Add comprehensive tests for conference module.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

tests/test_conference.py

@@ -0,0 +1,370 @@
+"""Tests for agenda.conference module."""
+
+import decimal
+import tempfile
+from datetime import date, datetime
+from typing import Any
+
+import pytest
+import yaml
+
+from agenda.conference import Conference, get_list
+from agenda.event import Event
+
+
+class TestConference:
+    """Tests for Conference dataclass."""
+
+    def test_conference_creation_minimal(self) -> None:
+        """Test creating conference with minimal required fields."""
+        conf = Conference(
+            name="PyCon",
+            topic="Python",
+            location="Portland",
+            start=date(2024, 5, 15),
+            end=date(2024, 5, 17),
+        )
+        assert conf.name == "PyCon"
+        assert conf.topic == "Python"
+        assert conf.location == "Portland"
+        assert conf.start == date(2024, 5, 15)
+        assert conf.end == date(2024, 5, 17)
+        assert conf.trip is None
+        assert conf.going is False
+        assert conf.online is False
+
+    def test_conference_creation_full(self) -> None:
+        """Test creating conference with all fields."""
+        conf = Conference(
+            name="PyCon US",
+            topic="Python",
+            location="Portland",
+            start=date(2024, 5, 15),
+            end=date(2024, 5, 17),
+            trip=date(2024, 5, 14),
+            country="USA",
+            venue="Convention Center",
+            address="123 Main St",
+            url="https://pycon.org",
+            accommodation_booked=True,
+            transport_booked=True,
+            going=True,
+            registered=True,
+            speaking=True,
+            online=False,
+            price=decimal.Decimal("500.00"),
+            currency="USD",
+            latitude=45.5152,
+            longitude=-122.6784,
+            cfp_end=date(2024, 2, 1),
+            cfp_url="https://pycon.org/cfp",
+            free=False,
+            hackathon=True,
+            ticket_type="early_bird",
+            attendees=3000,
+            hashtag="#pycon2024",
+        )
+        assert conf.name == "PyCon US"
+        assert conf.going is True
+        assert conf.price == decimal.Decimal("500.00")
+        assert conf.currency == "USD"
+        assert conf.latitude == 45.5152
+        assert conf.longitude == -122.6784
+        assert conf.cfp_end == date(2024, 2, 1)
+        assert conf.hashtag == "#pycon2024"
+
+    def test_display_name_location_in_name(self) -> None:
+        """Test display_name when location is already in conference name."""
+        conf = Conference(
+            name="PyCon Portland",
+            topic="Python",
+            location="Portland",
+            start=date(2024, 5, 15),
+            end=date(2024, 5, 17),
+        )
+        assert conf.display_name == "PyCon Portland"
+
+    def test_display_name_location_not_in_name(self) -> None:
+        """Test display_name when location is not in conference name."""
+        conf = Conference(
+            name="PyCon",
+            topic="Python",
+            location="Portland",
+            start=date(2024, 5, 15),
+            end=date(2024, 5, 17),
+        )
+        assert conf.display_name == "PyCon (Portland)"
+
+    def test_display_name_partial_location_match(self) -> None:
+        """Test display_name when location is partially in name."""
+        conf = Conference(
+            name="PyConf",
+            topic="Python",
+            location="Conference Center",
+            start=date(2024, 5, 15),
+            end=date(2024, 5, 17),
+        )
+        assert conf.display_name == "PyConf (Conference Center)"
+
+    def test_conference_with_datetime(self) -> None:
+        """Test conference with datetime objects."""
+        start_dt = datetime(2024, 5, 15, 9, 0)
+        end_dt = datetime(2024, 5, 17, 17, 0)
+        conf = Conference(
+            name="PyCon",
+            topic="Python",
+            location="Portland",
+            start=start_dt,
+            end=end_dt,
+        )
+        assert conf.start == start_dt
+        assert conf.end == end_dt
+
+
+class TestGetList:
+    """Tests for get_list function."""
+
+    def test_get_list_single_conference(self) -> None:
+        """Test reading single conference from YAML."""
+        yaml_data = [
+            {
+                "name": "PyCon",
+                "topic": "Python",
+                "location": "Portland",
+                "start": date(2024, 5, 15),
+                "end": date(2024, 5, 17),
+                "url": "https://pycon.org",
+                "going": True,
+            }
+        ]
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump(yaml_data, f)
+            f.flush()
+
+            events = get_list(f.name)
+
+        assert len(events) == 1
+        event = events[0]
+        assert isinstance(event, Event)
+        assert event.name == "conference"
+        assert event.date == date(2024, 5, 15)
+        assert event.end_date == date(2024, 5, 17)
+        assert event.title == "PyCon (Portland)"
+        assert event.url == "https://pycon.org"
+        assert event.going is True
+
+    def test_get_list_conference_with_cfp(self) -> None:
+        """Test reading conference with CFP end date."""
+        yaml_data = [
+            {
+                "name": "PyCon",
+                "topic": "Python",
+                "location": "Portland",
+                "start": date(2024, 5, 15),
+                "end": date(2024, 5, 17),
+                "url": "https://pycon.org",
+                "cfp_end": date(2024, 2, 1),
+                "cfp_url": "https://pycon.org/cfp",
+            }
+        ]
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump(yaml_data, f)
+            f.flush()
+
+            events = get_list(f.name)
+
+        assert len(events) == 2
+
+        # Conference event
+        conf_event = events[0]
+        assert conf_event.name == "conference"
