Add tests for utility functions

agenda/utils.py

@@ -2,10 +2,8 @@
 
 from datetime import date, datetime, timezone
 
-DateOrDateTime = datetime | date
 
-
-def as_date(d: DateOrDateTime) -> date:
+def as_date(d: datetime | date) -> date:
     """Convert datetime to date."""
     match d:
         case datetime():
@@ -16,7 +14,7 @@ def as_date(d: DateOrDateTime) -> date:
             raise TypeError(f"Unsupported type: {type(d)}")
 
 
-def as_datetime(d: DateOrDateTime) -> datetime:
+def as_datetime(d: datetime | date) -> datetime:
     """Date/time of event."""
     match d:
         case datetime():
@@ -51,10 +49,10 @@ def human_readable_delta(future_date: date) -> str | None:
     # Formatting the output
     parts = []
     if months > 0:
-        parts.append(f"{months} months")
+        parts.append(f"{months} month{'s' if months > 1 else ''}")
     if weeks > 0:
-        parts.append(f"{weeks} weeks")
+        parts.append(f"{weeks} week{'s' if weeks > 1 else ''}")
     if days > 0:
-        parts.append(f"{days} days")
+        parts.append(f"{days} day{'s' if days > 1 else ''}")
 
     return " ".join(parts) if parts else None

tests/test_utils.py

@@ -0,0 +1,96 @@
+"""Test utility functions."""
+
+from datetime import date, datetime, timedelta, timezone
+
+import pytest
+from agenda.utils import as_date, as_datetime, human_readable_delta
+from freezegun import freeze_time
+
+
+def test_as_date_with_datetime() -> None:
+    """Test converting a datetime object to a date."""
+    dt = datetime(2024, 7, 7, 12, 0, 0, tzinfo=timezone.utc)
+    result = as_date(dt)
+    assert result == date(2024, 7, 7)
+
+
+def test_as_date_with_date() -> None:
+    """Test passing a date object through as_date."""
+    d = date(2024, 7, 7)
+    result = as_date(d)
+    assert result == d
+
+
+def test_as_date_with_invalid_type() -> None:
+    """Test as_date with an invalid type, expecting a TypeError."""
+    with pytest.raises(TypeError):
+        as_date("2024-07-07")
+
+
+def test_as_datetime_with_datetime() -> None:
+    """Test passing a datetime object through as_datetime."""
+    dt = datetime(2024, 7, 7, 12, 0, 0, tzinfo=timezone.utc)
+    result = as_datetime(dt)
+    assert result == dt
+
+
+def test_as_datetime_with_date() -> None:
+    """Test converting a date object to a datetime."""
+    d = date(2024, 7, 7)
+    result = as_datetime(d)
+    expected = datetime(2024, 7, 7, 0, 0, 0, tzinfo=timezone.utc)
+    assert result == expected
+
+
+def test_as_datetime_with_invalid_type() -> None:
+    """Test as_datetime with an invalid type, expecting a TypeError."""
+    with pytest.raises(TypeError):
+        as_datetime("2024-07-07")
+
+
+@freeze_time("2024-07-01")
+def test_human_readable_delta_future_date() -> None:
+    """Test human_readable_delta with a future date 45 days from today."""
+    future_date = date.today() + timedelta(days=45)
+    result = human_readable_delta(future_date)
+    assert result == "1 month 2 weeks 1 day"
+
+
+@freeze_time("2024-07-01")
+def test_human_readable_delta_today() -> None:
+    """Test human_readable_delta with today's date, expecting None."""
+    today = date.today()
+    result = human_readable_delta(today)
+    assert result is None
+
+
+@freeze_time("2024-07-01")
+def test_human_readable_delta_past_date() -> None:
+    """Test human_readable_delta with a past date, expecting None."""
+    past_date = date.today() - timedelta(days=1)
+    result = human_readable_delta(past_date)
+    assert result is None
+
+
+@freeze_time("2024-07-01")
+def test_human_readable_delta_months_only() -> None:
+    """Test human_readable_delta with a future date 60 days from today."""
+    future_date = date.today() + timedelta(days=60)
+    result = human_readable_delta(future_date)
+    assert result == "2 months"
+
+
+@freeze_time("2024-07-01")
+def test_human_readable_delta_weeks_only() -> None:
+    """Test human_readable_delta with a future date 14 days from today."""
+    future_date = date.today() + timedelta(days=14)
+    result = human_readable_delta(future_date)
+    assert result == "2 weeks"
+
+
+@freeze_time("2024-07-01")
+def test_human_readable_delta_days_only() -> None:
+    """Test human_readable_delta with a future date 3 days from today."""
+    future_date = date.today() + timedelta(days=3)
+    result = human_readable_delta(future_date)
+    assert result == "3 days"