program: tests-fee-adjustment-neg-100 (#1656)

* program: tests-fee-adjustment-neg-100

* add HLM field to test

* cargo fmt --

---------

Co-authored-by: Chris Heaney <[email protected]>

Author: 0xbigz

programs/drift/src/math/fees/tests.rs

@@ -346,6 +346,171 @@ mod calculate_fee_for_taker_and_maker {
         assert_eq!(referee_discount, 5000);
     }
 
+    #[test]
+    fn fee_adjustment_free() {
+        let quote_asset_amount = 100 * QUOTE_PRECISION_U64;
+        let taker_stats = UserStats::default();
+        let mut maker_stats = UserStats::default();
+
+        let FillFees {
+            user_fee: taker_fee,
+            maker_rebate,
+            fee_to_market,
+            filler_reward,
+            referee_discount,
+            referrer_reward,
+            ..
+        } = calculate_fee_for_fulfillment_with_match(
+            &taker_stats,
+            &Some(&mut maker_stats),
+            quote_asset_amount,
+            &FeeStructure::test_default(),
+            0,
+            0,
+            0,
+            false,
+            &None,
+            &MarketType::Perp,
+            -100,
+            false,
+        )
+        .unwrap();
+
+        assert_eq!(taker_fee, 0);
+        assert_eq!(maker_rebate, 0);
+        assert_eq!(fee_to_market, 0);
+        assert_eq!(filler_reward, 0);
+        assert_eq!(referrer_reward, 0);
+        assert_eq!(referee_discount, 0);
+
+        let FillFees {
+            user_fee: taker_fee,
+            maker_rebate,
+            fee_to_market,
+            filler_reward,
+            referee_discount,
+            referrer_reward,
+            ..
+        } = calculate_fee_for_fulfillment_with_match(
+            &taker_stats,
+            &Some(&mut maker_stats),
+            quote_asset_amount,
+            &FeeStructure::test_default(),
+            0,
+            0,
+            0,
+            false,
+            &None,
+            &MarketType::Perp,
+            -100,
+            false,
+        )
+        .unwrap();
+
+        assert_eq!(taker_fee, 0);
+        assert_eq!(maker_rebate, 0);
+        assert_eq!(fee_to_market, 0);
+        assert_eq!(filler_reward, 0);
+        assert_eq!(referrer_reward, 0);
+        assert_eq!(referee_discount, 0);
+
+        // test HLM
+        let FillFees {
+            user_fee: taker_fee,
+            maker_rebate,
+            fee_to_market,
+            filler_reward,
+            referee_discount,
+            referrer_reward,
+            ..
+        } = calculate_fee_for_fulfillment_with_match(
+            &taker_stats,
+            &Some(&mut maker_stats),
+            quote_asset_amount,
+            &FeeStructure::test_default(),
+            0,
+            0,
+            0,
+            false,
+            &None,
+            &MarketType::Perp,
+            -100,
+            true,
+        )
+        .unwrap();
+
+        assert_eq!(taker_fee, 0);
+        assert_eq!(maker_rebate, 0);
+        assert_eq!(fee_to_market, 0);
+        assert_eq!(filler_reward, 0);
+        assert_eq!(referrer_reward, 0);
+        assert_eq!(referee_discount, 0);
+
+        // reward referrer
+        let FillFees {
+            user_fee: taker_fee,
+            maker_rebate,
+            fee_to_market,
+            filler_reward,
+            referee_discount,
+            referrer_reward,
+            ..
+        } = calculate_fee_for_fulfillment_with_match(
+            &taker_stats,
+            &Some(&mut maker_stats),
+            quote_asset_amount,
+            &FeeStructure::test_default(),
+            0,
+            0,
+            0,
+            true,
+            &None,
+            &MarketType::Perp,
+            -100,
+            false,
+        )
+        .unwrap();
+
+        assert_eq!(taker_fee, 0);
+        assert_eq!(maker_rebate, 0);
+        assert_eq!(fee_to_market, 0);
+        assert_eq!(filler_reward, 0);
+        assert_eq!(referrer_reward, 0);
+        assert_eq!(referee_discount, 0);
+
+        // reward referrer + filler
+        let FillFees {
+            user_fee: taker_fee,
+            maker_rebate,
+            fee_to_market,
+            filler_reward,
+            referee_discount,
+            referrer_reward,
+            ..
+        } = calculate_fee_for_fulfillment_with_match(
+            &taker_stats,
+            &Some(&mut maker_stats),
+            quote_asset_amount,
+            &FeeStructure::test_default(),
+            0,
+            0,
+            1,
+            true,
+            &None,
+            &MarketType::Perp,
+            -100,
+            false,
+        )
+        .unwrap();
+
+        assert_eq!(taker_fee, 0);
+        assert_eq!(maker_rebate, 0);
+        assert_eq!(fee_to_market, 0);
+        assert_eq!(filler_reward, 0);
+        assert_eq!(referrer_reward, 0);
+        assert_eq!(referee_discount, 0);
+    }
+
     #[test]
     fn high_leverage_mode() {
         let quote_asset_amount = 100 * QUOTE_PRECISION_U64;

programs/drift/src/math/orders/tests.rs

@@ -3639,6 +3639,32 @@ pub mod calculate_limit_price_with_buffer {
             Some(100 * PRICE_PRECISION_U64 + PRICE_PRECISION_U64 / 50 / 4) // 100.005
         );
     }
+
+    #[test]
+    fn test_max_fee_adj() {
+        // Post only ask w fee adjustment
+        let order = Order {
+            post_only: true,
+            direction: PositionDirection::Short,
+            ..Order::default()
+        };
+        let limit_price = Some(100 * PRICE_PRECISION_U64);
+        let fee_tier = FeeTier {
+            maker_rebate_numerator: 2,
+            maker_rebate_denominator: 10000, // 2bps
+            ..FeeTier::default()
+        };
+        let fee_adjustment = -100;
+
+        let limit_price_with_buffer =
+            calculate_limit_price_with_buffer(&order, limit_price, &fee_tier, fee_adjustment)
+                .unwrap();
+
+        assert_eq!(
+            limit_price_with_buffer,
+            Some(100 * PRICE_PRECISION_U64) // 100
+        );
+    }
 }
 
 mod select_margin_type_for_perp_maker {