+        assert conf_event.title == "PyCon (Portland)"
+        assert conf_event.url == "https://pycon.org"
+
+        # CFP end event
+        cfp_event = events[1]
+        assert cfp_event.name == "cfp_end"
+        assert cfp_event.date == date(2024, 2, 1)
+        assert cfp_event.title == "CFP end: PyCon (Portland)"
+        assert cfp_event.url == "https://pycon.org/cfp"
+
+    def test_get_list_conference_cfp_no_url(self) -> None:
+        """Test reading conference with CFP end date but no CFP URL."""
+        yaml_data = [
+            {
+                "name": "PyCon",
+                "topic": "Python",
+                "location": "Portland",
+                "start": date(2024, 5, 15),
+                "end": date(2024, 5, 17),
+                "url": "https://pycon.org",
+                "cfp_end": date(2024, 2, 1),
+            }
+        ]
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump(yaml_data, f)
+            f.flush()
+
+            events = get_list(f.name)
+
+        assert len(events) == 2
+        cfp_event = events[1]
+        assert cfp_event.url == "https://pycon.org"  # Falls back to conference URL
+
+    def test_get_list_multiple_conferences(self) -> None:
+        """Test reading multiple conferences from YAML."""
+        yaml_data = [
+            {
+                "name": "PyCon",
+                "topic": "Python",
+                "location": "Portland",
+                "start": date(2024, 5, 15),
+                "end": date(2024, 5, 17),
+            },
+            {
+                "name": "EuroPython",
+                "topic": "Python",
+                "location": "Prague",
+                "start": date(2024, 7, 8),
+                "end": date(2024, 7, 14),
+                "cfp_end": date(2024, 3, 15),
+            },
+        ]
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump(yaml_data, f)
+            f.flush()
+
+            events = get_list(f.name)
+
+        assert len(events) == 3  # 2 conferences + 1 CFP end
+
+        # First conference
+        assert events[0].title == "PyCon (Portland)"
+        assert events[0].date == date(2024, 5, 15)
+
+        # Second conference
+        assert events[1].title == "EuroPython (Prague)"
+        assert events[1].date == date(2024, 7, 8)
+
+        # CFP end event for second conference
+        assert events[2].name == "cfp_end"
+        assert events[2].title == "CFP end: EuroPython (Prague)"
+
+    def test_get_list_location_in_name(self) -> None:
+        """Test conference where location is already in name."""
+        yaml_data = [
+            {
+                "name": "PyCon Portland",
+                "topic": "Python",
+                "location": "Portland",
+                "start": date(2024, 5, 15),
+                "end": date(2024, 5, 17),
+            }
+        ]
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump(yaml_data, f)
+            f.flush()
+
+            events = get_list(f.name)
+
+        assert len(events) == 1
+        assert events[0].title == "PyCon Portland"  # No location appended
+
+    def test_get_list_datetime_objects(self) -> None:
+        """Test reading conferences with datetime objects."""
+        yaml_data = [
+            {
+                "name": "PyCon",
+                "topic": "Python",
+                "location": "Portland",
+                "start": datetime(2024, 5, 15, 9, 0),
+                "end": datetime(2024, 5, 17, 17, 0),
+            }
+        ]
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump(yaml_data, f)
+            f.flush()
+
+            events = get_list(f.name)
+
+        assert len(events) == 1
+        event = events[0]
+        assert event.date == datetime(2024, 5, 15, 9, 0)
+        assert event.end_date == datetime(2024, 5, 17, 17, 0)
+
+    def test_get_list_invalid_date_order(self) -> None:
+        """Test that conferences with end before start raise assertion error."""
+        yaml_data = [
+            {
+                "name": "Invalid Conference",
+                "topic": "Testing",
+                "location": "Nowhere",
+                "start": date(2024, 5, 17),
+                "end": date(2024, 5, 15),  # End before start
+            }
+        ]
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump(yaml_data, f)
+            f.flush()
+
+            with pytest.raises(AssertionError):
+                get_list(f.name)
+
+    def test_get_list_too_long_conference(self) -> None:
+        """Test that conferences longer than MAX_CONF_DAYS raise assertion error."""
+        yaml_data = [
+            {
+                "name": "Too Long Conference",
+                "topic": "Testing",
+                "location": "Nowhere",
+                "start": date(2024, 5, 1),
+                "end": date(2024, 6, 1),  # More than 20 days
+            }
+        ]
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump(yaml_data, f)
+            f.flush()
+
+            with pytest.raises(AssertionError):
+                get_list(f.name)
+
+    def test_get_list_empty_file(self) -> None:
+        """Test reading empty YAML file."""
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump([], f)
+            f.flush()
+
+            events = get_list(f.name)
+
+        assert events == []
+
+    def test_get_list_same_day_conference(self) -> None:
+        """Test conference that starts and ends on same day."""
+        yaml_data = [
+            {
+                "name": "One Day Conference",
+                "topic": "Testing",
+                "location": "Test City",
+                "start": date(2024, 5, 15),
+                "end": date(2024, 5, 15),
+            }
+        ]
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            yaml.dump(yaml_data, f)
+            f.flush()
+
+            events = get_list(f.name)
+
+        assert len(events) == 1
+        event = events[0]
+        assert event.date == date(2024, 5, 15)
+        assert event.end_date == date(2024, 5, 15)

