coinosv3.git/tools/gift-build-test.js, branch master

Fix "Cannot mix BigInt and other types" when creating an on-chain gift.

2026-09-07T14:54:23Z

_buildGiftPsbt (the v2 ephemeral-key gift builder) subtracted the funding fee — _giftFundFee returns a Number — directly from BigInt coin sums (sum - _giftFundFee(...), sum - gift - _giftFundFee(...)), which throws in JS. Any on-chain (Savings) gift creation hit it: "Split a coin first", "Lock the whole coin", and gift-all. Wrap the fee in BigInt at those sites (new fundFee() helper). Adds tools/gift-build-test.js — the on-chain gift BUILDER had no coverage, which is how this shipped. It builds a specific-amount gift, a whole-balance gift, and the split carve-out shape (all three fee branches) against a mock wallet and asserts they produce claimable v2 codes without throwing. Co-Authored-By: Claude Opus 4.8 Claude-Session: https://claude.ai/code/session_01MGzU12QrAA4G6BYGzGVdXz