Add wait_until_all_staged function to improve file staging checks

- Introduced a new function `wait_until_all_staged` that polls for all specified files to be staged with exponential backoff, enhancing reliability in tests.
- Replaced direct assertions for file staging with calls to `wait_until_all_staged` in multiple test cases, improving test robustness and reducing reliance on fixed sleep durations.

These changes aim to ensure that all files are properly staged before proceeding with assertions, enhancing the accuracy of the tests.

tests/tests/git_sync_defaults.rs

@@ -705,6 +705,32 @@ fn batch_script_rel_path(i: usize) -> String {
     format!("src/{}.luau", batch_script_name(i))
 }
 
+/// Poll until every `rel_paths` entry is staged, with exponential backoff.
+/// Panics after `timeout` if any file is still unstaged.
+fn wait_until_all_staged(dir: &Path, rel_paths: &[String], timeout: Duration) {
+    let start = std::time::Instant::now();
+    let mut interval = Duration::from_millis(200);
+    loop {
+        let all_staged = rel_paths.iter().all(|p| git_is_staged(dir, p));
+        if all_staged {
+            return;
+        }
+        if start.elapsed() >= timeout {
+            for p in rel_paths {
+                if !git_is_staged(dir, p) {
+                    panic!(
+                        "Timed out after {:?} waiting for staging: {} is not staged",
+                        timeout, p
+                    );
+                }
+            }
+            return;
+        }
+        thread::sleep(interval);
+        interval = (interval * 2).min(Duration::from_secs(2));
+    }
+}
+
 #[test]
 fn batch_stage_20_files_no_index_lock_race() {
     let mut session = TestServeSession::new_with_git("git_sync_defaults", |path| {
@@ -741,15 +767,11 @@ fn batch_stage_20_files_no_index_lock_race() {
         stage_ids,
     };
     session.post_api_write(&write_request).unwrap();
-    thread::sleep(Duration::from_millis(1500));
 
-    for i in 1..=BATCH_SCRIPT_COUNT {
-        assert!(
-            git_is_staged(session.path(), &batch_script_rel_path(i)),
-            "{} should be staged",
-            batch_script_name(i)
-        );
-    }
+    let rel_paths: Vec<String> = (1..=BATCH_SCRIPT_COUNT)
+        .map(batch_script_rel_path)
+        .collect();
+    wait_until_all_staged(session.path(), &rel_paths, Duration::from_secs(30));
 }
 
 #[test]
@@ -797,15 +819,14 @@ fn batch_source_write_20_files_all_staged() {
         stage_ids,
     };
     session.post_api_write(&write_request).unwrap();
-    thread::sleep(Duration::from_millis(2000));
+
+    let rel_paths: Vec<String> = (1..=BATCH_SCRIPT_COUNT)
+        .map(batch_script_rel_path)
+        .collect();
+    wait_until_all_staged(session.path(), &rel_paths, Duration::from_secs(30));
 
     for i in 1..=BATCH_SCRIPT_COUNT {
         let rel = batch_script_rel_path(i);
-        assert!(
-            git_is_staged(session.path(), &rel),
-            "{} should be staged after batch Source write",
-            batch_script_name(i)
-        );
         let content = fs::read_to_string(session.path().join(&rel)).unwrap();
         assert!(
             content.contains(&format!("batch pull {}", i)),
@@ -878,16 +899,11 @@ fn batch_mixed_stage_and_source_write() {
         stage_ids,
     };
     session.post_api_write(&write_request).unwrap();
-    thread::sleep(Duration::from_millis(2000));
 
-    // All 20 files should be staged
-    for i in 1..=BATCH_SCRIPT_COUNT {
-        assert!(
-            git_is_staged(session.path(), &batch_script_rel_path(i)),
-            "{} should be staged in mixed batch",
-            batch_script_name(i)
-        );
-    }
+    let rel_paths: Vec<String> = (1..=BATCH_SCRIPT_COUNT)
+        .map(batch_script_rel_path)
+        .collect();
+    wait_until_all_staged(session.path(), &rel_paths, Duration::from_secs(30));
 
     // Files 11-20 should have the new pull content
     for i in 11..=BATCH_SCRIPT_COUNT {