Add BnB proptest

Cargo.toml

@@ -1,5 +1,5 @@
 [workspace]
 members = [
-  "bitcoin-coin-selection", "fuzz",
+  "bitcoin-coin-selection", "fuzz", "prop",
 ]
 resolver = "1"

prop/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "prop"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+proptest = "1.5.0"
+bitcoin-coin-selection = { path = "../bitcoin-coin-selection", features = ["rand"] }
+bitcoin = { git = "https://github.com/yancyribbens/rust-bitcoin.git", rev = "edcd2fb5d78be71a60709d18fb367fd56171ff26" }
+rand = "0.8.5"

prop/src/main.rs

@@ -0,0 +1,79 @@
+use bitcoin::Amount;
+use bitcoin::FeeRate;
+use bitcoin::ScriptBuf;
+use bitcoin::TxOut;
+use bitcoin::Weight;
+use proptest::prelude::*;
+
+use bitcoin_coin_selection::select_coins_bnb;
+use bitcoin_coin_selection::WeightedUtxo;
+
+#[derive(Clone, Debug)]
+pub struct Utxo {
+    output: TxOut,
+    satisfaction_weight: Weight,
+}
+
+impl WeightedUtxo for Utxo {
+    fn satisfaction_weight(&self) -> Weight {
+        self.satisfaction_weight
+    }
+
+    fn value(&self) -> Amount {
+        self.output.value
+    }
+}
+
+proptest! {
+    #[test]
+    fn test_bnb(ref mut vec in any::<Vec<u8>>()) {
+        vec.truncate(10);
+
+        let pool: Vec<Utxo> = vec.into_iter()
+            .map(|u| u64::from(*u))
+            .map(|i| Amount::from_sat(i))
+            .map(|a| {
+                let output = TxOut {
+                    value: a,
+                    script_pubkey: ScriptBuf::new()
+                };
+
+                let satisfaction_weight = Weight::ZERO;
+
+                Utxo {
+                    output,
+                    satisfaction_weight
+                }
+            })
+        .collect();
+
+        // Pick a random subset of coins by choosing only the evens
+        let solution: Vec<Amount> = pool.clone().into_iter().map(|i| {
+            if i.value() % 2 == Amount::ZERO {
+                i.value()
+            } else {
+                Amount::ZERO
+            }
+        }).collect();
+
+        // Set the target to be the sum of evens
+        let target: Amount = solution.clone().into_iter().sum();
+
+        let selection: Vec<Amount> =
+            select_coins_bnb(
+                target,
+                Amount::ZERO,
+                FeeRate::ZERO,
+                FeeRate::ZERO,
+                &pool)
+            .unwrap()
+            .map(|i| i.value()).collect();
+
+        let sum: Amount = selection.into_iter().sum();
+        assert_eq!(target, sum);
+    }
+}
+
+fn main() {
+    test_bnb();
+}