Add multi output spend support

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- added: Support for multiple spend targets.
+
 ## 1.4.2 (2025-04-01)
 
 - fixed: Small internal implementation cleanup on how transactions are saved.

src/MoneroEngine.ts

@@ -2,7 +2,7 @@
  * Created by paul on 7/7/17.
  */
 
-import { div, eq, gte, lt, sub } from 'biggystring'
+import { add, div, eq, gte, lt, sub } from 'biggystring'
 import type { Disklet } from 'disklet'
 import {
   EdgeCorePluginOptions,
@@ -600,11 +600,15 @@ export class MoneroEngine implements EdgeCurrencyEngine {
       throw new TypeError('Missing destination address')
     }
 
-    const options = {
-      amount: '0',
+    const options: CreateTransactionOptions = {
       isSweepTx: true,
       priority: translateFee(edgeSpendInfo.networkFeeOption),
-      targetAddress: publicAddress
+      targets: [
+        {
+          amount: '0',
+          targetAddress: publicAddress
+        }
+      ]
     }
 
     const result = await this.createMyMoneroTransaction(options, privateKeys)
@@ -642,39 +646,45 @@ export class MoneroEngine implements EdgeCurrencyEngine {
     const { memos = [] } = edgeSpendInfo
     const privateKeys = asPrivateKeys(opts?.privateKeys)
 
-    // Monero can only have one output
-    // TODO: The new SDK fixes this!
-    if (edgeSpendInfo.spendTargets.length !== 1) {
-      throw new Error('Error: only one output allowed')
-    }
+    const { spendTargets } = edgeSpendInfo
 
-    const [spendTarget] = edgeSpendInfo.spendTargets
-    const { publicAddress, nativeAmount } = spendTarget
-    if (publicAddress == null) {
-      throw new TypeError('Missing destination address')
-    }
-    if (nativeAmount == null || eq(nativeAmount, '0')) {
-      throw new NoAmountSpecifiedError()
-    }
+    let totalAmount = '0'
+    const targets: CreateTransactionOptions['targets'] = []
 
-    if (
-      gte(
-        nativeAmount,
-        this.walletLocalData.totalBalances.get(PRIMARY_CURRENCY_TOKEN_ID) ?? '0'
-      )
-    ) {
-      if (gte(this.walletLocalData.lockedXmrBalance, nativeAmount)) {
-        throw new PendingFundsError()
-      } else {
-        throw new InsufficientFundsError({ tokenId: PRIMARY_CURRENCY_TOKEN_ID })
+    for (const spendTarget of spendTargets) {
+      const { publicAddress, nativeAmount } = spendTarget
+      if (publicAddress == null) {
+        throw new TypeError('Missing destination address')
+      }
+      if (nativeAmount == null || eq(nativeAmount, '0')) {
+        throw new NoAmountSpecifiedError()
+      }
+      totalAmount = add(totalAmount, nativeAmount)
+      if (
+        gte(
+          totalAmount,
+          this.walletLocalData.totalBalances.get(PRIMARY_CURRENCY_TOKEN_ID) ??
+            '0'
+        )
+      ) {
+        if (gte(this.walletLocalData.lockedXmrBalance, totalAmount)) {
+          throw new PendingFundsError()
+        } else {
+          throw new InsufficientFundsError({
+            tokenId: PRIMARY_CURRENCY_TOKEN_ID
+          })
+        }
       }
+      targets.push({
+        amount: div(nativeAmount, '1000000000000', 12),
+        targetAddress: publicAddress
+      })
     }
 
     const options: CreateTransactionOptions = {
-      amount: div(nativeAmount, '1000000000000', 12),
       isSweepTx: false,
       priority: translateFee(edgeSpendInfo.networkFeeOption),
-      targetAddress: publicAddress
+      targets
     }
     this.log(`Creating transaction: ${JSON.stringify(options, null, 1)}`)
 

src/MyMoneroApi.ts

@@ -44,11 +44,13 @@ export interface BalanceResults {
 }
 
 export interface CreateTransactionOptions {
-  amount: string
+  targets: Array<{
+    amount: string
+    targetAddress: string
+  }>
   isSweepTx?: boolean
   paymentId?: string
   priority?: Priority
-  targetAddress: string
 }
 
 const asNumberBoolean: Cleaner<boolean> = raw => {
@@ -238,13 +240,7 @@ export class MyMoneroApi {
     opts: CreateTransactionOptions
   ): Promise<CreatedTransaction> {
     const { address, privateSpendKey, privateViewKey, publicSpendKey } = keys
-    const {
-      amount,
-      isSweepTx = false,
-      paymentId,
-      priority = 1,
-      targetAddress
-    } = opts
+    const { isSweepTx = false, paymentId, priority = 1, targets } = opts
 
     // Grab the UTXO set:
     const unspentOuts = await this.fetchPostMyMonero('get_unspent_outs', {
@@ -268,14 +264,14 @@ export class MyMoneroApi {
       })
     }
 
+    const destinations = targets.map(t => ({
+      send_amount: t.amount,
+      to_address: t.targetAddress
+    }))
+
     // Make the transaction:
     return await this.cppBridge.createTransaction({
-      destinations: [
-        {
-          send_amount: amount,
-          to_address: targetAddress
-        }
-      ],
+      destinations,
       priority,
       address,
       paymentId,