Attach context to instances produced by middleware (#273)

src/snapshot_middleware/lua.rs

@@ -33,7 +33,7 @@ impl SnapshotMiddleware for SnapshotLua {
         }
 
         if entry.is_file() {
-            snapshot_lua_file(vfs, entry)
+            snapshot_lua_file(context, vfs, entry)
         } else {
             // At this point, our entry is definitely a directory!
 
@@ -54,7 +54,11 @@ impl SnapshotMiddleware for SnapshotLua {
 }
 
 /// Core routine for turning Lua files into snapshots.
-fn snapshot_lua_file<F: VfsFetcher>(vfs: &Vfs<F>, entry: &VfsEntry) -> SnapshotInstanceResult {
+fn snapshot_lua_file<F: VfsFetcher>(
+    context: &InstanceContext,
+    vfs: &Vfs<F>,
+    entry: &VfsEntry,
+) -> SnapshotInstanceResult {
     let file_name = entry.path().file_name().unwrap().to_string_lossy();
 
     let (class_name, instance_name) = if let Some(name) = match_trailing(&file_name, ".server.lua")
@@ -89,7 +93,8 @@ fn snapshot_lua_file<F: VfsFetcher>(vfs: &Vfs<F>, entry: &VfsEntry) -> SnapshotI
         .metadata(
             InstanceMetadata::new()
                 .instigating_source(entry.path())
-                .relevant_paths(vec![entry.path().to_path_buf(), meta_path.clone()]),
+                .relevant_paths(vec![entry.path().to_path_buf(), meta_path.clone()])
+                .context(context),
         );
 
     if let Some(meta_entry) = vfs.get(meta_path).with_not_found()? {
@@ -116,7 +121,7 @@ fn snapshot_init<F: VfsFetcher>(
 
     if let Some(init_entry) = vfs.get(init_path).with_not_found()? {
         if let Some(dir_snapshot) = SnapshotDir::from_vfs(context, vfs, folder_entry)? {
-            if let Some(mut init_snapshot) = snapshot_lua_file(vfs, &init_entry)? {
+            if let Some(mut init_snapshot) = snapshot_lua_file(context, vfs, &init_entry)? {
                 if dir_snapshot.class_name != "Folder" {
                     panic!(
                         "init.lua, init.server.lua, and init.client.lua can \