test: add edge case tests for parse_to_utc in time_utils

Author: tmdeveloper007

testing/backend/unit/test_time_utils_parse_utc_edge_cases.py

@@ -0,0 +1,97 @@
+"""
+Unit tests for edge cases in parse_to_utc in backend/secuscan/time_utils.py.
+
+These complement the happy-path tests in test_time_utils.py which cover
+common ISO 8601 formats. This file focuses on malformed inputs, None,
+non-string types, and other edge cases.
+"""
+
+from __future__ import annotations
+
+from datetime import datetime, timezone
+
+import pytest
+
+from backend.secuscan.time_utils import parse_to_utc
+
+
+class TestParseToUtcEdgeCases:
+    """Edge case tests for parse_to_utc."""
+
+    def test_none_returns_none(self):
+        """parse_to_utc(None) returns None without raising."""
+        result = parse_to_utc(None)
+        assert result is None
+
+    def test_empty_string_returns_none(self):
+        """parse_to_utc('') returns None without raising."""
+        result = parse_to_utc("")
+        assert result is None
+
+    def test_whitespace_only_string_returns_none(self):
+        """parse_to_utc('   ') (whitespace only) returns None."""
+        result = parse_to_utc("   ")
+        assert result is None
+
+    def test_garbage_string_returns_none(self):
+        """parse_to_utc('not-a-date') returns None without raising."""
+        result = parse_to_utc("not-a-date")
+        assert result is None
+
+    def test_random_text_returns_none(self):
+        """parse_to_utc('hello world') returns None."""
+        result = parse_to_utc("hello world")
+        assert result is None
+
+    def test_integer_timestamp_returns_utc(self):
+        """parse_to_utc(1762108800) treats the integer as a Unix timestamp."""
+        result = parse_to_utc(1762108800)
+        assert result is not None
+        assert result.tzinfo is not None
+        # 1762108800 is a valid Unix timestamp for 2025-11-02 UTC
+        assert result.year == 2025
+
+    def test_float_timestamp_returns_utc(self):
+        """parse_to_utc(1762108800.5) treats the float as a Unix timestamp."""
+        result = parse_to_utc(1762108800.5)
+        assert result is not None
+        assert result.tzinfo is not None
+
+    def test_now_string_returns_current_time(self):
+        """parse_to_utc('now') returns the current UTC time."""
+        before = datetime.now(timezone.utc)
+        result = parse_to_utc("now")
+        after = datetime.now(timezone.utc)
+        assert result is not None
+        assert result.tzinfo is not None
+        # Result should be between before and after (within a few seconds)
+        assert before <= result <= after or after <= result <= before
+
+    def test_list_input_returns_none(self):
+        """parse_to_utc([1, 2, 3]) converts to string '[1, 2, 3]' which is not a valid date."""
+        result = parse_to_utc([1, 2, 3])
+        assert result is None
+
+    def test_boolean_true_returns_utc_epoch_plus_one_second(self):
+        """parse_to_utc(True) treats True as int(1), i.e. Unix epoch + 1 second."""
+        result = parse_to_utc(True)
+        assert result is not None
+        assert result.tzinfo is not None
+        assert result.year == 1970
+        assert result.month == 1
+        assert result.day == 1
+        assert result.hour == 0
+        assert result.minute == 0
+        assert result.second == 1
+
+    def test_boolean_false_returns_utc_epoch(self):
+        """parse_to_utc(False) treats False as int(0), i.e. Unix epoch (1970-01-01 00:00:00 UTC)."""
+        result = parse_to_utc(False)
+        assert result is not None
+        assert result.tzinfo is not None
+        assert result.year == 1970
+        assert result.month == 1
+        assert result.day == 1
+        assert result.hour == 0
+        assert result.minute == 0
+        assert result.second == 0