JSON 架构属性的范围比预期的要广

Question

我在 Python3 中测试了以下 JSON 架构 (testschema.json)。我一直收到属性 "alpha" 的验证错误，我尝试以各种方式声明属性无济于事。

{
    "id": "testschema",
    "$schema": "http://json-schema.org/draft-04/schema#",
    "description": "test schema",

    "type": "object",
    "properties": {


        "traffic_parameters": {

            "properties": {

                "test_type": {

                    "type": "string",
                    "enum": ["AA", "BB"]
                },

                "capacity": {

                    "oneOf": [
                        {
                            "properties": {

                                "min_percentage": {

                                    "type": "integer",
                                    "minimum" : 1,
                                    "maximum" : 150,
                                    "additionalProperties": false
                                },

                                "max_percentage": {

                                    "type": "integer",
                                    "minimum" : 1,
                                    "maximum" : 150,
                                    "additionalProperties": false
                                }
                            },

                            "additionalProperties": false
                        },

                        {
                            "properties": {

                                "percentage_range": {

                                    "type": "array",
                                    "minItems": 1,
                                    "maxItems": 10,
                                    "items": {

                                        "type": "integer"
                                    },

                                   "additionalProperties": false
                                }
                            },

                            "additionalProperties": false
                        }                    
                    ]
                }
            },

            "additionalProperties": false
        },


        "alpha": {

            "properties": {

                "beta": {

                    "oneOf": [
                        {
                            "properties": {

                                "AA": {

                                    "a":   [90, 95],
                                    "b":   [4, 8],
                                    "additionalProperties": false
                                }
                            },

                            "additionalProperties": false
                        },

                        {
                            "properties": {

                                "BB": {

                                    "a":   [100],
                                    "b":   [0],
                                    "c": [0],
                                    "additionalProperties": false
                                }
                            },

                            "additionalProperties": false
                        },

                        {
                            "properties": {

                                "CC": {

                                    "a":   [50],
                                    "b":   [50],
                                    "additionalProperties": false
                                }
                            },

                            "additionalProperties": false
                        },

                        {
                            "properties": {

                                "DD": {

                                    "a":   [0],
                                    "b":   [0],
                                    "c": [100],
                                    "additionalProperties": false  
                                }
                            },

                            "additionalProperties": false
                        }
                    ]
                }
            },

            "additionalProperties": false
        }
    },

    "required": ["traffic_parameters", "alpha"]
}

这是使用此架构的测试 JSON (test.json)。

{
    "traffic_parameters": {

        "test_type": "BB",

        "capacity": {

            "percentage_range": [1,2,3,4,5,6]
        }
     },

    "alpha": {

        "beta": "AA"
    }
}

当我使用 Python3 jsonschema 模块验证时

with open("testschema.json") as schema_file:
    test_schema = json.load(schema_file)
schema_file.close()

with open("test.json") as json_file:
    test_json = json.load(json_file)
json_file.close()

validate(test_json, test_schema)

我在 alpha 属性上得到一个错误，它在结构上与 traffic_parameters 相似，但没有错误。

jsonschema.exceptions.ValidationError: 'AA' is valid under each of {'properties': {'BB': ...

这是输出

E
======================================================================
ERROR: test_valid__JSON_against_schema (__main__.SchemaTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test.py", line 35, in test_valid__JSON_against_schema
    validate(test_json, test_schema)
  File "/local/tools/PACKAGES/pyhton3/lib/python3.6/site-packages/jsonschema/validators.py", line 541, in validate
    cls(schema, *args, **kwargs).validate(instance)
  File "/local/tools/PACKAGES/pyhton3/lib/python3.6/site-packages/jsonschema/validators.py", line 130, in validate
    raise error
jsonschema.exceptions.ValidationError: 'AA' is valid under each of {'properties': {'BB': {'a': [100], 'b': [0], 'c': [0], 'additionalProperties': False}}, 'additionalProperties': False}, {'properties': {'CC': {'a': [50], 'b': [50], 'additionalProperties': False}}, 'additionalProperties': False}, {'properties': {'DD': {'a': [0], 'b': [0], 'c': [100], 'additionalProperties': False}}, 'additionalProperties': False}, {'properties': {'AA': {'a': [90, 95], 'b': [4, 8], 'additionalProperties': False}}, 'additionalProperties': False}

