Add sweepAll to Electrum wallet RPC client.

Consolidate payto, deserialize, and broadcast into a single sweep helper for max-payment withdrawals.

backend/src/modules/bitcoinWallet/services/ElectrumWalletRpcClient.spec.ts

@@ -17,6 +17,7 @@ describe('ElectrumWalletRpcClient', () => {
                 rpcUrl: 'http://electrum.test:7777',
                 username: 'electrum',
                 password: 'secret',
+                walletPassword: 'wallet-secret',
                 rpcTimeoutMs: 5000
             })
         } as unknown as ConfigService);
@@ -74,10 +75,10 @@ describe('ElectrumWalletRpcClient', () => {
         });
     });
 
-    describe('sumIncomingOutputValueAtomic', () => {
+    describe('sumOutputValueAtomic', () => {
         it('sums outputs paying to the target address', () => {
             expect(
-                clientTest.sumIncomingOutputValueAtomic(
+                clientTest.sumOutputValueAtomic(
                     {
                         outputs: [
                             { address: 'bc1qother', value_sats: 10_000 },
@@ -92,7 +93,7 @@ describe('ElectrumWalletRpcClient', () => {
 
         it('returns zero when no outputs match the address', () => {
             expect(
-                clientTest.sumIncomingOutputValueAtomic(
+                clientTest.sumOutputValueAtomic(
                     {
                         outputs: [{ address: 'bc1qother', value_sats: 10_000 }]
                     },
@@ -208,4 +209,80 @@ describe('ElectrumWalletRpcClient', () => {
             });
         });
     });
+
+    describe('sweepAll', () => {
+        it('creates, signs, and broadcasts a max-payment transaction', async () => {
+            mockedAxios.post
+                .mockResolvedValueOnce({
+                    data: {
+                        jsonrpc: '2.0',
+                        id: 'nullcart',
+                        result: 'signed-tx'
+                    }
+                })
+                .mockResolvedValueOnce({
+                    data: {
+                        jsonrpc: '2.0',
+                        id: 'nullcart',
+                        result: {
+                            outputs: [{ address: 'bc1qtest', value_sats: 140_000 }]
+                        }
+                    }
+                })
+                .mockResolvedValueOnce({
+                    data: {
+                        jsonrpc: '2.0',
+                        id: 'nullcart',
+                        result: 'tx-hash-1'
+                    }
+                });
+
+            await expect(client.sweepAll('bc1qtest', 10)).resolves.toEqual({
+                txHash: 'tx-hash-1',
+                amountAtomic: '140000'
+            });
+
+            expect(mockedAxios.post).toHaveBeenNthCalledWith(
+                1,
+                'http://electrum.test:7777',
+                {
+                    jsonrpc: '2.0',
+                    id: 'nullcart',
+                    method: 'payto',
+                    params: {
+                        destination: 'bc1qtest',
+                        amount: '!',
+                        feerate: '10',
+                        password: 'wallet-secret'
+                    }
+                },
+                expect.objectContaining({
+                    timeout: 120_000
+                })
+            );
+            expect(mockedAxios.post).toHaveBeenNthCalledWith(
+                2,
+                'http://electrum.test:7777',
+                {
+                    jsonrpc: '2.0',
+                    id: 'nullcart',
+                    method: 'deserialize',
+                    params: { tx: 'signed-tx' }
+                },
+                expect.any(Object)
+            );
+            expect(mockedAxios.post).toHaveBeenNthCalledWith(
+                3,
+                'http://electrum.test:7777',
+                {
+                    jsonrpc: '2.0',
+                    id: 'nullcart',
+                    method: 'broadcast',
+                    params: { tx: 'signed-tx' }
+                },
+                expect.any(Object)
+            );
+        });
+    });
+
 });

