"""Tests for timezone utilities."""
from datetime import UTC, datetime
from chuk_mcp_time.timezone_utils import (
convert_datetime_between_timezones,
find_timezone_transitions,
get_timezone_info_at_datetime,
get_tzdata_version,
list_all_timezones,
)
def test_get_tzdata_version() -> None:
"""Test getting tzdata version."""
version = get_tzdata_version()
assert isinstance(version, str)
assert len(version) > 0
# Should be either a version string or "system" or "unknown"
assert version in ["system", "unknown"] or version[0].isdigit()
def test_get_timezone_info_at_datetime() -> None:
"""Test getting timezone info at a specific datetime."""
# Test with EST (winter time in New York)
dt = datetime(2025, 1, 15, 12, 0, 0, tzinfo=UTC)
info = get_timezone_info_at_datetime("America/New_York", dt)
# EST is UTC-5, so -18000 seconds
assert info.utc_offset_seconds == -18000
assert info.is_dst is False
assert info.abbreviation == "EST"
def test_get_timezone_info_at_datetime_dst() -> None:
"""Test getting timezone info during DST."""
# Test with EDT (summer time in New York)
dt = datetime(2025, 7, 15, 12, 0, 0, tzinfo=UTC)
info = get_timezone_info_at_datetime("America/New_York", dt)
# EDT is UTC-4, so -14400 seconds
assert info.utc_offset_seconds == -14400
assert info.is_dst is True
assert info.abbreviation == "EDT"
def test_get_timezone_info_utc() -> None:
"""Test getting timezone info for UTC."""
dt = datetime(2025, 1, 15, 12, 0, 0, tzinfo=UTC)
info = get_timezone_info_at_datetime("UTC", dt)
assert info.utc_offset_seconds == 0
assert info.is_dst is False
assert info.abbreviation == "UTC"
def test_find_timezone_transitions() -> None:
"""Test finding timezone transitions."""
# Find transitions in America/New_York for 1 year
start = datetime(2025, 1, 1, 0, 0, 0, tzinfo=UTC)
end = datetime(2026, 1, 1, 0, 0, 0, tzinfo=UTC)
transitions = find_timezone_transitions("America/New_York", start, end)
# Should find at least 2 transitions (spring forward, fall back)
assert len(transitions) >= 2
# Check structure of transitions
for t in transitions:
assert isinstance(t.from_datetime, datetime)
assert isinstance(t.utc_offset_seconds, int)
assert isinstance(t.is_dst, bool)
assert isinstance(t.abbreviation, str)
def test_find_timezone_transitions_no_dst() -> None:
"""Test finding transitions for timezone without DST."""
# Arizona doesn't observe DST
start = datetime(2025, 1, 1, 0, 0, 0, tzinfo=UTC)
end = datetime(2026, 1, 1, 0, 0, 0, tzinfo=UTC)
transitions = find_timezone_transitions("America/Phoenix", start, end)
# Should find no transitions or very few
assert len(transitions) <= 1
def test_list_all_timezones() -> None:
"""Test listing all timezones."""
timezones = list_all_timezones()
# Should return many timezones
assert len(timezones) > 100
# Check structure
for tz in timezones[:5]: # Just check first 5
assert isinstance(tz.id, str)
assert tz.country_code is None or isinstance(tz.country_code, str)
assert tz.comment is None or isinstance(tz.comment, str)
assert tz.example_city is None or isinstance(tz.example_city, str)
def test_list_all_timezones_search() -> None:
"""Test listing timezones with search filter."""
timezones = list_all_timezones(search="New_York")
# Should find America/New_York
assert len(timezones) >= 1
assert any(tz.id == "America/New_York" for tz in timezones)
def test_list_all_timezones_search_case_insensitive() -> None:
"""Test that search is case-insensitive."""
timezones_lower = list_all_timezones(search="london")
timezones_upper = list_all_timezones(search="LONDON")
assert len(timezones_lower) == len(timezones_upper)
assert len(timezones_lower) >= 1
def test_list_all_timezones_search_no_results() -> None:
"""Test searching for non-existent timezone."""
timezones = list_all_timezones(search="NonExistentTimezone12345")
assert len(timezones) == 0
def test_convert_datetime_between_timezones() -> None:
"""Test converting datetime between timezones."""
result = convert_datetime_between_timezones(
"2025-06-15T14:00:00", "America/New_York", "Europe/London"
)
assert result.from_timezone == "America/New_York"
assert result.to_timezone == "Europe/London"
assert isinstance(result.from_datetime, datetime)
assert isinstance(result.to_datetime, datetime)
# Check offset values are reasonable
# NYC in June is EDT (UTC-4), London in June is BST (UTC+1)
assert result.from_utc_offset_seconds == -14400 # -4 hours
assert result.to_utc_offset_seconds == 3600 # +1 hour
assert result.offset_difference_seconds == 18000 # 5 hour difference
# Explanation should be present and meaningful
assert "ahead" in result.explanation or "behind" in result.explanation
def test_convert_datetime_winter() -> None:
"""Test converting datetime in winter (standard time)."""
result = convert_datetime_between_timezones(
"2025-01-15T14:00:00", "America/New_York", "Europe/London"
)
# NYC in January is EST (UTC-5), London in January is GMT (UTC+0)
assert result.from_utc_offset_seconds == -18000 # -5 hours
assert result.to_utc_offset_seconds == 0 # UTC+0
assert result.offset_difference_seconds == 18000 # 5 hour difference
def test_convert_datetime_same_timezone() -> None:
"""Test converting within same timezone."""
result = convert_datetime_between_timezones(
"2025-06-15T14:00:00", "America/New_York", "America/New_York"
)
assert result.from_utc_offset_seconds == result.to_utc_offset_seconds
assert result.offset_difference_seconds == 0
assert "same UTC offset" in result.explanation
def test_convert_datetime_to_utc() -> None:
"""Test converting to UTC."""
result = convert_datetime_between_timezones("2025-06-15T14:00:00", "America/New_York", "UTC")
assert result.to_utc_offset_seconds == 0
assert result.from_utc_offset_seconds == -14400 # EDT
def test_convert_datetime_across_date_line() -> None:
"""Test converting across the international date line."""
result = convert_datetime_between_timezones(
"2025-06-15T23:00:00", "America/Los_Angeles", "Asia/Tokyo"
)
# LA to Tokyo crosses date line, should result in next day in Tokyo
from_dt_str = result.from_datetime.isoformat()
to_dt_str = result.to_datetime.isoformat()
# Parse the dates to verify day change
assert "2025-06-15" in from_dt_str
assert "2025-06-16" in to_dt_str # Should be next day in Tokyo
