validator: move function call so get_model_info is infallible

validation/src/check.rs

@@ -127,10 +127,7 @@ pub struct ModelInfo<'a>{
 	counts:Counts,
 }
 
-pub fn get_model_info(dom:&rbx_dom_weak::WeakDom)->Result<ModelInfo,GetRootInstanceError>{
-	// extract the root instance, otherwise immediately return
-	let model_instance=get_root_instance(&dom)?;
-
+pub fn get_model_info<'a>(dom:&'a rbx_dom_weak::WeakDom,model_instance:&'a rbx_dom_weak::Instance)->ModelInfo<'a>{
 	// extract model info
 	let map_info=get_mapinfo(&dom,model_instance);
 
@@ -161,12 +158,12 @@ pub fn get_model_info(dom:&rbx_dom_weak::WeakDom)->Result<ModelInfo,GetRootInsta
 		}
 	}
 
-	Ok(ModelInfo{
+	ModelInfo{
 		model_class:model_instance.class.as_str(),
 		model_name:model_instance.name.as_str(),
 		map_info,
 		counts,
-	})
+	}
 }
 
 // check if an observed string matches an expected string
@@ -515,8 +512,11 @@ impl crate::message_handler::MessageHandler{
 		// decode dom (slow!)
 		let dom=maybe_gzip.read_with(read_dom,read_dom).map_err(Error::ModelFileDecode)?;
 
+		// extract the root instance
+		let model_instance=get_root_instance(&dom).map_err(Error::GetRootInstance)?;
+
 		// extract information from the model
-		let model_info=get_model_info(&dom).map_err(Error::GetRootInstance)?;
+		let model_info=get_model_info(&dom,model_instance);
 
 		// convert the model information into a structured report
 		let map_check=model_info.check();