Failed validating 'oneOf' in schema['properties']['alpha']['properties']['beta']:
    {'oneOf': [{'additionalProperties': False,
                'properties': {'AA': {'a': [90, 95],
                                      'additionalProperties': False,
                                      'b': [4, 8]}}},
               {'additionalProperties': False,
                'properties': {'BB': {'a': [100],
                                      'additionalProperties': False,
                                      'b': [0],
                                      'c': [0]}}},
               {'additionalProperties': False,
                'properties': {'CC': {'a': [50],
                                      'additionalProperties': False,
                                      'b': [50]}}},
               {'additionalProperties': False,
                'properties': {'DD': {'a': [0],
                                      'additionalProperties': False,
                                      'b': [0],
                                      'c': [100]}}}]}

On instance['alpha']['beta']:
    'AA'

----------------------------------------------------------------------
Ran 1 test in 0.007s

FAILED (errors=1)

有谁知道这是为什么以及如何解决它？

谢谢。

Answer 1

我将把架构缩短到足以重现验证失败的程度：

{
    "id": "testschema",
    "$schema": "http://json-schema.org/draft-04/schema#",
    "description": "test schema",
    "type": "object",
    "properties": {
        "alpha": {
            "properties": {
                "beta": {
                    "oneOf": [
                        {
                            "properties": {
                                "AA": {
                                    "a":   [90, 95],
                                    "b":   [4, 8],
                                    "additionalProperties": false
                                }
                            },
                            "additionalProperties": false
                        },
                        {
                            "properties": {
                                "BB": {
                                    "a":   [100],
                                    "b":   [0],
                                    "c": [0],
                                    "additionalProperties": false
                                }
                            },
                            "additionalProperties": false
                        }
                    ]
                }
            },
            "additionalProperties": false
        }
    },
    "required": [ "alpha" ]
}

该错误表明未能验证 oneOf 约束，因为 "AA" 针对 oneOf 中列出的每个模式成功验证，并且 oneOf 要求它必须只匹配一个。

为什么 "AA" 针对每个模式进行验证？根本原因是模式没有为 oneOf 中列出的每个模式指定 "type" 信息。如 here 所述，如果没有为架构指定 "type"，则任何类型的任何有效 JSON 都可能与该架构匹配。要解决此问题，我们需要添加缺少的 "type" 约束。

通过查看架构和 JSON 示例，我不确定您想要实现什么。该模式似乎将 "AA"、"BB" 等描述为嵌套对象，但 JSON 示例似乎表明 "beta" 只需要映射到字符串值像 "AA".

如果 JSON 示例是正确的信息来源，您可以使用这样的模式解决问题。

schema = json.loads('''
{
    "id": "testschema",
    "$schema": "http://json-schema.org/draft-04/schema#",
    "description": "test schema",
    "type": "object",
    "properties": {
        "alpha": {
            "type": "object",
            "properties": {
                "beta": {
                    "type": "string",
                    "enum": [ "AA", "BB", "CC", "DD" ]
                }
            },
            "additionalProperties": false
        }
    },
    "required": [ "alpha" ]
}
''')

# valid
validate(json.loads('''
{
    "alpha": {
        "beta": "AA"
    }
}
'''), schema)

# valid
validate(json.loads('''
{
    "alpha": {
        "beta": "BB"
    }
}
'''), schema)

# invalid
validate(json.loads('''
{
    "alpha": {
        "beta": "ZZ"
    }
}
'''), schema)

Traceback (most recent call last):
  File "<stdin>", line 7, in <module>
  File "/Library/Python/2.7/site-packages/jsonschema/validators.py", line 541, in validate
    cls(schema, *args, **kwargs).validate(instance)
  File "/Library/Python/2.7/site-packages/jsonschema/validators.py", line 130, in validate
    raise error
jsonschema.exceptions.ValidationError: u'ZZ' is not one of [u'AA', u'BB', u'CC', u'DD']

Failed validating u'enum' in schema[u'properties'][u'alpha'][u'properties'][u'beta']:
    {u'enum': [u'AA', u'BB', u'CC', u'DD'], u'type': u'string'}

On instance[u'alpha'][u'beta']:
    u'ZZ'

