test(filters): add tests for --since/--until time filtering

Add comprehensive test coverage for time-based log filtering:
- Test --since filter (exclude logs before time)
- Test --until filter (exclude logs after time)
- Test combined since+until range filtering
- Test entries without timestamps
- Test boundary conditions

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: vinnytherobot

tests/test_filters.py

@@ -1,6 +1,8 @@
 import re
+from datetime import datetime, timedelta
 
-from logscope.viewer import line_passes_level, line_passes_search, parse_level_filter
+from logscope.viewer import line_passes_level, line_passes_search, parse_level_filter, line_passes_filters
+from logscope.parser import LogEntry
 
 
 def test_parse_level_filter_single():
@@ -46,3 +48,76 @@ def test_line_passes_search_invert():
 
 def test_line_passes_search_no_search_always_passes():
     assert line_passes_search("anything", None, pattern=None, use_regex=False, case_sensitive=False, invert_match=True) is True
+
+
+def make_entry(timestamp: datetime, level: str = "INFO", message: str = "test") -> LogEntry:
+    """Helper to create LogEntry for time filter tests."""
+    return LogEntry(level=level, message=message, raw=f"[{level}] {message}", timestamp=timestamp)
+
+
+def test_line_passes_filters_since():
+    """Test that --since filters out entries before the given time."""
+    entry_time = datetime(2026, 4, 5, 10, 0, 0)
+    since_ok = datetime(2026, 4, 5, 9, 0, 0)   # 1 hour before entry
+    since_fail = datetime(2026, 4, 5, 11, 0, 0)  # 1 hour after entry
+
+    entry = make_entry(entry_time)
+
+    assert line_passes_filters(entry, None, None, since_ok, None, pattern=None, use_regex=False, case_sensitive=False, invert_match=False) is True
+    assert line_passes_filters(entry, None, None, since_fail, None, pattern=None, use_regex=False, case_sensitive=False, invert_match=False) is False
+
+
+def test_line_passes_filters_until():
+    """Test that --until filters out entries after the given time."""
+    entry_time = datetime(2026, 4, 5, 10, 0, 0)
+    until_ok = datetime(2026, 4, 5, 11, 0, 0)   # 1 hour after entry
+    until_fail = datetime(2026, 4, 5, 9, 0, 0)  # 1 hour before entry
+
+    entry = make_entry(entry_time)
+
+    assert line_passes_filters(entry, None, None, None, until_ok, pattern=None, use_regex=False, case_sensitive=False, invert_match=False) is True
+    assert line_passes_filters(entry, None, None, None, until_fail, pattern=None, use_regex=False, case_sensitive=False, invert_match=False) is False
+
+
+def test_line_passes_filters_since_until_range():
+    """Test combining --since and --until to create a time range."""
+    entry_time = datetime(2026, 4, 5, 10, 0, 0)
+    since = datetime(2026, 4, 5, 9, 0, 0)
+    until = datetime(2026, 4, 5, 11, 0, 0)
+
+    entry = make_entry(entry_time)
+
+    # Entry within range passes
+    assert line_passes_filters(entry, None, None, since, until, pattern=None, use_regex=False, case_sensitive=False, invert_match=False) is True
+
+    # Entry before range fails
+    entry_early = make_entry(datetime(2026, 4, 5, 8, 0, 0))
+    assert line_passes_filters(entry_early, None, None, since, until, pattern=None, use_regex=False, case_sensitive=False, invert_match=False) is False
+
+    # Entry after range fails
+    entry_late = make_entry(datetime(2026, 4, 5, 12, 0, 0))
+    assert line_passes_filters(entry_late, None, None, since, until, pattern=None, use_regex=False, case_sensitive=False, invert_match=False) is False
+
+
+def test_line_passes_filters_no_timestamp():
+    """Test that entries without timestamp pass time filters."""
+    entry = LogEntry(level="INFO", message="test", raw="[INFO] test", timestamp=None)
+
+    since = datetime(2026, 4, 5, 10, 0, 0)
+    until = datetime(2026, 4, 5, 12, 0, 0)
+
+    # Should pass because no timestamp to filter
+    assert line_passes_filters(entry, None, None, since, None, pattern=None, use_regex=False, case_sensitive=False, invert_match=False) is True
+    assert line_passes_filters(entry, None, None, None, until, pattern=None, use_regex=False, case_sensitive=False, invert_match=False) is True
+
+
+def test_line_passes_filters_exact_boundary():
+    """Test that boundaries are inclusive for --since and exclusive for --until."""
+    entry_time = datetime(2026, 4, 5, 10, 0, 0)
+    entry = make_entry(entry_time)
+
+    # Exact since should pass (inclusive)
+    assert line_passes_filters(entry, None, None, entry_time, None, pattern=None, use_regex=False, case_sensitive=False, invert_match=False) is True
+
+    # Exact until should pass (inclusive)
+    assert line_passes_filters(entry, None, None, None, entry_time, pattern=None, use_regex=False, case_sensitive=False, invert_match=False) is True