fix(chats): escape regex in search highlight and fix repr'd output (gptme#1557)

* fix(chats): escape regex in search highlight and fix repr'd output

Two bugs in _format_message_with_context:
1. re.sub used raw query without re.escape, crashing on regex
   metacharacters like (, ), [, +, *, .
2. !r in f-string wrapped matched text in quotes (e.g. 'python'
   instead of python)

Also add re.IGNORECASE for consistent case-insensitive highlighting.

* fix(chats): remove redundant re.DOTALL flag and strengthen test assertion

---------

Co-authored-by: TimeToBuildBob <TimeToBuildBob@users.noreply.github.com>

Author: TimeToBuildBob

gptme/tools/chats.py

@@ -170,15 +170,12 @@ def _format_message_with_context(
         context_suffix = context[match_end:].split("\n", 1)[0]
         context = f"{context_prefix}{context[match_start:match_end]}{context_suffix}"
 
-        # highlighted = f"{prefix}{context_prefix}\033[1m{context[match_start:match_end]}\033[0m{context_suffix}{suffix}"
         highlighted = f"{prefix}{context}{suffix}"
         highlighted = re.sub(
-            query,
-            lambda m: (
-                f"\033[1;31m{m.group(0)!r}\033[0m"
-            ),  # not sure why !r is needed to avoid linting error
+            re.escape(query),
+            lambda m: f"\033[1;31m{m.group(0)}\033[0m",
             highlighted,
-            flags=re.DOTALL,
+            flags=re.IGNORECASE,
         )
         formatted_matches.append(highlighted)
 

tests/test_tools_chats.py

@@ -1,5 +1,5 @@
 from gptme.tools import init_tools
-from gptme.tools.chats import list_chats, search_chats
+from gptme.tools.chats import _format_message_with_context, list_chats, search_chats
 
 
 def test_chats(capsys):
@@ -15,3 +15,42 @@ def test_chats(capsys):
         search_chats("python", system=True)
         captured = capsys.readouterr()
         assert "Search results" in captured.out
+
+
+def test_format_message_basic():
+    """Test basic match highlighting."""
+    result = _format_message_with_context("hello world", "world")
+    assert "world" in result
+    # Should contain ANSI bold red escape codes
+    assert "\033[1;31m" in result
+
+
+def test_format_message_no_match():
+    """Test fallback when no match found."""
+    result = _format_message_with_context("hello world", "xyz")
+    assert result == "hello world"
+
+
+def test_format_message_regex_special_chars():
+    """Test that regex special characters in query don't crash."""
+    # These all contain regex metacharacters
+    for query in ["myFunc(", "file.txt", "a+b", "foo[0]", "x*y", "a|b"]:
+        content = f"some text with {query} in it"
+        result = _format_message_with_context(content, query)
+        assert query in result
+
+
+def test_format_message_no_repr_quotes():
+    """Test that matches are not wrapped in repr quotes."""
+    result = _format_message_with_context("hello world", "world")
+    # Should NOT contain repr-style quotes around the match
+    assert "'world'" not in result
+
+
+def test_format_message_case_insensitive_highlight():
+    """Test that highlighting works case-insensitively and preserves original casing."""
+    result = _format_message_with_context("Hello WORLD", "world")
+    # The ANSI highlight should be present
+    assert "\033[1;31m" in result
+    # Original casing must be preserved inside the highlight (not lowercased)
+    assert "WORLD" in result