OTOH，如果您的目标是 "AA"、"BB" 等成为子对象，那么您可以通过将架构更改为类似这样的内容来修复它。

schema = json.loads('''
{
    "id": "testschema",
    "$schema": "http://json-schema.org/draft-04/schema#",
    "description": "test schema",
    "type": "object",
    "properties": {
        "alpha": {
            "type": "object",
            "properties": {
                "beta": {
                    "oneOf": [
                        {
                            "type": "object",
                            "properties": {
                                "AA": {
                                    "type": "object",
                                    "properties": {
                                        "a": {
                                            "type": "array"
                                        }
                                    }
                                }
                            },
                            "additionalProperties": false
                        },
                        {
                            "type": "object",
                            "properties": {
                                "BB": {
                                    "type": "object",
                                    "properties": {
                                        "b": {
                                            "type": "array"
                                        }
                                    }
                                }
                            },
                            "additionalProperties": false
                        }
                    ]
                }
            },
            "additionalProperties": false
        }
    },
    "required": [ "alpha" ]
}
''')

# valid
validate(json.loads('''
{
    "alpha": {
        "beta": {
            "AA": {
                "a": [ 1 ]
            }
        }
    }
}
'''), schema)

# valid
validate(json.loads('''
{
    "alpha": {
        "beta": {
            "BB": {
                "b": [ 1 ]
            }
        }
    }
}
'''), schema)

# invalid
validate(json.loads('''
{
    "alpha": {
        "beta": {
            "ZZ": {
                "z": [ 1 ]
            }
        }
    }
}
'''), schema)
Traceback (most recent call last):
  File "<stdin>", line 11, in <module>
  File "/Library/Python/2.7/site-packages/jsonschema/validators.py", line 541, in validate
    cls(schema, *args, **kwargs).validate(instance)
  File "/Library/Python/2.7/site-packages/jsonschema/validators.py", line 130, in validate
    raise error
jsonschema.exceptions.ValidationError: {u'ZZ': {u'z': [1]}} is not valid under any of the given schemas

Failed validating u'oneOf' in schema[u'properties'][u'alpha'][u'properties'][u'beta']:
    {u'oneOf': [{u'additionalProperties': False,
                 u'properties': {u'AA': {u'properties': {u'a': {u'type': u'array'}},
                                         u'type': u'object'}},
                 u'type': u'object'},
                {u'additionalProperties': False,
                 u'properties': {u'BB': {u'properties': {u'b': {u'type': u'array'}},
                                         u'type': u'object'}},
                 u'type': u'object'}]}

On instance[u'alpha'][u'beta']:
    {u'ZZ': {u'z': [1]}}

# invalid
validate(json.loads('''
{
    "alpha": {
        "beta": {
            "AA": {
                "a": [ 1 ]
            },
            "BB": {
                "b": [ 1 ]
            }
        }
    }
}
'''), schema)

Traceback (most recent call last):
  File "<stdin>", line 14, in <module>
  File "/Library/Python/2.7/site-packages/jsonschema/validators.py", line 541, in validate
    cls(schema, *args, **kwargs).validate(instance)
  File "/Library/Python/2.7/site-packages/jsonschema/validators.py", line 130, in validate
    raise error
jsonschema.exceptions.ValidationError: {u'AA': {u'a': [1]}, u'BB': {u'b': [1]}} is not valid under any of the given schemas

Failed validating u'oneOf' in schema[u'properties'][u'alpha'][u'properties'][u'beta']:
    {u'oneOf': [{u'additionalProperties': False,
                 u'properties': {u'AA': {u'properties': {u'a': {u'type': u'array'}},
                                         u'type': u'object'}},
                 u'type': u'object'},
                {u'additionalProperties': False,
                 u'properties': {u'BB': {u'properties': {u'b': {u'type': u'array'}},
                                         u'type': u'object'}},
                 u'type': u'object'}]}

On instance[u'alpha'][u'beta']:
    {u'AA': {u'a': [1]}, u'BB': {u'b': [1]}}

无论哪种方式，重要的是确保 "type" 在必要时指定信息。

JSON 架构 属性 的范围比预期的要广

JSON schema property has wider scope than expected

python

json

jsonschema

JSON 架构属性的范围比预期的要广