Enhance git metadata handling and improve change detection logic

- Introduced a new function `getGitMetadata` in `ApiContext` to fetch current git metadata, including new file IDs.
- Updated the `PatchTree.build` function to handle new file IDs, allowing for better differentiation between tracked and untracked files during patch processing.
- Modified the `git_changed_files` function to return both tracked and untracked files, improving accuracy in change detection.
- Enhanced the `App` component to debounce git metadata refreshes, ensuring the UI reflects the latest changes without unnecessary calls.

These changes aim to improve the integration with git and enhance the accuracy of change detection in the application.

src/git.rs

@@ -59,8 +59,23 @@ pub fn git_head_commit(repo_root: &Path) -> Option<String> {
     }
 }
 
-fn git_changed_files(repo_root: &Path, initial_head: Option<&str>) -> Option<HashSet<PathBuf>> {
-    let mut changed = HashSet::new();
+struct ChangedFiles {
+    tracked: HashSet<PathBuf>,
+    untracked: HashSet<PathBuf>,
+}
+
+impl ChangedFiles {
+    fn all(&self) -> HashSet<PathBuf> {
+        self.tracked.union(&self.untracked).cloned().collect()
+    }
+
+    fn is_empty(&self) -> bool {
+        self.tracked.is_empty() && self.untracked.is_empty()
+    }
+}
+
+fn git_changed_files(repo_root: &Path, initial_head: Option<&str>) -> Option<ChangedFiles> {
+    let mut tracked = HashSet::new();
 
     let diff_base = initial_head.unwrap_or("HEAD");
     let diff_output = Command::new("git")
@@ -78,7 +93,7 @@ fn git_changed_files(repo_root: &Path, initial_head: Option<&str>) -> Option<Has
         for line in String::from_utf8_lossy(&diff_output.stdout).lines() {
             let trimmed = line.trim();
             if !trimmed.is_empty() {
-                changed.insert(PathBuf::from(trimmed));
+                tracked.insert(PathBuf::from(trimmed));
             }
         }
     } else {
@@ -88,6 +103,7 @@ fn git_changed_files(repo_root: &Path, initial_head: Option<&str>) -> Option<Has
         );
     }
 
+    let mut untracked = HashSet::new();
     let untracked_output = Command::new("git")
         .args([
             "-C",
@@ -103,16 +119,16 @@ fn git_changed_files(repo_root: &Path, initial_head: Option<&str>) -> Option<Has
         for line in String::from_utf8_lossy(&untracked_output.stdout).lines() {
             let trimmed = line.trim();
             if !trimmed.is_empty() {
-                changed.insert(PathBuf::from(trimmed));
+                untracked.insert(PathBuf::from(trimmed));
             }
         }
     }
 
-    if changed.is_empty() && !diff_output.status.success() {
+    if tracked.is_empty() && untracked.is_empty() && !diff_output.status.success() {
         return None;
     }
 
-    Some(changed)
+    Some(ChangedFiles { tracked, untracked })
 }
 
 #[cfg(test)]
@@ -278,6 +294,7 @@ pub fn compute_git_metadata(
             return GitMetadata {
                 changed_ids: Vec::new(),
                 script_committed_hashes: HashMap::new(),
+                new_file_ids: Vec::new(),
             };
         }
     };
@@ -286,15 +303,19 @@ pub fn compute_git_metadata(
         return GitMetadata {
             changed_ids: Vec::new(),
             script_committed_hashes: HashMap::new(),
+            new_file_ids: Vec::new(),
         };
     }
 
+    let untracked_set = &changed_files.untracked;
+    let all_changed = changed_files.all();
+
     // Brief lock: resolve changed file paths to instance Refs and class names
     let resolved: Vec<ResolvedInstance> = {
         let tree = tree_handle.lock().unwrap();
         let mut result = Vec::new();
 
-        for rel_path in &changed_files {
+        for rel_path in &all_changed {
             let abs_path = repo_root.join(rel_path);
             let canonical_path = std::fs::canonicalize(&abs_path).ok();
 
@@ -322,6 +343,11 @@ pub fn compute_git_metadata(
     }; // Lock released
 
     let changed_ids: Vec<Ref> = resolved.iter().map(|ri| ri.id).collect();
+    let new_file_ids: Vec<Ref> = resolved
+        .iter()
+        .filter(|ri| untracked_set.contains(&ri.rel_path))
+        .map(|ri| ri.id)
+        .collect();
     let mut script_committed_hashes: HashMap<Ref, Vec<String>> = HashMap::new();
 
     #[derive(Clone, Copy)]
@@ -393,6 +419,7 @@ pub fn compute_git_metadata(
     GitMetadata {
         changed_ids,
         script_committed_hashes,
+        new_file_ids,
     }
 }
 
@@ -605,7 +632,8 @@ mod tests {
         fs::write(dir.path().join("script.luau"), "modified").unwrap();
 
         let changed = git_changed_files(dir.path(), None).unwrap();
-        assert!(changed.contains(&PathBuf::from("script.luau")));
+        assert!(changed.tracked.contains(&PathBuf::from("script.luau")));
+        assert!(changed.untracked.is_empty());
     }
 
