Fix melt to return whole change

src/CashuWallet.ts

@@ -26,7 +26,8 @@ import {
 	bytesToNumber,
 	getDecodedToken,
 	getDefaultAmountPreference,
-	splitAmount
+	splitAmount,
+	sumProofs
 } from './utils';
 import { validateMnemonic } from '@scure/bip39';
 import { wordlist } from '@scure/bip39/wordlists/english';
@@ -443,7 +444,7 @@ class CashuWallet {
 		const keys = await this.getKeys(options?.keysetId);
 
 		const { blindedMessages, secrets, rs } = this.createBlankOutputs(
-			meltQuote.fee_reserve,
+			sumProofs(proofsToSend) - meltQuote.amount,
 			keys.id,
 			options?.counter
 		);
@@ -463,6 +464,8 @@ class CashuWallet {
 		};
 	}
 
+
+
 	/**
 	 * Helper function that pays a Lightning invoice directly without having to create a melt quote before
 	 * The combined amount of Proofs must match the payment amount including fees.

src/utils.ts

@@ -4,6 +4,9 @@ import { TOKEN_PREFIX, TOKEN_VERSION } from './utils/Constants';
 import { bytesToHex, hexToBytes } from '@noble/curves/abstract/utils';
 import { sha256 } from '@noble/hashes/sha256';
 
+export function sumProofs(proofs: Array<Proof>) {
+	return proofs.reduce((acc: number, proof: Proof) => acc + proof.amount, 0);
+}
 
 function splitAmount(value: number, amountPreference?: Array<AmountPreference>): Array<number> {
 	const chunks: Array<number> = [];