feat: allow setting the minimum profit via the CLI

Author: gakonst

src/keeper.rs

@@ -39,6 +39,7 @@ impl<P: JsonRpcClient> Keeper<P> {
         liquidations: Address,
         uniswap: Address,
         flashloan: Address,
+        min_profit: U256,
         state: Option<State>,
     ) -> Result<Keeper<P>> {
         let (borrowers, vaults, last_block) = match state {
@@ -47,8 +48,15 @@ impl<P: JsonRpcClient> Keeper<P> {
         };
 
         let borrowers = Borrowers::new(controller, client.clone(), borrowers).await;
-        let liquidator =
-            Liquidator::new(liquidations, uniswap, flashloan, client.clone(), vaults).await;
+        let liquidator = Liquidator::new(
+            liquidations,
+            uniswap,
+            flashloan,
+            min_profit,
+            client.clone(),
+            vaults,
+        )
+        .await;
 
         Ok(Self {
             client,
@@ -62,7 +70,7 @@ impl<P: JsonRpcClient> Keeper<P> {
         let watcher = self.client.clone();
         let mut on_block = watcher.watch_blocks().await?.stream();
 
-        while let Some(_) = on_block.next().await {
+        while on_block.next().await.is_some() {
             let file = std::fs::OpenOptions::new()
                 .read(true)
                 .write(true)

src/liquidations.rs

@@ -30,6 +30,9 @@ pub struct Liquidator<P> {
     /// our RPC endpoint
     multicall: Multicall<P, Wallet>,
 
+    /// The minimum profit to be extracted per liquidation
+    min_profit: U256,
+
     pending_liquidations: HashMap<Address, TxHash>,
     pending_auctions: HashMap<Address, TxHash>,
 }
@@ -51,6 +54,7 @@ impl<P: JsonRpcClient> Liquidator<P> {
         liquidations: Address,
         uniswap: Address,
         flashloan: Address,
+        min_profit: U256,
         client: Arc<Client<P, Wallet>>,
         auctions: HashMap<Address, Auction>,
     ) -> Self {
@@ -63,6 +67,7 @@ impl<P: JsonRpcClient> Liquidator<P> {
             uniswap: Uniswap::new(uniswap, client.clone()),
             flashloan,
             multicall,
+            min_profit,
             auctions,
 
             pending_liquidations: HashMap::new(),
@@ -149,10 +154,7 @@ impl<P: JsonRpcClient> Liquidator<P> {
             return Ok(());
         }
 
-        // TODO: Should this be done via gas estimation? A minimum 0.1 ETH
-        // profit seems good enough.
-        let min_profit_eth = U256::from(1e17 as u64);
-        let args = abi::encode(&(user, min_profit_eth).into_tokens());
+        let args = abi::encode(&(user, self.min_profit).into_tokens());
 
         // Calls Uniswap's `swap` function which will optimistically let us
         // borrow the debt, which will then make a callback to the flashloan
@@ -204,7 +206,7 @@ impl<P: JsonRpcClient> Liquidator<P> {
             // only iterate over users that do not have pending liquidations
             if let Some(tx_hash) = self.pending_liquidations.get(&user) {
                 trace!(tx_hash = ?tx_hash, user = ?user, "liquidation not confirmed yet");
-                continue
+                continue;
             }
 
             if !details.is_collateralized {

src/main.rs

@@ -52,6 +52,9 @@ struct Opts {
 
     #[options(help = "the file to be used for persistence", default = "data.json")]
     file: PathBuf,
+
+    #[options(help = "the minimum profit per liquidation")]
+    min_profit: U256,
 }
 
 #[tokio::main]
@@ -93,6 +96,7 @@ async fn main() -> anyhow::Result<()> {
         opts.liquidations,
         opts.uniswap,
         opts.flashloan,
+        opts.min_profit,
         state,
     )
     .await?;