From db7b699d0facfd10c91d90a7331bf815f7d9bbbe Mon Sep 17 00:00:00 2001
From: Brandon Roberts <brandonjroberts22@gmail.com>
Date: Tue, 12 Mar 2024 19:36:45 -0500
Subject: [PATCH] Reorder stuff inside update state due merge conflict

---
 src/appchain.cairo        | 43 ++++++++++++++++++++-------------------
 tests/test_appchain.cairo |  4 +++-
 2 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/src/appchain.cairo b/src/appchain.cairo
index b512f08..eaf1043 100644
--- a/src/appchain.cairo
+++ b/src/appchain.cairo
@@ -98,7 +98,7 @@ mod appchain {
 
     #[derive(Drop, starknet::Event)]
     struct LogStateTransitionFact {
-        state_transition_fact: felt252,
+        state_transition_fact: u256,
     }
 
     /// Initializes the contract.
@@ -131,37 +131,24 @@ mod appchain {
             self.reentrancy_guard.start();
             self.config.assert_only_owner_or_operator();
 
-            let (current_program_hash, current_config_hash): (felt252, felt252) = self
-                .config
-                .program_info
-                .read();
-
-            let state_transition_fact: felt252 = 0; // Done in another PR.
-            let sharp_fact: u256 = keccak::keccak_u256s_be_inputs(
-                array![current_program_hash.into(), state_transition_fact.into()].span()
-            );
-            assert(
-                IFactRegistryMockDispatcher { contract_address: self.config.get_facts_registry() }
-                    .is_valid(sharp_fact),
-                errors::NO_STATE_TRANSITION_PROOF
-            );
-
-            self.emit(LogStateTransitionFact { state_transition_fact });
-
-            // Perform state update
-            self.state.update(program_output);
-
             // Header size + 2 messages segments len.
             assert(
                 program_output.len() > snos_output::HEADER_SIZE + 2,
                 errors::SNOS_INVALID_PROGRAM_OUTPUT_SIZE
             );
+
+            let (current_program_hash, current_config_hash): (felt252, felt252) = self
+                .config
+                .program_info
+                .read();
+
             let data_availability_fact: DataAvailabilityFact = DataAvailabilityFact {
                 onchain_data_hash, onchain_data_size
             };
             let state_transition_fact: u256 = encode_fact_with_onchain_data(
                 program_output, data_availability_fact
             );
+
             let mut program_output_mut = program_output;
             let program_output_struct: ProgramOutput = Serde::deserialize(ref program_output_mut)
                 .unwrap();
@@ -170,6 +157,20 @@ mod appchain {
                 errors::SNOS_INVALID_CONFIG_HASH
             );
 
+            let sharp_fact: u256 = keccak::keccak_u256s_be_inputs(
+                array![current_program_hash.into(), state_transition_fact].span()
+            );
+            assert(
+                IFactRegistryMockDispatcher { contract_address: self.config.get_facts_registry() }
+                    .is_valid(sharp_fact),
+                errors::NO_STATE_TRANSITION_PROOF
+            );
+
+            self.emit(LogStateTransitionFact { state_transition_fact });
+
+            // Perform state update
+            self.state.update(program_output);
+
             let mut offset = snos_output::HEADER_SIZE;
 
             // TODO(#7): We should update SNOS output to have the messages count
diff --git a/tests/test_appchain.cairo b/tests/test_appchain.cairo
index f4fbe92..0def3e7 100644
--- a/tests/test_appchain.cairo
+++ b/tests/test_appchain.cairo
@@ -201,7 +201,9 @@ fn update_state_ok() {
         block_hash: 2885081770536693045243577840233106668867645710434679941076039698247255604327
     };
 
-    let expected_state_transition_fact = LogStateTransitionFact { state_transition_fact: 0 };
+    let expected_state_transition_fact = LogStateTransitionFact {
+        state_transition_fact: 46788249717714808102005259149255132333881826766484550864206886746454286005112
+    };
 
     _spy
         .assert_emitted(