test: Add comprehensive gitignore pattern tests

aider/watch.py

@@ -17,7 +17,6 @@ def load_gitignores(gitignore_paths: list[Path]) -> Optional[PathSpec]:
     if not gitignore_paths:
         return None
 
-    # AI: add tests for all of these patterns ai!
     patterns = [
         ".aider*",
         ".git",

tests/basic/test_watch.py

@@ -4,6 +4,61 @@ from aider.io import InputOutput
 from aider.watch import FileWatcher
 
 
+def test_gitignore_patterns():
+    """Test that gitignore patterns are properly loaded and matched"""
+    from pathlib import Path
+    from aider.watch import load_gitignores
+
+    # Create a temporary gitignore file with test patterns
+    tmp_gitignore = Path("test.gitignore")
+    tmp_gitignore.write_text("custom_pattern\n*.custom")
+    
+    gitignores = [tmp_gitignore]
+    spec = load_gitignores(gitignores)
+    
+    # Test built-in patterns
+    assert spec.match_file(".aider.conf")
+    assert spec.match_file(".git/config")
+    assert spec.match_file("file~")  # Emacs/vim backup
+    assert spec.match_file("file.bak")
+    assert spec.match_file("file.swp")
+    assert spec.match_file("file.swo")
+    assert spec.match_file("#temp#")  # Emacs auto-save
+    assert spec.match_file(".#lock")  # Emacs lock
+    assert spec.match_file("temp.tmp")
+    assert spec.match_file("temp.temp")
+    assert spec.match_file("conflict.orig")
+    assert spec.match_file("script.pyc")
+    assert spec.match_file("__pycache__/module.pyc")
+    assert spec.match_file(".DS_Store")
+    assert spec.match_file("Thumbs.db")
+    assert spec.match_file(".idea/workspace.xml")
+    assert spec.match_file(".vscode/settings.json")
+    assert spec.match_file("project.sublime-workspace")
+    assert spec.match_file(".project")
+    assert spec.match_file(".settings/config.json")
+    assert spec.match_file("workspace.code-workspace")
+    assert spec.match_file(".env")
+    assert spec.match_file(".venv/bin/python")
+    assert spec.match_file("node_modules/package/index.js")
+    assert spec.match_file("vendor/lib/module.py")
+    assert spec.match_file("debug.log")
+    assert spec.match_file(".cache/files")
+    assert spec.match_file(".pytest_cache/v/cache")
+    assert spec.match_file("coverage/lcov.info")
+    
+    # Test custom patterns from gitignore file
+    assert spec.match_file("custom_pattern")
+    assert spec.match_file("file.custom")
+    
+    # Test non-matching patterns
+    assert not spec.match_file("regular_file.txt")
+    assert not spec.match_file("src/main.py")
+    assert not spec.match_file("docs/index.html")
+    
+    # Cleanup
+    tmp_gitignore.unlink()
+
 def test_ai_comment_pattern():
     # Create minimal IO and Coder instances for testing
     class MinimalCoder: