Release: develop -> main

src/integration/blockchain/bitcoin/services/__tests__/bitcoin-fee.service.spec.ts

@@ -97,6 +97,35 @@ describe('BitcoinFeeService', () => {
     });
   });
 
+  // --- getSendFeeRate() Tests --- //
+
+  describe('getSendFeeRate()', () => {
+    const feeConfig = { allowUnconfirmedUtxos: true, cpfpFeeMultiplier: 2.0, defaultFeeMultiplier: 1.5 };
+
+    beforeEach(() => {
+      Object.defineProperty(service, 'feeConfig', { get: () => feeConfig });
+    });
+
+    it('should round fee rate to 3 decimal places (Bitcoin Core send RPC limit)', async () => {
+      // estimatesmartfee returning 1.935 sat/vB multiplied by cpfpFeeMultiplier=2.0
+      // produces 3.8699999999999997 in JS due to floating-point arithmetic; Bitcoin Core
+      // rejects fee_rate with more than 3 decimal places via "Invalid amount".
+      mockClient.estimateSmartFee.mockResolvedValueOnce(1.935);
+
+      const result = await service.getSendFeeRate();
+
+      expect(result).toBe(3.87);
+    });
+
+    it('should preserve integer fee rates without artifacts', async () => {
+      mockClient.estimateSmartFee.mockResolvedValueOnce(10);
+
+      const result = await service.getSendFeeRate();
+
+      expect(result).toBe(20); // 10 * cpfpFeeMultiplier (2.0)
+    });
+  });
+
   // --- getTxFeeRate() Tests --- //
 
   describe('getTxFeeRate()', () => {

src/integration/blockchain/bitcoin/services/bitcoin-based-fee.service.ts

@@ -1,5 +1,6 @@
 import { DfxLogger } from 'src/shared/services/dfx-logger';
 import { AsyncCache, CacheItemResetPeriod } from 'src/shared/utils/async-cache';
+import { Util } from 'src/shared/utils/util';
 import { NodeClient } from '../node/node-client';
 
 export type TxFeeRateStatus = 'unconfirmed' | 'confirmed' | 'not_found' | 'error';
@@ -89,6 +90,8 @@ export abstract class BitcoinBasedFeeService {
     const { allowUnconfirmedUtxos, cpfpFeeMultiplier, defaultFeeMultiplier } = this.feeConfig;
     const multiplier = allowUnconfirmedUtxos ? cpfpFeeMultiplier : defaultFeeMultiplier;
 
-    return baseRate * multiplier;
+    // Bitcoin Core's send RPC parses fee_rate with decimals=3; un-rounded floating-point
+    // products (e.g. 1.935 * 2 = 3.8699999999999997) are rejected with "Invalid amount".
+    return Util.round(baseRate * multiplier, 3);
   }
 }