     #[test]
@@ -618,7 +646,7 @@ mod tests {
         git_stage(dir.path(), "script.luau");
 
         let changed = git_changed_files(dir.path(), None).unwrap();
-        assert!(changed.contains(&PathBuf::from("script.luau")));
+        assert!(changed.tracked.contains(&PathBuf::from("script.luau")));
     }
 
     #[test]
@@ -630,7 +658,8 @@ mod tests {
         fs::write(dir.path().join("new_file.luau"), "new").unwrap();
 
         let changed = git_changed_files(dir.path(), None).unwrap();
-        assert!(changed.contains(&PathBuf::from("new_file.luau")));
+        assert!(changed.untracked.contains(&PathBuf::from("new_file.luau")));
+        assert!(!changed.tracked.contains(&PathBuf::from("new_file.luau")));
     }
 
     #[test]
@@ -642,7 +671,7 @@ mod tests {
         fs::remove_file(dir.path().join("to_delete.luau")).unwrap();
 
         let changed = git_changed_files(dir.path(), None).unwrap();
-        assert!(changed.contains(&PathBuf::from("to_delete.luau")));
+        assert!(changed.tracked.contains(&PathBuf::from("to_delete.luau")));
     }
 
     #[test]
@@ -657,9 +686,12 @@ mod tests {
         fs::write(dir.path().join("untracked.luau"), "brand new").unwrap();
 
         let changed = git_changed_files(dir.path(), None).unwrap();
-        assert!(changed.contains(&PathBuf::from("will_modify.luau")));
-        assert!(changed.contains(&PathBuf::from("untracked.luau")));
-        assert!(!changed.contains(&PathBuf::from("committed.luau")));
+        let all = changed.all();
+        assert!(all.contains(&PathBuf::from("will_modify.luau")));
+        assert!(all.contains(&PathBuf::from("untracked.luau")));
+        assert!(!all.contains(&PathBuf::from("committed.luau")));
+        assert!(changed.tracked.contains(&PathBuf::from("will_modify.luau")));
+        assert!(changed.untracked.contains(&PathBuf::from("untracked.luau")));
     }
 
     #[test]
@@ -670,7 +702,10 @@ mod tests {
 
         let changed = git_changed_files(dir.path(), None);
         assert!(changed.is_some());
-        assert!(changed.unwrap().contains(&PathBuf::from("new.luau")));
+        assert!(changed
+            .unwrap()
+            .untracked
+            .contains(&PathBuf::from("new.luau")));
     }
 
     #[test]
@@ -683,7 +718,7 @@ mod tests {
         fs::write(dir.path().join("src/module.luau"), "modified").unwrap();
 
         let changed = git_changed_files(dir.path(), None).unwrap();
-        assert!(changed.contains(&PathBuf::from("src/module.luau")));
+        assert!(changed.tracked.contains(&PathBuf::from("src/module.luau")));
     }
 
     #[test]
@@ -700,13 +735,13 @@ mod tests {
 
         let without = git_changed_files(dir.path(), None).unwrap();
         assert!(
-            !without.contains(&PathBuf::from("script.luau")),
+            !without.all().contains(&PathBuf::from("script.luau")),
             "without initial_head, committed file should NOT appear"
         );
 
         let with = git_changed_files(dir.path(), Some(&initial_head)).unwrap();
         assert!(
-            with.contains(&PathBuf::from("script.luau")),
+            with.tracked.contains(&PathBuf::from("script.luau")),
             "with initial_head, committed file should appear"
         );
     }

src/web/api.rs

@@ -160,6 +160,7 @@ pub async fn call(
             handle_api_syncback(request, &service, syncback_signal).await
         }
         (&Method::GET, "/api/validate-tree") => service.handle_api_validate_tree().await,
+        (&Method::GET, "/api/git-metadata") => service.handle_api_git_metadata().await,
 
         (_method, path) => msgpack(
             ErrorResponse::not_found(format!("Route not found: {}", path)),
@@ -405,6 +406,18 @@ impl ApiService {
         })
     }
 
+    async fn handle_api_git_metadata(&self) -> Response<Full<Bytes>> {
+        let git_metadata = self.serve_session.git_repo_root().map(|repo_root| {
+            crate::git::compute_git_metadata(
+                &self.serve_session.tree_handle(),
+                repo_root,
+                self.serve_session.initial_head_commit(),
+            )
+        });
+
+        msgpack_ok(&git_metadata)
+    }
+
     /// Read-only tree freshness check for test infrastructure.
     /// Re-snapshots from disk and returns drift counts without applying corrections.
     async fn handle_api_validate_tree(&self) -> Response<Full<Bytes>> {

src/web/interface.rs

@@ -214,6 +214,11 @@ pub struct GitMetadata {
     /// SHA1 hashes of prior versions (git blob format) for changed script instances.
     /// Contains 1-2 hashes per script: HEAD version and staged version (if different).
     pub script_committed_hashes: HashMap<Ref, Vec<String>>,
+    /// Instance IDs whose backing files are untracked in git (truly new files,
+    /// never committed). Used by the plugin to default new-file additions to
+    /// "push" (Atlas) since they can't be "something Studio deleted."
+    #[serde(default)]
+    pub new_file_ids: Vec<Ref>,
 }
 
 /// Response body from /api/rojo