Add test to lib

src/lib.rs

@@ -164,6 +164,71 @@ mod tests {
         }
     }
 
+    use std::iter::zip;
+    #[test]
+    fn select_coins_no_solution() {
+        let target = Amount::from_sat(255432);
+        let cost_of_change = Amount::ZERO;
+        let fee_rate = FeeRate::ZERO;
+        let lt_fee_rate = FeeRate::ZERO;
+
+        let amts = [
+            27336,
+            238,
+            9225,
+            20540,
+            35590,
+            49463,
+            6331,
+            35548,
+            50363,
+            28009,
+        ];
+
+        let weights = [
+            25350,
+            106,
+            3311,
+            2633,
+            21081,
+            35260,
+            3896,
+            6377,
+            6851,
+            20236
+        ];
+
+        let utxos: Vec<_> = zip(amts, weights)
+            .map(|(a, w)| {
+                let amt = Amount::from_sat(a);
+                let tx_out = TxOut {
+                    value: amt,
+                    script_pubkey: vec![].into()
+                };
+                let weight = Weight::from_wu(w);
+
+                let u = Utxo {
+                    output: tx_out,
+                    satisfaction_weight: weight
+                };
+
+                u
+            }).collect();
+
+        let result = select_coins(
+            target,
+            cost_of_change,
+            fee_rate,
+            lt_fee_rate,
+            &utxos,
+        );
+
+        // This yields no solution because:
+        //  * BnB fails because the sum overage is greater than ost_of_change
+        //  * SRD fails because the sum is greater the utxo sum + CHANGE_LOWER
+        assert!(result.is_none());
+    }
+
     #[test]
     fn select_coins_proptest() {
         arbtest(|u| {