Added tests for the iscoinspendable method

Signed-off-by: Robert Gogete <gogeterobert@yahoo.com>

Author: gogeterobert

test/application/services/WalletService.test.ts

@@ -78,4 +78,34 @@ describe('WalletService Integration', () => {
     // Try to load a non-existent wallet
     await expect(WalletService.loadWallet('nonexistent')).rejects.toThrow('Wallet Not Found');
   });
+
+  describe('isCoinSpendable', () => {
+    const coinId = Buffer.from('aabbcc', 'hex');
+    let peer: any;
+
+    beforeEach(() => {
+      peer = {
+        isCoinSpent: jest.fn(),
+      };
+    });
+
+    it('should return true if peer.isCoinSpent resolves true', async () => {
+      peer.isCoinSpent.mockResolvedValue(true);
+      const result = await WalletService.isCoinSpendable(peer, coinId);
+      expect(result).toBe(true);
+      expect(peer.isCoinSpent).toHaveBeenCalledWith(coinId, expect.any(Number), expect.any(Buffer));
+    });
+
+    it('should return false if peer.isCoinSpent resolves false', async () => {
+      peer.isCoinSpent.mockResolvedValue(false);
+      const result = await WalletService.isCoinSpendable(peer, coinId);
+      expect(result).toBe(false);
+    });
+
+    it('should return false if peer.isCoinSpent throws', async () => {
+      peer.isCoinSpent.mockRejectedValue(new Error('fail'));
+      const result = await WalletService.isCoinSpendable(peer, coinId);
+      expect(result).toBe(false);
+    });
+  });
 });