Add more type checks and tests

Author: rlskoeser

src/undate/interval.py

@@ -73,6 +73,9 @@ def __repr__(self) -> str:
         return "<UndateInterval %s>" % self
 
     def __eq__(self, other) -> bool:
+        # currently doesn't support comparison with any other types
+        if not isinstance(other, UndateInterval):
+            return NotImplemented
         # consider interval equal if both dates are equal
         return self.earliest == other.earliest and self.latest == other.latest
 

tests/test_interval.py

@@ -82,6 +82,12 @@ def test_eq(self):
         )
         assert UndateInterval(Undate(2022, 5)) == UndateInterval(Undate(2022, 5))
 
+    def test_eq_type_check(self):
+        # doesn't currently support comparison with anything else
+        interval = UndateInterval(Undate(900))
+        # returns NotIplemented if comparison with this type is not supported
+        assert interval.__eq__("foo") == NotImplemented
+
     def test_not_eq(self):
         assert UndateInterval(Undate(2022), Undate(2023)) != UndateInterval(
             Undate(2022), Undate(2024)

tests/test_undate.py

@@ -152,6 +152,10 @@ def test_to_undate(self):
         assert isinstance(undate_from_dt, Undate)
         assert undate_from_dt == Undate(now.year, now.month, now.day)
 
+        # unsupported type
+        with pytest.raises(TypeError):
+            Undate.to_undate("foo")
+
     # test properties for accessing parts of date
     def test_year_property(self):
         # two, three, four five digit years; numeric and string