Use easy duration calculation when possible; improve test code coverage

Author: rlskoeser

src/undate/undate.py

@@ -573,8 +573,15 @@ def duration(self) -> Timedelta | UnDelta:
         if self.precision == DatePrecision.DAY:
             return ONE_DAY
 
-        possible_max_days = set()
+        # if year is known and no values are partially known,
+        # we can calculate a time delta based on earliest + latest
+        if self.known_year and not any(
+            [self.is_partially_known(part) for part in ["year", "month", "day"]]
+        ):
+            #  subtract earliest from latest and add a day to include start day in the count
+            return self.latest - self.earliest + ONE_DAY
 
+        possible_max_days = set()
         # if precision is month and year is unknown,
         # calculate month duration within a single year (not min/max)
         if self.precision == DatePrecision.MONTH:
@@ -600,13 +607,9 @@ def duration(self) -> Timedelta | UnDelta:
 
         # if there is more than one possible value for number of days
         # due to range including lear year / non-leap year, return an uncertain delta
-        if possible_max_days:
-            if len(possible_max_days) > 1:
-                return UnDelta(*possible_max_days)
-            return Timedelta(possible_max_days.pop())
-
-        # otherwise, subtract earliest from latest and add a day to include start day in the count
-        return self.latest - self.earliest + ONE_DAY
+        if len(possible_max_days) > 1:
+            return UnDelta(*possible_max_days)
+        return Timedelta(possible_max_days.pop())
 
     def _missing_digit_minmax(
         self, value: str, min_val: int, max_val: int

tests/test_undate.py

@@ -189,11 +189,12 @@ def test_year_property(self):
         # unset year
         assert Undate(month=12, day=31).year == "XXXX"
 
-        # NOTE: no longer supported to inistalize undate with no date information
+        # NOTE: no longer supported to initialize undate with no date information
         # force method to hit conditional for date precision
-        # some_century = Undate()
-        # some_century.precision = DatePrecision.CENTURY
-        # assert some_century.year is None
+        some_century = Undate(year="X")
+        some_century.initial_values["year"] = None
+        some_century.precision = DatePrecision.CENTURY
+        assert some_century.year is None
 
     def test_month_property(self):
         # one, two digit month
@@ -324,6 +325,9 @@ def test_gt_lt_unknown_years(self):
         assert not some_january >= year100
 
     def test_lt_notimplemented(self):
+        # unsupported type should bail out and return NotImplemented
+        assert Undate(2022).__lt__("foo") == NotImplemented
+
         # how to compare mixed precision where dates overlap?
         # if the second date falls *within* earliest/latest,
         # then it is not clearly less; not implemented?
@@ -356,6 +360,9 @@ def test_lt_notimplemented(self):
     def test_contains(self, date1, date2):
         assert date1 in date2
 
+        # unsupported type should bail out and return NotImplemented
+        assert Undate(2022).__contains__("foo") == NotImplemented
+
     testdata_not_contains = [
         # dates not in range
         (Undate(1980), Undate(2020)),