feat: add clean shutdown for file watcher thread

aider/io.py

@@ -1,5 +1,6 @@
 import base64
 import os
+import threading
 from collections import defaultdict
 from dataclasses import dataclass
 from datetime import datetime
@@ -360,7 +361,27 @@ class InputOutput:
     ):
         self.rule()
 
-        rel_fnames = list(rel_fnames)
+        # Add a variable to store changed files and create stop event
+        self.changed_files = None
+        stop_event = threading.Event()
+        
+        # Define the watcher thread function
+        def watch_files():
+            try:
+                for changed in watch_source_files(root, stop_event=stop_event):
+                    if changed:
+                        self.changed_files = list(changed)[0]  # Take the first changed file
+                        self.interrupt_input()
+                        break
+            except Exception as e:
+                self.tool_error(f"File watcher error: {e}")
+
+        # Start the watcher thread
+        watcher = threading.Thread(target=watch_files, daemon=True)
+        watcher.start()
+
+        try:
+            rel_fnames = list(rel_fnames)
         show = ""
         if rel_fnames:
             rel_read_only_fnames = [
@@ -437,6 +458,13 @@ class InputOutput:
         print()
         self.user_input(inp)
         return inp
+        
+    finally:
+        # Clean up the watcher thread
+        stop_event.set()
+        watcher.join(timeout=1.0)  # Wait up to 1 second for thread to finish
+        if watcher.is_alive():
+            self.tool_warning("Warning: File watcher thread did not shut down cleanly")
 
     def add_to_input_history(self, inp):
         if not self.input_history_file:

aider/watch.py

@@ -58,13 +58,14 @@ def load_gitignores(gitignore_paths: list[Path]) -> Optional[PathSpec]:
     return PathSpec.from_lines(GitWildMatchPattern, patterns) if patterns else None
 
 
-def watch_source_files(directory: str, gitignores: list[str] = None, ignore_func=None) -> Set[str]:
+def watch_source_files(directory: str, stop_event=None, gitignores: list[str] = None, ignore_func=None) -> Set[str]:
     """
     Watch for changes to source files in the given directory and its subdirectories.
     Returns a set of changed file paths whenever changes are detected.
 
     Args:
         directory: Root directory to watch
+        stop_event: Threading event to signal when to stop watching
         gitignores: List of paths to .gitignore files (optional)
         ignore_func: Optional function that takes a path (relative to watched directory)
                     and returns True if it should be ignored
@@ -92,7 +93,7 @@ def watch_source_files(directory: str, gitignores: list[str] = None, ignore_func
         return is_source_file(path_obj)
 
     # Watch the directory for changes
-    for changes in watch(root, watch_filter=filter_func):
+    for changes in watch(root, watch_filter=filter_func, stop_event=stop_event):
         # Convert the changes to a set of unique file paths
         changed_files = {str(Path(change[1])) for change in changes}
         yield changed_files