test(fee): test get_message_segment_length function

crates/blockifier/src/fee/gas_usage_test.rs

@@ -4,6 +4,7 @@ use starknet_api::hash::StarkFelt;
 use starknet_api::stark_felt;
 use starknet_api::transaction::{EventContent, EventData, EventKey, L2ToL1Payload};
 
+use crate::abi::constants;
 use crate::execution::call_info::{
     CallExecution, CallInfo, MessageToL1, OrderedEvent, OrderedL2ToL1Message,
 };
@@ -432,3 +433,26 @@ fn test_onchain_data_discount() {
     assert!(cost_ratio <= 0.9);
     assert!(cost_ratio >= 0.88);
 }
+
+#[rstest]
+#[case(vec![10, 20, 30], Some(50))]
+#[case(vec![10, 20, 30], None)]
+#[case(vec![], Some(50))]
+#[case(vec![], None)]
+fn test_get_message_segment_length(
+    #[case] l2_to_l1_payload_lengths: Vec<usize>,
+    #[case] l1_handler_payload_size: Option<usize>,
+) {
+    let result = get_message_segment_length(&l2_to_l1_payload_lengths, l1_handler_payload_size);
+
+    let expected_result: usize = l2_to_l1_payload_lengths.len()
+        * constants::L2_TO_L1_MSG_HEADER_SIZE
+        + l2_to_l1_payload_lengths.iter().sum::<usize>()
+        + if let Some(size) = l1_handler_payload_size {
+            constants::L1_TO_L2_MSG_HEADER_SIZE + size
+        } else {
+            0
+        };
+
+    assert_eq!(result, expected_result);
+}