Refactor .meta.json into AdjacentMetadata type more strongly

src/snapshot_middleware/lua.rs

@@ -94,31 +94,28 @@ fn snapshot_lua_file<F: ImfsFetcher>(
         .path()
         .with_file_name(format!("{}.meta.json", instance_name));
 
-    let mut metadata = InstanceMetadata {
+    let metadata = InstanceMetadata {
         instigating_source: Some(entry.path().to_path_buf().into()),
         relevant_paths: vec![entry.path().to_path_buf(), meta_path.clone()],
         ..Default::default()
     };
 
-    if let Some(meta_entry) = imfs.get(meta_path).with_not_found()? {
+    let mut snapshot = InstanceSnapshot {
-        let meta_contents = meta_entry.contents(imfs)?;
-        let parsed: AdjacentMetadata = serde_json::from_slice(meta_contents)
-            // TODO: Turn into error type
-            .expect(".meta.json file was malformed");
-
-        if let Some(ignore) = parsed.ignore_unknown_instances {
-            metadata.ignore_unknown_instances = ignore;
-        }
-    }
-
-    Ok(Some(InstanceSnapshot {
         snapshot_id: None,
         metadata,
         name: Cow::Owned(instance_name.to_owned()),
         class_name: Cow::Borrowed(class_name),
         properties,
         children: Vec::new(),
-    }))
+    };
+
+    if let Some(meta_entry) = imfs.get(meta_path).with_not_found()? {
+        let meta_contents = meta_entry.contents(imfs)?;
+        let mut metadata = AdjacentMetadata::from_slice(meta_contents);
+        metadata.apply_all(&mut snapshot);
+    }
+
+    Ok(Some(snapshot))
 }
 
 /// Attempts to snapshot an 'init' Lua script contained inside of a folder with

src/snapshot_middleware/meta_file.rs

@@ -1,15 +1,60 @@
+use std::{borrow::Cow, collections::HashMap};
+
+use rbx_dom_weak::UnresolvedRbxValue;
+use rbx_reflection::try_resolve_value;
 use serde::{Deserialize, Serialize};
 
+use crate::snapshot::InstanceSnapshot;
+
 #[derive(Debug, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct AdjacentMetadata {
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub ignore_unknown_instances: Option<bool>,
+    pub class_name: Option<String>,
-}
 
-#[derive(Debug, Serialize, Deserialize)]
-#[serde(rename_all = "camelCase")]
-pub struct InitMetadata {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub ignore_unknown_instances: Option<bool>,
+
+    #[serde(default, skip_serializing_if = "HashMap::is_empty")]
+    pub properties: HashMap<String, UnresolvedRbxValue>,
+}
+
+impl AdjacentMetadata {
+    pub fn from_slice(slice: &[u8]) -> Self {
+        serde_json::from_slice(slice)
+            // TODO: Turn into error type
+            .expect(".meta.json file was malformed")
+    }
+
+    pub fn apply_ignore_unknown_instances(&mut self, snapshot: &mut InstanceSnapshot) {
+        if let Some(ignore) = self.ignore_unknown_instances.take() {
+            snapshot.metadata.ignore_unknown_instances = ignore;
+        }
+    }
+
+    pub fn apply_class_name(&mut self, snapshot: &mut InstanceSnapshot) {
+        if let Some(class_name) = self.class_name.take() {
+            snapshot.class_name = Cow::Owned(class_name);
+        }
+    }
+
+    pub fn apply_properties(&mut self, snapshot: &mut InstanceSnapshot) {
+        let class_name = &snapshot.class_name;
+
+        let source_properties = self.properties.drain().map(|(key, value)| {
+            try_resolve_value(class_name, &key, &value)
+                .map(|resolved| (key, resolved))
+                .expect("TODO: Handle rbx_reflection errors")
+        });
+
+        for (key, value) in source_properties {
+            snapshot.properties.insert(key, value);
+        }
+    }
+
+    pub fn apply_all(&mut self, snapshot: &mut InstanceSnapshot) {
+        self.apply_ignore_unknown_instances(snapshot);
+        self.apply_class_name(snapshot);
+        self.apply_properties(snapshot);
+    }
 }