Add skip_tx hint and test

src/hints/mod.rs

@@ -38,7 +38,7 @@ type HintImpl = fn(
     &HashMap<String, Felt252>,
 ) -> Result<(), HintError>;
 
-static HINTS: [(&str, HintImpl); 53] = [
+static HINTS: [(&str, HintImpl); 54] = [
     // (BREAKPOINT, breakpoint),
     (STARKNET_OS_INPUT, starknet_os_input),
     (INITIALIZE_STATE_CHANGES, initialize_state_changes),
@@ -93,6 +93,7 @@ static HINTS: [(&str, HintImpl); 53] = [
     (IS_ON_CURVE, is_on_curve),
     (IS_N_GE_TWO, is_n_ge_two),
     (START_TX, start_tx),
+    (SKIP_TX, skip_tx),
 ];
 
 /// Hint Extensions extend the current map of hints used by the VM.
@@ -411,8 +412,25 @@ pub fn start_tx(
     let deprecated_tx_info_ptr =
         get_relocatable_from_var_name(vars::ids::DEPRECATED_TX_INFO, vm, ids_data, ap_tracking)?;
 
-    let execution_helper = exec_scopes.get::<ExecutionHelperWrapper>("execution_helper").unwrap();
+    let execution_helper = exec_scopes.get::<ExecutionHelperWrapper>(vars::ids::EXECUTION_HELPER)
+        .unwrap();
     execution_helper.start_tx(Some(deprecated_tx_info_ptr));
 
     Ok(())
 }
+
+const SKIP_TX: &str = "execution_helper.skip_tx()";
+pub fn skip_tx(
+    vm: &mut VirtualMachine,
+    exec_scopes: &mut ExecutionScopes,
+    ids_data: &HashMap<String, HintReference>,
+    ap_tracking: &ApTracking,
+    _constants: &HashMap<String, Felt252>,
+) -> Result<(), HintError> {
+    let execution_helper = exec_scopes.get::<ExecutionHelperWrapper>(vars::ids::EXECUTION_HELPER)
+        .unwrap();
+    execution_helper.skip_tx();
+
+    Ok(())
+}
+

src/hints/tests.rs

@@ -191,4 +191,39 @@ pub(crate) mod tests {
         // after starting tx, tx_execution_info should be some
         assert!(exec_helper_box.execution_helper.borrow().tx_execution_info.is_some());
     }
+
+    #[rstest]
+    fn test_skip_tx(
+        block_context: BlockContext,
+        transaction_execution_info: TransactionExecutionInfo,
+    ) {
+        let mut vm = VirtualMachine::new(false);
+        vm.set_fp(1);
+        vm.add_memory_segment();
+        vm.add_memory_segment();
+
+        let ids_data = ids_data![vars::ids::DEPRECATED_TX_INFO];
+        let ap_tracking = ApTracking::default();
+
+        let mut exec_scopes = ExecutionScopes::new();
+
+        // skipping a tx is the same as starting and immediately ending it, so we need one
+        // execution info to chew through
+        let execution_infos = vec![transaction_execution_info];
+        let exec_helper = ExecutionHelperWrapper::new(execution_infos, &block_context);
+        let exec_helper_box = Box::new(exec_helper);
+        exec_scopes.insert_box(vars::ids::EXECUTION_HELPER, exec_helper_box.clone());
+
+        // before starting tx, tx_execution_info should be none and iter should have a next()
+        assert!(exec_helper_box.execution_helper.borrow().tx_execution_info.is_none());
+        assert!(exec_helper_box.execution_helper.borrow().tx_execution_info_iter.clone().peekable().peek().is_some());
+
+        start_tx(&mut vm, &mut exec_scopes, &ids_data, &ap_tracking, &Default::default())
+            .expect("start_tx");
+
+        // after starting tx, tx_execution_info should be some and iter should not have a next()
+        assert!(exec_helper_box.execution_helper.borrow().tx_execution_info.is_some());
+        assert!(exec_helper_box.execution_helper.borrow().tx_execution_info_iter.clone().peekable().peek().is_none());
+    }
 }
+

src/hints/unimplemented.rs

@@ -224,9 +224,6 @@ const SET_TX_INFO_PTR: &str = indoc! {r#"
 #[allow(unused)]
 const SPLIT_INPUTS_12: &str = "ids.high12, ids.low12 = divmod(memory[ids.inputs + 12], 256 ** 4)";
 
-#[allow(unused)]
-const SKIP_TX: &str = "execution_helper.skip_tx()";
-
 #[allow(unused)]
 const SET_AP_TO_IS_REVERTED: &str =
     "memory[ap] = to_felt_or_relocatable(execution_helper.tx_execution_info.is_reverted)";