tests/test_gwr.py

@@ -0,0 +1,208 @@
+"""Tests for agenda.gwr module."""
+
+import os
+import tempfile
+from datetime import date
+from typing import Any
+from unittest.mock import AsyncMock, patch
+
+import pytest
+
+from agenda.gwr import (
+    advance_ticket_date,
+    advance_tickets_page_html,
+    extract_dates,
+    extract_weekday_date,
+    parse_date_string,
+)
+
+
+class TestParseDateString:
+    """Tests for parse_date_string function."""
+
+    def test_parse_date_with_year(self) -> None:
+        """Test parsing date string with year included."""
+        result = parse_date_string("Monday 25 December 2023")
+        assert result == date(2023, 12, 25)
+
+    def test_parse_date_without_year(self) -> None:
+        """Test parsing date string without year (should use current year)."""
+        current_year = date.today().year
+        result = parse_date_string("Monday 25 December")
+        assert result == date(current_year, 12, 25)
+
+    def test_parse_different_formats(self) -> None:
+        """Test parsing various date formats."""
+        result = parse_date_string("Friday 1 January 2024")
+        assert result == date(2024, 1, 1)
+
+        result = parse_date_string("Saturday 29 February 2024")
+        assert result == date(2024, 2, 29)
+
+
+class TestExtractDates:
+    """Tests for extract_dates function."""
+
+    def test_extract_valid_dates(self) -> None:
+        """Test extracting dates from valid HTML."""
+        html = """
+        <tr><td>Weekdays</td><td>Monday 25 December 2023</td></tr>
+        <tr><td>Saturdays</td><td>Saturday 23 December 2023</td></tr>
+        <tr><td>Sundays</td><td>Sunday 24 December 2023</td></tr>
+        """
+        result = extract_dates(html)
+        expected = {
+            "Weekdays": date(2023, 12, 25),
+            "Saturdays": date(2023, 12, 23),
+            "Sundays": date(2023, 12, 24),
+        }
+        assert result == expected
+
+    def test_extract_dates_with_asterisks(self) -> None:
+        """Test extracting dates when HTML contains asterisks."""
+        html = """
+        <tr><td>Weekdays</td><td>Monday 25 December 2023**</td></tr>
+        """
+        result = extract_dates(html)
+        expected = {"Weekdays": date(2023, 12, 25)}
+        assert result == expected
+
+    def test_extract_dates_no_match(self) -> None:
+        """Test extracting dates when no pattern matches."""
+        html = "<p>No relevant table data here</p>"
+        result = extract_dates(html)
+        assert result is None
+
+    def test_extract_dates_whitespace_handling(self) -> None:
+        """Test extracting dates with various whitespace."""
+        html = """
+        <tr>  <td>Weekdays</td>  <td>Monday 25 December 2023</td>  </tr>
+        """
+        result = extract_dates(html)
+        expected = {"Weekdays": date(2023, 12, 25)}
+        assert result == expected
+
+
+class TestExtractWeekdayDate:
+    """Tests for extract_weekday_date function."""
+
+    def test_extract_valid_weekday_date(self) -> None:
+        """Test extracting weekday date from valid HTML."""
+        html = """
+        <tr><td>Weekdays</td><td>Monday 25 December 2023</td></tr>
+        """
+        result = extract_weekday_date(html)
+        assert result == date(2023, 12, 25)
+
+    def test_extract_weekday_date_with_asterisks(self) -> None:
+        """Test extracting weekday date when HTML contains asterisks."""
+        html = """
+        <tr><td>Weekdays</td><td>Monday 25 December 2023**</td></tr>
+        """
+        result = extract_weekday_date(html)
+        assert result == date(2023, 12, 25)
+
+    def test_extract_weekday_date_no_match(self) -> None:
+        """Test extracting weekday date when no pattern matches."""
+        html = "<p>No weekday data here</p>"
+        result = extract_weekday_date(html)
+        assert result is None
+
+    def test_extract_weekday_date_multiline(self) -> None:
