KarpelesLab / libwallet / 25256164343

24%

Build Type

push

github

Committed by MagicalTux

Commit Message

wlttx/simulate: dry-run preview for unsigned bitcoin transfers

simulateBitcoin previously only worked on a tx that had already
been built (tx.Raw populated) — it decoded what was already on the
wire. That's not what an approval UI wants: at approval time the
tx hasn't been built yet because the user hasn't confirmed.

New dry-run path: when Type=="bitcoin_transfer" + From + To +
Amount are set but Raw is empty, simulateBitcoin runs the same
fetchUTXOs → coin selection → fee math buildBitcoinTx would,
stops short of signing, and returns the planned shape:
  - inputs with resolved amount + address + path (so the UI can
    flag "spending change UTXO m/1/0" or "received at L...")
  - recipient + change outputs with resolved addresses
  - fee in sats, vsize in vbytes
  - new BitcoinChange field separating change from recipient
    (decode-only sims couldn't tell those apart)
  - new BitcoinVSize field so the approval UI can render
    "fee = X sat × Y vbytes" without reverse-math

Honours Transaction.UTXOs (manual selection from the previous
commits) so a manual coin-pick previews exactly what it'll spend.

Decode-from-Raw path unchanged.

Dart's TransactionSimulation grows bitcoinChange / bitcoinVSize +
adds path to BitcoinIO. All optional / empty-string defaults so
post-build sims stay backwards-compatible with the old shape.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

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