Map enum int's into Enums redux (#293)

Re-implement Enum to be faster along with being an open set

---------
Co-authored-by: ydylla <ydylla@gmail.com>

tests/inputs/enum/test_enum.py

@@ -82,3 +82,23 @@ def test_repeated_enum_with_non_list_iterables_to_dict():
         yield Choice.THREE
 
     assert Test(choices=enum_generator()).to_dict()["choices"] == ["ONE", "THREE"]
+
+
+def test_enum_mapped_on_parse():
+    # test default value
+    b = Test().parse(bytes(Test()))
+    assert b.choice.name == Choice.ZERO.name
+    assert b.choices == []
+
+    # test non default value
+    a = Test().parse(bytes(Test(choice=Choice.ONE)))
+    assert a.choice.name == Choice.ONE.name
+    assert b.choices == []
+
+    # test repeated
+    c = Test().parse(bytes(Test(choices=[Choice.THREE, Choice.FOUR])))
+    assert c.choices[0].name == Choice.THREE.name
+    assert c.choices[1].name == Choice.FOUR.name
+
+    # bonus: defaults after empty init are also mapped
+    assert Test().choice.name == Choice.ZERO.name

tests/test_enum.py

@@ -0,0 +1,79 @@
+from typing import (
+    Optional,
+    Tuple,
+)
+
+import pytest
+
+import betterproto
+
+
+class Colour(betterproto.Enum):
+    RED = 1
+    GREEN = 2
+    BLUE = 3
+
+
+PURPLE = Colour.__new__(Colour, name=None, value=4)
+
+
+@pytest.mark.parametrize(
+    "member, str_value",
+    [
+        (Colour.RED, "RED"),
+        (Colour.GREEN, "GREEN"),
+        (Colour.BLUE, "BLUE"),
+    ],
+)
+def test_str(member: Colour, str_value: str) -> None:
+    assert str(member) == str_value
+
+
+@pytest.mark.parametrize(
+    "member, repr_value",
+    [
+        (Colour.RED, "Colour.RED"),
+        (Colour.GREEN, "Colour.GREEN"),
+        (Colour.BLUE, "Colour.BLUE"),
+    ],
+)
+def test_repr(member: Colour, repr_value: str) -> None:
+    assert repr(member) == repr_value
+
+
+@pytest.mark.parametrize(
+    "member, values",
+    [
+        (Colour.RED, ("RED", 1)),
+        (Colour.GREEN, ("GREEN", 2)),
+        (Colour.BLUE, ("BLUE", 3)),
+        (PURPLE, (None, 4)),
+    ],
+)
+def test_name_values(member: Colour, values: Tuple[Optional[str], int]) -> None:
+    assert (member.name, member.value) == values
+
+
+@pytest.mark.parametrize(
+    "member, input_str",
+    [
+        (Colour.RED, "RED"),
+        (Colour.GREEN, "GREEN"),
+        (Colour.BLUE, "BLUE"),
+    ],
+)
+def test_from_string(member: Colour, input_str: str) -> None:
+    assert Colour.from_string(input_str) == member
+
+
+@pytest.mark.parametrize(
+    "member, input_int",
+    [
+        (Colour.RED, 1),
+        (Colour.GREEN, 2),
+        (Colour.BLUE, 3),
+        (PURPLE, 4),
+    ],
+)
+def test_try_value(member: Colour, input_int: int) -> None:
+    assert Colour.try_value(input_int) == member