+        """Test extracting weekday date with multiline content."""
+        html = """
+        <tr>
+            <td>Weekdays</td>
+            <td>Monday 25 December 2023</td>
+        </tr>
+        """
+        result = extract_weekday_date(html)
+        assert result == date(2023, 12, 25)
+
+
+class TestAdvanceTicketsPageHtml:
+    """Tests for advance_tickets_page_html function."""
+
+    @pytest.mark.asyncio
+    async def test_cache_hit(self) -> None:
+        """Test using cached HTML when file is fresh."""
+        with tempfile.TemporaryDirectory() as temp_dir:
+            cache_file = os.path.join(temp_dir, "advance-tickets.html")
+            test_content = "<html>test content</html>"
+
+            # Create a fresh cache file
+            with open(cache_file, "w") as f:
+                f.write(test_content)
+
+            result = await advance_tickets_page_html(temp_dir, ttl=3600)
+            assert result == test_content
+
+    @pytest.mark.asyncio
+    async def test_force_cache(self) -> None:
+        """Test forcing cache usage even when file doesn't exist."""
+        with tempfile.TemporaryDirectory() as temp_dir:
+            cache_file = os.path.join(temp_dir, "advance-tickets.html")
+            test_content = "<html>cached content</html>"
+
+            with open(cache_file, "w") as f:
+                f.write(test_content)
+
+            result = await advance_tickets_page_html(temp_dir, force_cache=True)
+            assert result == test_content
+
+    @pytest.mark.asyncio
+    @patch("httpx.AsyncClient")
+    async def test_fetch_from_web(self, mock_client: Any) -> None:
+        """Test fetching from web when cache is stale."""
+        mock_response = AsyncMock()
+        mock_response.text = "<html>fresh content</html>"
+        mock_client.return_value.__aenter__.return_value.get.return_value = (
+            mock_response
+        )
+
+        with tempfile.TemporaryDirectory() as temp_dir:
+            result = await advance_tickets_page_html(temp_dir, ttl=0)
+            assert result == "<html>fresh content</html>"
+
+            # Check that content was cached
+            cache_file = os.path.join(temp_dir, "advance-tickets.html")
+            with open(cache_file) as f:
+                cached_content = f.read()
+            assert cached_content == "<html>fresh content</html>"
+
+
+class TestAdvanceTicketDate:
+    """Tests for advance_ticket_date function."""
+
+    @pytest.mark.asyncio
+    @patch("agenda.gwr.advance_tickets_page_html")
+    async def test_advance_ticket_date_success(self, mock_html: Any) -> None:
+        """Test successfully extracting advance ticket date."""
+        mock_html.return_value = """
+        <tr><td>Weekdays</td><td>Monday 25 December 2023</td></tr>
+        """
+
+        result = await advance_ticket_date("/fake/dir")
+        assert result == date(2023, 12, 25)
+        mock_html.assert_called_once_with("/fake/dir", force_cache=False)
+
+    @pytest.mark.asyncio
+    @patch("agenda.gwr.advance_tickets_page_html")
+    async def test_advance_ticket_date_no_match(self, mock_html: Any) -> None:
+        """Test when no weekday date can be extracted."""
+        mock_html.return_value = "<p>No relevant data</p>"
+
+        result = await advance_ticket_date("/fake/dir")
+        assert result is None
+
+    @pytest.mark.asyncio
+    @patch("agenda.gwr.advance_tickets_page_html")
+    async def test_advance_ticket_date_force_cache(self, mock_html: Any) -> None:
+        """Test advance_ticket_date with force_cache parameter."""
+        mock_html.return_value = """
+        <tr><td>Weekdays</td><td>Tuesday 26 December 2023</td></tr>
+        """
+
+        result = await advance_ticket_date("/fake/dir", force_cache=True)
+        assert result == date(2023, 12, 26)
+        mock_html.assert_called_once_with("/fake/dir", force_cache=True)

