Align order costs and rebalance priority with rqalpha

crates/fidc-core/tests/core_rules.rs

@@ -1,3 +1,5 @@
+use std::collections::BTreeMap;
+
 use chrono::NaiveDate;
 use fidc_core::cost::CostModel;
 use fidc_core::rules::EquityRuleHooks;
@@ -74,6 +76,46 @@ fn china_cost_model_switches_stamp_tax_rate_after_2023_08_28() {
     assert!((after.stamp_tax - 50.0).abs() < 1e-9);
 }
 
+#[test]
+fn china_cost_model_tracks_minimum_commission_per_order_id() {
+    let model = ChinaAShareCostModel::default();
+    let mut commission_state = BTreeMap::new();
+
+    let first = model.calculate_with_order_state(
+        d(2024, 1, 3),
+        OrderSide::Buy,
+        1_000.0,
+        Some(7),
+        &mut commission_state,
+    );
+    let second = model.calculate_with_order_state(
+        d(2024, 1, 3),
+        OrderSide::Buy,
+        1_000.0,
+        Some(7),
+        &mut commission_state,
+    );
+    let third = model.calculate_with_order_state(
+        d(2024, 1, 3),
+        OrderSide::Buy,
+        20_000.0,
+        Some(7),
+        &mut commission_state,
+    );
+    let another_order = model.calculate_with_order_state(
+        d(2024, 1, 3),
+        OrderSide::Buy,
+        1_000.0,
+        Some(8),
+        &mut commission_state,
+    );
+
+    assert!((first.commission - 5.0).abs() < 1e-9);
+    assert!(second.commission.abs() < 1e-9);
+    assert!((third.commission - 1.6).abs() < 1e-9);
+    assert!((another_order.commission - 5.0).abs() < 1e-9);
+}
+
 #[test]
 fn china_rule_hooks_block_same_day_sell_under_t_plus_one() {
     let hooks = ChinaEquityRuleHooks;
@@ -107,11 +149,13 @@ fn china_rule_hooks_block_buy_at_limit_up_and_sell_at_limit_down() {
         PriceField::Open,
     );
     assert!(!buy_check.allowed);
-    assert!(buy_check
-        .reason
-        .as_deref()
-        .unwrap_or_default()
-        .contains("upper limit"));
+    assert!(
+        buy_check
+            .reason
+            .as_deref()
+            .unwrap_or_default()
+            .contains("upper limit")
+    );
 
     let sell_check = hooks.can_sell(
         d(2024, 1, 3),
@@ -121,11 +165,13 @@ fn china_rule_hooks_block_buy_at_limit_up_and_sell_at_limit_down() {
         PriceField::Open,
     );
     assert!(!sell_check.allowed);
-    assert!(sell_check
-        .reason
-        .as_deref()
-        .unwrap_or_default()
-        .contains("lower limit"));
+    assert!(
+        sell_check
+            .reason
+            .as_deref()
+            .unwrap_or_default()
+            .contains("lower limit")
+    );
 }
 
 #[test]