1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
|
# Copyright (c) 2022 Tulir Asokan
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
from typing import Type, TypeVar, Union
from abc import ABC, abstractmethod
from enum import Enum
import json
from ..primitive import JSON
SerializableSubtype = TypeVar("SerializableSubtype", bound="SerializableAttrs")
class Serializable:
"""Serializable is the base class for types with custom JSON serializers."""
def serialize(self) -> JSON:
"""Convert this object into objects directly serializable with `json`."""
raise NotImplementedError()
@classmethod
def deserialize(cls: Type[SerializableSubtype], raw: JSON) -> SerializableSubtype:
"""Convert the given data parsed from JSON into an object of this type."""
raise NotImplementedError()
def json(self) -> str:
"""Serialize this object and dump the output as JSON."""
return json.dumps(self.serialize())
@classmethod
def parse_json(cls: Type[SerializableSubtype], data: Union[str, bytes]) -> SerializableSubtype:
"""Parse the given string as JSON and deserialize the result into this type."""
return cls.deserialize(json.loads(data))
class SerializerError(Exception):
"""
SerializerErrors are raised if something goes wrong during serialization or deserialization.
"""
pass
class UnknownSerializationError(SerializerError):
def __init__(self) -> None:
super().__init__("Unknown serialization error")
class AbstractSerializable(ABC, Serializable):
"""
An abstract Serializable that adds ``@abstractmethod`` decorators.
"""
@abstractmethod
def serialize(self) -> JSON:
pass
@classmethod
@abstractmethod
def deserialize(cls: Type[SerializableSubtype], raw: JSON) -> SerializableSubtype:
pass
class SerializableEnum(Serializable, Enum):
"""
A simple Serializable implementation for Enums.
Examples:
>>> class MyEnum(SerializableEnum):
... FOO = "foo value"
... BAR = "hmm"
>>> MyEnum.FOO.serialize()
"foo value"
>>> MyEnum.BAR.json()
'"hmm"'
"""
def __init__(self, _) -> None:
"""
A fake ``__init__`` to stop the type checker from complaining.
Enum's ``__new__`` overrides this.
"""
super().__init__()
def serialize(self) -> str:
"""
Convert this object into objects directly serializable with `json`, i.e. return the value
set to this enum value.
"""
return self.value
@classmethod
def deserialize(cls: Type[SerializableSubtype], raw: str) -> SerializableSubtype:
"""
Convert the given data parsed from JSON into an object of this type, i.e. find the enum
value for the given string using ``cls(raw)``.
"""
try:
return cls(raw)
except ValueError as e:
raise SerializerError() from e
def __str__(self):
return str(self.value)
def __repr__(self):
return f"{self.__class__.__name__}.{self.name}"
|