validate_yaml.py

@@ -4,7 +4,7 @@
 import os
 import sys
 import typing
-from datetime import date, timedelta
+from datetime import date, timedelta, datetime
 
 import yaml
 from rich.pretty import pprint
@@ -33,7 +33,26 @@ def check_currency(item: agenda.types.StrDict) -> None:
 
 
 def check_trips() -> None:
-    """Check trips."""
+    """Check trips and ensure they are in chronological order."""
+    filepath = os.path.join(data_dir, "trips.yaml")
+    trips_data = yaml.safe_load(open(filepath, "r"))
+
+    prev_trip = None
+    prev_trip_data = None
+    for trip_data in trips_data:
+        current_trip = normalize_datetime(trip_data["trip"])
+        if prev_trip and current_trip < prev_trip:
+            print(f"Out of order trip found:")
+            print(
+                f"  Previous: {prev_trip_data.get('trip')} - {prev_trip_data.get('name', 'No name')}"
+            )
+            print(
+                f"  Current:  {trip_data.get('trip')} - {trip_data.get('name', 'No name')}"
+            )
+            assert False, "Trips are not in chronological order by trip date."
+        prev_trip = current_trip
+        prev_trip_data = trip_data
+
     trip_list = agenda.trip.build_trip_list(data_dir)
     print(len(trip_list), "trips")
 
@@ -76,25 +95,68 @@ def check_flights(airlines: set[str]) -> None:
     )
 
 
+def normalize_datetime(dt_value):
+    """Convert date or datetime to datetime for comparison, removing timezone info."""
+    if isinstance(dt_value, date) and not isinstance(dt_value, datetime):
+        return datetime.combine(dt_value, datetime.min.time())
+    elif isinstance(dt_value, datetime):
+        # Remove timezone info to allow comparison between naive and aware datetimes
+        return dt_value.replace(tzinfo=None)
+    return dt_value
+
+
 def check_trains() -> None:
-    """Check trains."""
+    """Check trains and ensure they are in chronological order."""
     trains = agenda.travel.parse_yaml("trains", data_dir)
+
+    prev_depart = None
+    prev_train = None
+    for train in trains:
+        current_depart = normalize_datetime(train["depart"])
+        if prev_depart and current_depart < prev_depart:
+            print(f"Out of order train found:")
+            print(
+                f"  Previous: {prev_train.get('depart')} {prev_train.get('from', '')} -> {prev_train.get('to', '')}"
+            )
+            print(
+                f"  Current:  {train.get('depart')} {train.get('from', '')} -> {train.get('to', '')}"
+            )
+            assert False, "Trains are not in chronological order by departure time."
+        prev_depart = current_depart
+        prev_train = train
+
     print(len(trains), "trains")
 
