🐛 (bitcoin-wallet): fix uncheck error

Author: yuanyu90221

pointers-and-errors/bitcoin-and-wallet_test.go

@@ -25,6 +25,12 @@ func TestWallet(t *testing.T) {
 		}
 	}
 
+	assertNoError := func(t testing.TB, got error) {
+		t.Helper()
+		if got != nil {
+			t.Fatal("got an error but didn't want one")
+		}
+	}
 	t.Run("deposit", func(t *testing.T) {
 		wallet := Wallet{}
 
@@ -36,8 +42,9 @@ func TestWallet(t *testing.T) {
 	t.Run("withdraw", func(t *testing.T) {
 		wallet := Wallet{balance: Bitcoin(20)}
 
-		wallet.Withdraw(Bitcoin(10))
+		err := wallet.Withdraw(Bitcoin(10))
 		want := Bitcoin(10)
+		assertNoError(t, err)
 		assertBalance(t, wallet, want)
 	})