Add tests for coordinator pnl calculation

Additionally adds more tests to `trade::cfd` that reflect the pnl calculation on the trader side.
This reflects that the traders losses are the coordinator's profits and vice versa.

coordinator/src/node.rs

@@ -57,7 +57,7 @@ pub mod storage;
 pub mod unrealized_pnl;
 
 /// The leverage used by the coordinator for all trades.
-const COORDINATOR_LEVERAGE: f32 = 1.0;
+pub const COORDINATOR_LEVERAGE: f32 = 1.0;
 
 #[derive(Debug, Clone)]
 pub struct NodeSettings {

coordinator/src/node/unrealized_pnl.rs

@@ -6,12 +6,9 @@ use anyhow::Result;
 use diesel::r2d2::ConnectionManager;
 use diesel::r2d2::PooledConnection;
 use diesel::PgConnection;
-use rust_decimal::Decimal;
 use time::OffsetDateTime;
 use trade::bitmex_client::BitmexClient;
 use trade::bitmex_client::Quote;
-use trade::cfd::calculate_pnl;
-use trade::Direction;
 
 pub async fn sync(node: Node) -> Result<()> {
     let mut conn = node.pool.get()?;
@@ -35,34 +32,7 @@ fn sync_position(
     position: &Position,
     quote: Quote,
 ) -> Result<()> {
-    let closing_price = match position.closing_price {
-        None => quote.get_price_for_direction(position.direction.opposite()),
-        Some(closing_price) => {
-            Decimal::try_from(closing_price).expect("f32 closing price to fit into decimal")
-        }
-    };
-
-    let average_entry_price = Decimal::try_from(position.average_entry_price)
-        .context("Failed to convert average entry price to Decimal")?;
-
-    let (long_leverage, short_leverage) = match position.direction {
-        Direction::Long => (position.leverage, 1.0_f32),
-        Direction::Short => (1.0_f32, position.leverage),
-    };
-
-    // the position in the database is the trader's position, our direction is opposite
-    let direction = position.direction.opposite();
-
-    let pnl = calculate_pnl(
-        average_entry_price,
-        closing_price,
-        position.quantity,
-        long_leverage,
-        short_leverage,
-        direction,
-    )
-    .context("Failed to calculate pnl for position")?;
-
+    let pnl = position.calculate_coordinator_pnl(quote)?;
     db::positions::Position::update_unrealized_pnl(conn, position.id, pnl)
         .context("Failed to update unrealized pnl in db")?;
 

coordinator/src/position/models.rs

@@ -1,6 +1,12 @@
+use crate::node::COORDINATOR_LEVERAGE;
+use anyhow::Context;
+use anyhow::Result;
 use bitcoin::secp256k1::PublicKey;
 use dlc_manager::ContractId;
+use rust_decimal::Decimal;
 use time::OffsetDateTime;
+use trade::bitmex_client::Quote;
+use trade::cfd::calculate_pnl;
 use trade::ContractSymbol;
 use trade::Direction;
 