backend/src/modules/bitcoinWallet/services/ElectrumWalletRpcClient.ts

@@ -88,6 +88,85 @@ export class ElectrumWalletRpcClient {
         };
     }
 
+    async sweepAll(
+        destinationAddress: string,
+        feeRateSatVbyte: number
+    ): Promise<{ txHash: string; amountAtomic: string }> {
+        const signedTransaction = await this.payToMax(destinationAddress, feeRateSatVbyte);
+        const transaction = await this.deserializeTransaction(signedTransaction);
+
+        const amountAtomic = this.sumOutputValueAtomic(transaction, destinationAddress);
+
+        if (amountAtomic === '0') {
+            throw new Error('Withdrawal transaction has no spendable output to the destination address');
+        }
+
+        const txHash = await this.broadcast(signedTransaction);
+
+        return { txHash, amountAtomic };
+    }
+
+    private async payToMax(destinationAddress: string, feeRateSatVbyte: number): Promise<string> {
+        const { walletPassword } = this.configService.get('electrumWallet') as Config['electrumWallet'];
+
+        const signedTransaction = await this.call<string>(
+            'payto',
+            {
+                destination: destinationAddress,
+                amount: '!',
+                feerate: String(feeRateSatVbyte),
+                password: walletPassword
+            },
+            { timeoutMs: 120_000 }
+        );
+
+        if (!signedTransaction) {
+            throw new Error('Electrum wallet RPC payto returned no transaction');
+        }
+
+        return signedTransaction;
+    }
+
+    private async broadcast(signedTransaction: string): Promise<string> {
+        const txHash = await this.call<string>('broadcast', { tx: signedTransaction });
+
+        if (!txHash) {
+            throw new Error('Electrum wallet RPC broadcast returned no transaction hash');
+        }
+
+        return txHash;
+    }
+
+    private async deserializeTransaction(signedTransaction: string): Promise<ElectrumWalletDeserializedTransaction> {
+        return this.call<ElectrumWalletDeserializedTransaction>('deserialize', { tx: signedTransaction });
+    }
+
+    private sumOutputValueAtomic(transaction: ElectrumWalletDeserializedTransaction, address: string): string {
+        if (!Array.isArray(transaction.outputs)) {
+            return '0';
+        }
+
+        return transaction.outputs.reduce((sum, output) => {
+            if (output.address !== address || !Number.isFinite(output.value_sats) || output.value_sats <= 0) {
+                return sum;
+            }
+
+            return addAtomic(sum, String(output.value_sats));
+        }, '0');
+    }
+
+    async getSeed(): Promise<string> {
+        const { walletPassword } = this.configService.get('electrumWallet') as Config['electrumWallet'];
+
+        const mnemonic = await this.call<string>('getseed', { password: walletPassword });
+
+        if (!mnemonic) {
+            throw new Error('Electrum wallet RPC getseed returned no mnemonic');
+        }
+
+        return mnemonic;
+    }
+
     async createAddress(label?: string): Promise<string> {
         const address = await this.call<string>('createnewaddress');
 
@@ -120,12 +199,8 @@ export class ElectrumWalletRpcClient {
                 }
 
                 const serializedTransaction = await this.call<string>('gettransaction', { txid: txHash });
-
-                const transaction = await this.call<ElectrumWalletDeserializedTransaction>('deserialize', {
-                    tx: serializedTransaction
-                });
-
-                const amountAtomic = this.sumIncomingOutputValueAtomic(transaction, address);
+                const transaction = await this.deserializeTransaction(serializedTransaction);
+                const amountAtomic = this.sumOutputValueAtomic(transaction, address);
 
                 return this.mapIncomingTransfer(entry, amountAtomic, blockHeight);
             })
@@ -134,20 +209,6 @@ export class ElectrumWalletRpcClient {
         return transfers.filter((transfer): transfer is ElectrumWalletIncomingTransfer => transfer !== null);
     }
 
-    private sumIncomingOutputValueAtomic(transaction: ElectrumWalletDeserializedTransaction, address: string): string {
-        if (!Array.isArray(transaction.outputs)) {
-            return '0';
-        }
-
-        return transaction.outputs.reduce((sum, output) => {
-            if (output.address !== address || !Number.isFinite(output.value_sats) || output.value_sats <= 0) {
-                return sum;
-            }
-
-            return addAtomic(sum, String(output.value_sats));
-        }, '0');
-    }
-
     private mapIncomingTransfer(
         entry: ElectrumWalletAddressHistoryEntry,
         amountAtomic: string,

backend/src/modules/bitcoinWallet/types/ElectrumWalletRpcClientTest.ts

@@ -8,5 +8,5 @@ export type ElectrumWalletRpcClientTest = {
         amountAtomic: string,
         blockHeight: number | null
     ) => ElectrumWalletIncomingTransfer | null;
-    sumIncomingOutputValueAtomic: (transaction: ElectrumWalletDeserializedTransaction, address: string) => string;
+    sumOutputValueAtomic: (transaction: ElectrumWalletDeserializedTransaction, address: string) => string;
 };