From 9bf31c6929813967aaa5faa67cf6a716fa1c7d29 Mon Sep 17 00:00:00 2001
From: Ammar Arif <evergreenkary@gmail.com>
Date: Wed, 16 Oct 2024 14:41:23 -0400
Subject: [PATCH] fix estimate message fee error

---
 crates/katana/rpc/rpc-types/src/message.rs | 10 ++++++++--
 crates/katana/rpc/rpc/tests/messaging.rs   | 17 ++++++-----------
 2 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/crates/katana/rpc/rpc-types/src/message.rs b/crates/katana/rpc/rpc-types/src/message.rs
index 120ecf28ff..5bb95ffa83 100644
--- a/crates/katana/rpc/rpc-types/src/message.rs
+++ b/crates/katana/rpc/rpc-types/src/message.rs
@@ -13,6 +13,12 @@ impl MsgFromL1 {
         // for the `estimateMessageFee` RPC.
         let nonce = Felt::ZERO;
 
+        // When executing a l1 handler tx, blockifier just assert that the paid_fee_on_l1 is
+        // anything but 0. See: https://github.com/dojoengine/sequencer/blob/d6951f24fc2082c7aa89cdbc063648915b131d74/crates/blockifier/src/transaction/transaction_execution.rs#L140-L145
+        //
+        // For fee estimation, this value is basically irrelevant.
+        let paid_fee_on_l1 = 1u128;
+
         let message_hash = compute_l2_to_l1_message_hash(
             // This conversion will never fail bcs `from_address` is 20 bytes and the it will only
             // fail if the slice is > 32 bytes
@@ -25,9 +31,9 @@ impl MsgFromL1 {
             nonce,
             chain_id,
             message_hash,
-            calldata: self.0.payload,
+            paid_fee_on_l1,
             version: Felt::ZERO,
-            paid_fee_on_l1: Default::default(),
+            calldata: self.0.payload,
             contract_address: self.0.to_address.into(),
             entry_point_selector: self.0.entry_point_selector,
         }
diff --git a/crates/katana/rpc/rpc/tests/messaging.rs b/crates/katana/rpc/rpc/tests/messaging.rs
index 08fcf8fe67..fecc5155c6 100644
--- a/crates/katana/rpc/rpc/tests/messaging.rs
+++ b/crates/katana/rpc/rpc/tests/messaging.rs
@@ -20,10 +20,9 @@ use katana_rpc_types::receipt::ReceiptBlock;
 use rand::Rng;
 use starknet::accounts::{Account, ConnectedAccount};
 use starknet::contract::ContractFactory;
-use starknet::core::types::MsgFromL1;
 use starknet::core::types::{
-    BlockId, BlockTag, ContractClass, Felt, Hash256, Transaction, TransactionFinalityStatus,
-    TransactionReceipt,
+    BlockId, BlockTag, ContractClass, Felt, Hash256, MsgFromL1, Transaction,
+    TransactionFinalityStatus, TransactionReceipt,
 };
 use starknet::core::utils::get_contract_address;
 use starknet::macros::selector;
@@ -331,8 +330,10 @@ async fn estimate_message_fee() -> Result<()> {
     // Compute the contract address of the l1 handler contract
     let l1handler_address = get_contract_address(Felt::ZERO, class_hash, &[], Felt::ZERO);
 
+    // Attempt to estimate the cost of calling a #[l1handler] function
+
     let entry_point_selector = selector!("msg_handler_value");
-    let payload = vec![felt!("0x123"), felt!("123")];
+    let payload = vec![felt!("0x123"), felt!("123")]; // function arguments
     let from_address = felt!("0x1337");
     let to_address = l1handler_address;
 
@@ -344,13 +345,7 @@ async fn estimate_message_fee() -> Result<()> {
     };
 
     let result = provider.estimate_message_fee(msg, BlockId::Tag(BlockTag::Pending)).await;
-
-    match result {
-        Ok(_) => {}
-        Err(e) => {
-            dbg!(e);
-        }
-    }
+    assert!(result.is_ok());
 
     Ok(())
 }