Add test for keyed literal unions -- which fails

databind/src/databind/json/converters.py

@@ -763,7 +763,7 @@ def _check_style_compatibility(self, ctx: Context, style: str, value: t.Any) ->
     def convert(self, ctx: Context) -> t.Any:
         datatype = ctx.datatype
         union: t.Optional[Union]
-        literal_types: list[TypeHint] = []
+        literal_types: t.List[TypeHint] = []
 
         if isinstance(datatype, UnionTypeHint):
             if datatype.has_none_type():

databind/src/databind/json/tests/converters_test.py

@@ -30,6 +30,7 @@
     DatetimeConverter,
     DecimalConverter,
     EnumConverter,
+    LiteralConverter,
     MappingConverter,
     OptionalConverter,
     PlainDatatypeConverter,
@@ -328,6 +329,22 @@ def test_union_converter_best_match(direction: Direction) -> None:
         assert mapper.convert(direction, 42, t.Union[int, str]) == 42
 
 
+@pytest.mark.parametrize("direction", (Direction.SERIALIZE, Direction.DESERIALIZE))
+def test_union_converter_best_match_literal(direction: Direction) -> None:
+    mapper = make_mapper([UnionConverter(), PlainDatatypeConverter(), LiteralConverter()])
+
+    LiteralUnionType = t.Union[int, t.Literal["hi"], t.Literal["bye"]]
+
+    if direction == Direction.DESERIALIZE:
+        assert mapper.convert(direction, 42, LiteralUnionType) == 42
+        assert mapper.convert(direction, "hi", LiteralUnionType) == "hi"
+        assert mapper.convert(direction, "bye", LiteralUnionType) == "bye"
+    else:
+        assert mapper.convert(direction, 42, LiteralUnionType) == 42
+        assert mapper.convert(direction, "hi", LiteralUnionType) == "hi"
+        assert mapper.convert(direction, "bye", LiteralUnionType) == "bye"
+
+
 @pytest.mark.parametrize("direction", (Direction.SERIALIZE, Direction.DESERIALIZE))
 def test_union_converter_keyed(direction: Direction) -> None:
     mapper = make_mapper([UnionConverter(), PlainDatatypeConverter()])
@@ -339,6 +356,31 @@ def test_union_converter_keyed(direction: Direction) -> None:
         assert mapper.convert(direction, 42, th) == {"int": 42}
 
 
+@pytest.mark.xfail
+@pytest.mark.parametrize("direction", (Direction.SERIALIZE, Direction.DESERIALIZE))
+def test_union_converter_keyed_literal(direction: Direction) -> None:
+    mapper = make_mapper([UnionConverter(), PlainDatatypeConverter(), LiteralConverter()])
+
+    th = te.Annotated[
+        t.Union[int, t.Literal["hi"], t.Literal["bye"]],
+        Union({"int": int, "HiType": t.Literal["hi"], "ByeType": t.Literal["bye"]}, style=Union.KEYED),
+    ]
+    if direction == Direction.DESERIALIZE:
+        assert mapper.convert(direction, {"int": 42}, th) == 42
+        assert mapper.convert(direction, {"HiType": "hi"}, th) == "hi"
+        assert mapper.convert(direction, {"ByeType": "bye"}, th) == "bye"
+
+        with pytest.raises(ConversionError):
+            mapper.convert(direction, {"ByeType": "hi"}, th)
+    else:
+        assert mapper.convert(direction, 42, th) == {"int": 42}
+        assert mapper.convert(direction, "hi", th) == {"HiType": "hi"}
+        assert mapper.convert(direction, "bye", th) == {"ByeType": "bye"}
+
+        with pytest.raises(ConversionError):
+            mapper.convert(direction, {"ByeType": "hi"}, th)
+
+
 @pytest.mark.parametrize("direction", (Direction.SERIALIZE, Direction.DESERIALIZE))
 def test_union_converter_flat_plain_types_not_supported(direction: Direction) -> None:
     mapper = make_mapper([UnionConverter(), PlainDatatypeConverter()])
@@ -713,22 +755,3 @@ def of(cls, v: str) -> "MyCls":
     mapper = make_mapper([JsonConverterSupport()])
     assert mapper.serialize(MyCls(), MyCls) == "MyCls"
     assert mapper.deserialize("MyCls", MyCls) == MyCls()
-
-
-def test_union_literal():
-    mapper = make_mapper([UnionConverter(), PlainDatatypeConverter()])
-
-    IntType = int | t.Literal["hi", "bye"]
-    StrType = str | t.Literal["hi", "bye"]
-
-    assert mapper.serialize("hi", IntType) == "hi"
-    assert mapper.serialize(2, IntType) == 2
-
-    assert mapper.serialize("bye", StrType) == "bye"
-    assert mapper.serialize("other", StrType) == "other"
-
-    assert mapper.deserialize("hi", IntType) == "hi"
-    assert mapper.deserialize(2, IntType) == 2
-
-    assert mapper.deserialize("bye", StrType) == "bye"
-    assert mapper.deserialize("other", StrType) == "other"