fix: assert that Monero address pool sums to one

monero-sys/src/lib.rs

@@ -1990,8 +1990,7 @@ mod tests {
         // We check all but the last amount since the last one gets the remainder
         let mut percentages_respected = true;
         for i in 0..percentages.len() - 1 {
-            let expected_amount =
+            let expected_amount = ((balance.as_pico() as f64) * percentages[i]).floor() as u64;
-                ((balance.as_pico() as f64) * percentages[i]).floor() as u64;
             if amounts[i].as_pico() != expected_amount {
                 percentages_respected = false;
                 break;

src-gui/src/renderer/components/modal/swap/pages/done/XmrRedeemInMempoolPage.tsx

@@ -55,7 +55,7 @@ export default function XmrRedeemInMempoolPage(
                           color: theme.palette.text.primary,
                         })}
                       >
-                        {pool.label} ({pool.percentage}%)
+                        {pool.label} ({pool.percentage * 100}%)
                       </Typography>
                     </Box>
                     <Typography

src-gui/src/renderer/components/pages/history/table/HistoryRowExpanded.tsx

@@ -133,7 +133,7 @@ export default function HistoryRowExpanded({
                           color: theme.palette.text.primary,
                         })}
                       >
-                        {pool.label} ({pool.percentage}%)
+                        {pool.label} ({pool.percentage * 100}%)
                       </Typography>
                       <Typography
                         variant="caption"

src-gui/src/renderer/rpc.ts

@@ -186,12 +186,12 @@ export async function buyXmr(
     address_pool.push(
       {
         address: monero_receive_address,
-        percentage: 100 - donation_percentage * 100,
+        percentage: 1 - donation_percentage,
         label: "Your wallet",
       },
       {
         address: donation_address,
-        percentage: donation_percentage * 100,
+        percentage: donation_percentage,
         label: "Tip to the developers",
       },
     );

swap/src/cli/api/request.rs

@@ -598,6 +598,7 @@ pub async fn buy_xmr(
     } = buy_xmr;
 
     monero_receive_pool.assert_network(context.config.env_config.monero_network)?;
+    monero_receive_pool.assert_sum_to_one()?;
 
     let bitcoin_wallet = Arc::clone(
         context

swap/src/monero.rs

@@ -343,6 +343,23 @@ impl MoneroAddressPool {
 
         Ok(())
     }
+
+    /// Assert that the sum of the percentages in the address pool is 1 (allowing for a small tolerance)
+    pub fn assert_sum_to_one(&self) -> Result<()> {
+        let sum = self
+            .0
+            .iter()
+            .map(|address| address.percentage())
+            .sum::<Decimal>();
+
+        const TOLERANCE: f64 = 1e-6;
+
+        if (sum - Decimal::ONE).abs() > Decimal::from_f64(TOLERANCE).unwrap() {
+            bail!("Address pool percentages do not sum to 1");
+        }
+
+        Ok(())
+    }
 }
 
 impl From<::monero::Address> for MoneroAddressPool {
@@ -907,7 +924,9 @@ mod tests {
         assert!(LabeledMoneroAddress::new(address, Decimal::ZERO, "test".to_string()).is_ok());
         assert!(LabeledMoneroAddress::new(address, Decimal::ONE, "test".to_string()).is_ok());
         assert!(LabeledMoneroAddress::new(address, Decimal::new(5, 1), "test".to_string()).is_ok()); // 0.5
-        assert!(LabeledMoneroAddress::new(address, Decimal::new(9925, 4), "test".to_string()).is_ok()); // 0.9925
+        assert!(
+            LabeledMoneroAddress::new(address, Decimal::new(9925, 4), "test".to_string()).is_ok()
+        ); // 0.9925
 
         // Invalid percentages should fail
         assert!(