@@ -51,3 +57,196 @@ pub struct Position {
     pub temporary_contract_id: Option<ContractId>,
     pub closing_price: Option<f32>,
 }
+
+impl Position {
+    /// Calculates the profit and loss for the coordinator in satoshis
+    ///
+    /// The position stored represents the values of the trader.
+    pub fn calculate_coordinator_pnl(&self, quote: Quote) -> Result<i64> {
+        let closing_price = match self.closing_price {
+            None => quote.get_price_for_direction(self.direction.opposite()),
+            Some(closing_price) => {
+                Decimal::try_from(closing_price).expect("f32 closing price to fit into decimal")
+            }
+        };
+
+        let average_entry_price = Decimal::try_from(self.average_entry_price)
+            .context("Failed to convert average entry price to Decimal")?;
+
+        let (long_leverage, short_leverage) = match self.direction {
+            Direction::Long => (self.leverage, COORDINATOR_LEVERAGE),
+            Direction::Short => (COORDINATOR_LEVERAGE, self.leverage),
+        };
+
+        // the position in the database is the trader's position, our direction is opposite
+        let direction = self.direction.opposite();
+
+        let pnl = calculate_pnl(
+            average_entry_price,
+            closing_price,
+            self.quantity,
+            long_leverage,
+            short_leverage,
+            direction,
+        )
+        .context("Failed to calculate pnl for position")?;
+
+        Ok(pnl)
+    }
+}
+
+#[cfg(test)]
+pub mod tests {
+    use super::*;
+    use std::str::FromStr;
+
+    #[test]
+    fn given_trader_long_position_when_no_bid_price_change_then_zero_pnl() {
+        let position = Position::dummy()
+            .with_leverage(2.0)
+            .with_quantity(1.0)
+            .with_average_entry_price(1000.0)
+            .with_direction(Direction::Long);
+
+        let quote = dummy_quote(1000, 0);
+
+        let coordinator_pnl = position.calculate_coordinator_pnl(quote).unwrap();
+
+        assert_eq!(coordinator_pnl, 0);
+    }
+
+    #[test]
+    fn given_trader_short_position_when_no_ask_price_change_then_zero_pnl() {
+        let position = Position::dummy()
+            .with_leverage(2.0)
+            .with_quantity(1.0)
+            .with_average_entry_price(1000.0)
+            .with_direction(Direction::Short);
+
+        let quote = dummy_quote(0, 1000);
+
+        let coordinator_pnl = position.calculate_coordinator_pnl(quote).unwrap();
+
+        assert_eq!(coordinator_pnl, 0);
+    }
+
+    /// See also: `given_long_position_when_price_10_pc_up_then_18pc_profit` test in `trade::cfd`
+    #[test]
+    fn given_trader_long_position_when_bid_price_10pc_up_then_coordinator_18pc_loss() {
+        let position = Position::dummy()
+            .with_leverage(2.0)
+            .with_quantity(20000.0)
+            .with_average_entry_price(20000.0)
+            .with_direction(Direction::Long);
+
+        let quote = dummy_quote(22000, 0);
+
+        let coordinator_pnl = position.calculate_coordinator_pnl(quote).unwrap();
+
+        assert_eq!(coordinator_pnl, -9_090_909);
+    }
+
+    /// See also: `given_short_position_when_price_10_pc_up_then_18pc_loss` test in `trade::cfd`
+    #[test]
+    fn given_trader_short_position_when_bid_price_10pc_up_then_coordinator_18pc_profit() {
+        let position = Position::dummy()
+            .with_leverage(2.0)
+            .with_quantity(20000.0)
+            .with_average_entry_price(20000.0)
+            .with_direction(Direction::Short);
+
+        let quote = dummy_quote(0, 22000);
+
+        let coordinator_pnl = position.calculate_coordinator_pnl(quote).unwrap();
+
+        assert_eq!(coordinator_pnl, 9_090_909);
+    }
+
+    /// See also: `given_long_position_when_price_10_pc_down_then_22pc_loss` test in `trade::cfd`
+    #[test]
+    fn given_trader_long_position_when_bid_price_10pc_down_then_coordinator_22pc_profit() {
+        let position = Position::dummy()
+            .with_leverage(2.0)
+            .with_quantity(20000.0)
+            .with_average_entry_price(20000.0)
+            .with_direction(Direction::Long);
+
+        let quote = dummy_quote(18000, 0);
+
+        let coordinator_pnl = position.calculate_coordinator_pnl(quote).unwrap();
+
+        assert_eq!(coordinator_pnl, 11_111_111);
+    }
+
+    /// See also: `given_short_position_when_price_10_pc_down_then_22pc_profit` test in `trade::cfd`
+    #[test]
+    fn given_trader_short_position_when_bid_price_10pc_down_then_coordinator_22pc_loss() {
+        let position = Position::dummy()
+            .with_leverage(2.0)
+            .with_quantity(20000.0)
+            .with_average_entry_price(20000.0)
+            .with_direction(Direction::Short);
+
+        let quote = dummy_quote(0, 18000);
+
+        let coordinator_pnl = position.calculate_coordinator_pnl(quote).unwrap();
+
+        assert_eq!(coordinator_pnl, -11_111_111);
+    }
+
+    fn dummy_quote(bid: u64, ask: u64) -> Quote {
+        Quote {
+            bid_size: 0,
+            ask_size: 0,
+            bid_price: Decimal::from(bid),
+            ask_price: Decimal::from(ask),
+            symbol: "".to_string(),
+            timestamp: OffsetDateTime::now_utc(),
+        }
+    }
+
+    impl Position {
+        fn dummy() -> Self {
+            Position {
+                id: 0,
+                contract_symbol: ContractSymbol::BtcUsd,
+                leverage: 2.0,
+                quantity: 100.0,
+                direction: Direction::Long,
+                average_entry_price: 10000.0,
+                liquidation_price: 0.0,
+                position_state: PositionState::Open,
+                collateral: 1000,
+                creation_timestamp: OffsetDateTime::now_utc(),
+                expiry_timestamp: OffsetDateTime::now_utc(),
+                update_timestamp: OffsetDateTime::now_utc(),
+                trader: PublicKey::from_str(
+                    "02bd998ebd176715fe92b7467cf6b1df8023950a4dd911db4c94dfc89cc9f5a655",
+                )
+                .unwrap(),
+                temporary_contract_id: None,
+                closing_price: None,
+            }
+        }
+
+        fn with_quantity(mut self, quantity: f32) -> Self {
+            self.quantity = quantity;
+            self
+        }
+
+        fn with_average_entry_price(mut self, average_entry_price: f32) -> Self {
+            self.average_entry_price = average_entry_price;
+            self
+        }
+
+        fn with_leverage(mut self, leverage: f32) -> Self {
+            self.leverage = leverage;
+            self
+        }
+
+        fn with_direction(mut self, direction: Direction) -> Self {
+            self.direction = direction;
+            self
+        }
+    }
+}