 
 def check_conferences() -> None:
-    """Check conferences."""
+    """Check conferences and ensure they are in chronological order."""
     filepath = os.path.join(data_dir, "conferences.yaml")
-    conferences = [
-        agenda.conference.Conference(**conf)
-        for conf in yaml.safe_load(open(filepath, "r"))
-    ]
-    for conf in conferences:
+    conferences_data = yaml.safe_load(open(filepath, "r"))
+    conferences = [agenda.conference.Conference(**conf) for conf in conferences_data]
+
+    prev_start = None
+    prev_conf_data = None
+    for i, conf_data in enumerate(conferences_data):
+        conf = conferences[i]
         if not conf.currency or conf.currency in currencies:
-            continue
-        pprint(conf)
-        print(f"currency {conf.currency!r} not in {currencies!r}")
-        sys.exit(-1)
+            pass
+        else:
+            pprint(conf)
+            print(f"currency {conf.currency!r} not in {currencies!r}")
+            sys.exit(-1)
+
+        current_start = normalize_datetime(conf_data["start"])
+        if prev_start and current_start < prev_start:
+            print(f"Out of order conference found:")
+            print(
+                f"  Previous: {prev_conf_data.get('start')} - {prev_conf_data.get('name', 'No name')}"
+            )
+            print(
+                f"  Current:  {conf_data.get('start')} - {conf_data.get('name', 'No name')}"
+            )
+            assert False, "Conferences are not in chronological order by start time."
+        prev_start = current_start
+        prev_conf_data = conf_data
 
     print(len(conferences), "conferences")
 
@@ -118,12 +180,14 @@ def check_coordinates(item: agenda.types.StrDict) -> None:
 
 
 def check_accommodation() -> None:
-    """Check accommodation."""
+    """Check accommodation and ensure they are in chronological order."""
     filepath = os.path.join(data_dir, "accommodation.yaml")
     accommodation_list = yaml.safe_load(open(filepath))
 
     required_fields = ["type", "name", "country", "location", "trip", "from", "to"]
 
+    prev_from = None
+    prev_stay = None
     for stay in accommodation_list:
         try:
             assert all(field in stay for field in required_fields)
@@ -134,6 +198,21 @@ def check_accommodation() -> None:
 
         check_currency(stay)
 
+        current_from = normalize_datetime(stay["from"])
+        if prev_from and current_from < prev_from:
+            print(f"Out of order accommodation found:")
+            print(
+                f"  Previous: {prev_stay.get('from')} - {prev_stay.get('name', 'No name')} ({prev_stay.get('location', '')})"
+            )
+            print(
+                f"  Current:  {stay.get('from')} - {stay.get('name', 'No name')} ({stay.get('location', '')})"
+            )
+            assert (
+                False
+            ), "Accommodation is not in chronological order by check-in time."
+        prev_from = current_from
+        prev_stay = stay
+
     print(len(accommodation_list), "stays")
 
 
@@ -157,6 +236,30 @@ def check_stations() -> None:
         assert agenda.get_country(station["country"])
 
 
+def check_ferries() -> None:
+    """Check ferries and ensure they are in chronological order."""
+    ferries = agenda.travel.parse_yaml("ferries", data_dir)
+
+    prev_depart = None
+    prev_ferry = None
+    for ferry in ferries:
+        current_depart = normalize_datetime(ferry["depart"])
+        if prev_depart and current_depart < prev_depart:
+            print(f"Out of order ferry found:")
+            print(
+                f"  Previous: {prev_ferry.get('depart')} {prev_ferry.get('from', '')} -> {prev_ferry.get('to', '')}"
+            )
+            print(
+                f"  Current:  {ferry.get('depart')} {ferry.get('from', '')} -> {ferry.get('to', '')}"
+            )
+            assert False, "Ferries are not in chronological order by departure time."
+        prev_depart = current_depart
+        prev_ferry = ferry
+        check_currency(ferry)
+
+    print(len(ferries), "ferries")
+
+
 def check_airlines() -> list[agenda.types.StrDict]:
     """Check airlines."""
     airlines = agenda.travel.parse_yaml("airlines", data_dir)
@@ -185,6 +288,7 @@ def check() -> None:
     check_trips()
     check_flights({airline["iata"] for airline in airlines})
     check_trains()
+    check_ferries()
     check_conferences()
     check_events()
     check_accommodation()