).test_remainderCarry_losslessOverManyRoutes— 50 non-share-aligned tiny routes accrue losslessly (within 1 micro).Also renames the README H1 to match the
Yeetful/contractsrepo name (separate commit).Medium finding #2 (permissionless
launch()) is left as a separate issue per the publish plan.Closes #1